Diana and Roger married whenPage 75 he was 38 and she was 34. Both worked full-time and were excited when Diana became pregnant. Two months later, Diana began to have some unusual pains and bleeding. Just two months into her pregnancy she lost the baby. Although most early miscarriages are the result of embryonic defects, Diana thought deeply about why she had been unable to carry the baby to full term, and felt guilty that she might have done something “wrong.”

Six months later, Diana became pregnant again. Because she was still worried about her prior loss, she made sure to follow every government recommendation such as getting enough folic acid, avoiding certain types of dairy products that might harbor bacteria, and letting someone else change their cat’s litterbox to avoid toxoplasmosis. She and Roger read about pregnancy and signed up for birth preparation classes. Each Friday night for eight weeks they practiced techniques for dealing with contractions. They talked about what kind of parents they wanted to be and discussed what changes in their lives the baby would make. When they found out that their offspring was going to be a boy, they gave him a nickname: Mr. Littles.

Alex, also known as “Mr. Littles.” Courtesy of Dr. John Santrock

This time, Diana’s pregnancy went well, and Alex, also known as Mr. Littles, was born. During the birth, however, Diana’s heart rate dropped precipitously, and she was given a stimulant to raise it. Apparently the stimulant also increased Alex’s heart rate and breathing to a dangerous point, and he had to be placed in a neonatal intensive care unit (NICU).

Several times a day, Diana and Roger visited Alex in the NICU. A number of babies in the NICU with very low birth weights had been in intensive care for weeks, and some of the babies were not doing well. Fortunately, Alex was in better health. After he had spent several days in the NICU, his parents were permitted to take home a very healthy Alex.

topical connections looking back

Genes form the biological basis of our development. They are passed on through mitosis, meiosis, and, ultimately, fertilization. The impact of our genes involves the genetic principles of dominant-recessive genes, sex-linked genes, genetic imprinting, and polygenically determined characteristics. Approximately 10 to 15 percent of U.S. couples have problems with fertility. Some of these problems can be solved through surgery, drugs, or in vitro fertilization. Whether a pregnancy occurs naturally or with assistance, the resulting infant’s development is shaped both by his or her genes (nature) and environment (nurture).

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This chapter chronicles the truly remarkable developments from conception through birth. Imagine . . . at one time you were an organism floating in a sea of fluid in your mother’s womb. Let’s now explore what your development was like from the time you were conceived through the time you were born. We will explore normal development in the prenatal period, as well as the period’s hazards (such as high levels of mercury that were mentioned in the preceding story). We also will study the birth process and tests used to assess the newborn; discuss parents’ adjustment during the postpartum period; and evaluate parent-infant bonding.

1 Prenatal Development

LG1 Describe prenatal development.

The Course of Prenatal Development

Teratology and Hazards to Prenatal Development

Prenatal Care

Normal Prenatal Development

Imagine how Alex (“Mr. Littles”) came to be. Out of thousands of eggs and millions of sperm, one egg and one sperm united to produce him. Had the union of sperm and egg come a day or even an hour earlier or later, he might have been very different—maybe even of the opposite sex. Conception occurs when a single sperm cell from the male unites with an ovum (egg) in the female’s fallopian tube in a process called fertilization. Over the next few months, the genetic code discussed in the “Biological Beginnings” chapter directs a series of changes in the fertilized egg, but many events and hazards will influence how that egg develops and becomes tiny Alex.

The history of man for the nine months preceding his birth would, probably, be far more interesting, and contain events of greater moment, than all the three score and ten years that follow it.

—Samuel Taylor Coleridge

English Poet and Essayist, 19th Century

THE COURSE OF PRENATAL DEVELOPMENT

Typical prenatal development, which begins with fertilization and ends with birth, takes between 266 and 280 days (38 to 40 weeks). It can be divided into three periods: germinal, embryonic, and fetal.

The Germinal Period The germinal period is the period of prenatal development that takes place during the first two weeks after conception. It includes the creation of the fertilized egg, called a zygote; cell division; and the attachment of the zygote to the uterine wall.

Rapid cell division by the zygote continues throughout the germinal period (recall that this cell division occurs through a process called mitosis). Differentiation—specialization of cells to perform various tasks—starts to take place by approximately one week after conception. At this stage, the group of cells, now called the blastocyst , consists of an inner mass of cells that will eventually develop into the embryo, and the trophoblast , an outer layer of cells that later provides nutrition and support for the embryo. Implantation, the attachment of the zygote to the uterine wall, takes place about 11 to 15 days after conception. Figure 1illustrates some of the most significant developments during the germinal period.

FIGURE 1 Significant Developments in the Germinal Period. Just one week after conception, cells of the blastocyst have already begun specializing. The germinal period ends when the blastocyst attaches to the uterine wall. Which of the steps shown in the drawing occur in the laboratory when IVF is used?

The Embryonic Period The embryonic period is the period of prenatal development that occurs from two to eight weeks after conception. During the embryonic period, the rate of cell differentiation intensifies, support systems for cells form, and organs appear.

This period begins as the blastocyst attaches to the uterine wall. The mass of cells is now called an embryo, and three layers of cells form. The embryo’s endoderm is the inner layer of cells, which will develop into the digestive and respiratory systems. The mesoderm is the middle layer, which will become the circulatory system, bones, muscles, excretory system, and reproductive system. The ectoderm is the outermost layer, which will become the nervous system and brain, sensory receptors (ears, nose, and eyes, for example), and skin parts (hair and nails, for example). Every body part eventually develops from these three layers. The endoderm primarily produces internal body parts, the mesoderm primarily produces parts that surround the internal areas, and the ectoderm primarily produces surface parts.

As the embryo’s three layers form, life-support systems for the embryoPage 77 develop rapidly. These life-support systems include the amnion, the umbilical cord (both of which develop from the fertilized egg, not the mother’s body), and the placenta. The amnion is a sac (bag or envelope) that contains a clear fluid in which the developing embryo floats. The amniotic fluid provides an environment that is temperature and humidity controlled, as well as shockproof. The umbilical cord contains two arteries and one vein, and connects the baby to the placenta. The placenta consists of a disk-shaped group of tissues in which small blood vessels from the mother and the offspring intertwine but do not join.

Figure 2 illustrates the placenta, the umbilical cord, and the blood flow in the expectant mother and developing organism. Very small molecules—oxygen, water, salt, food from the mother’s blood, as well as carbon dioxide and digestive wastes from the offspring’s blood—pass back and forth between the mother and embryo or fetus (Cuffe & others, 2017; Dube, Desparois, & Lafond, 2018). Virtually any drug or chemical substance the pregnant woman ingests can cross the placenta to some degree, unless it is metabolized or altered during passage, or the molecules are too large to pass through the placental wall (Pfeifer & Bunders, 2016). Of special concern is the transfer through the placenta of drugs that can be harmful to the fetus, such as alcohol, nicotine, marijuana, and cocaine (Koren & Ornoy, 2018). For example, one study confirmed that ethanol crosses the human placenta and primarily reflects maternal alcohol use (Matlow & others, 2013). Another study revealed that cigarette smoke weakened and increased the oxidative stress of fetal membranes, from which the placenta develops (Menon & others, 2011). The stress hormone cortisol also can cross the placenta (Parrott & others, 2014). Large molecules that cannot pass through the placental wall include red blood cells and harmful substances, such as most bacteria, maternal wastes, and hormones. The complex mechanisms that govern the transfer of substances across the placental barrier are still not entirely understood (Huckle, 2017; Jeong & others, 2018; Vaughan & others, 2017; Zhang & others, 2018).

FIGURE 2 The Placenta and the Umbilical Cord. The area bound by the square is enlarged in the right half of the illustration. Arrows indicate the direction of blood flow. Maternal blood flows through the uterine arteries to the spaces housing the placenta, and it returns through the uterine veins to the maternal circulation. Fetal blood flows through the umbilical arteries into the capillaries of the placenta and returns through the umbilical vein to the fetal circulation. The exchange of materials takes place across the layer separating the maternal and fetal blood supplies, so the bloods never come into contact. What is known about how the placental barrier works and its importance?

By the time most women know they are pregnant, the major organs have begun to form. Organogenesis is the name given to the process of organ formation during the first two months of prenatal development. While they are being formed, the organs are especially vulnerable to environmental changes (Rios & Clevers, 2018; Schittny, 2017). In the third week after conception, the neural tube that eventually becomes the spinal cord forms. At about 21 days, eyes begin to appear, and at 24 days the cells for the heart begin to differentiate. During the fourth week, the urogenital system becomes apparent, and armPage 78 and leg buds emerge. Four chambers of the heart take shape, and blood vessels appear. From the fifth to the eighth week, arms and legs differentiate further; at this time, the face starts to form but still is not very recognizable. The intestinal tract develops and the facial structures fuse. At eight weeks, the developing organism weighs about 1/30 ounce and is just over 1 inch long.

The Fetal Period The fetal period , lasting about seven months, is the prenatal period between two months after conception and birth in typical pregnancies. Growth and development continue their dramatic course during this time.

Three months after conception (13 weeks), the fetus is about 3 inches long and weighs about four-fifths of an ounce. Its arms, legs, and head move randomly (or spontaneously), and its mouth opens and closes. The face, forehead, eyelids, nose, and chin are distinguishable, as are the upper arms, lower arms, hands, and lower limbs. In most cases, the genitals can be identified as male or female. By the end of the fourth month of pregnancy (17 weeks), the fetus has grown to about 5.5 inches in length and weighs about 5 ounces. At this time, a growth spurt occurs in the body’s lower parts. For the first time, the mother can feel the fetus move.

By the end of the fifth month (22 weeks), the fetus is about 12 inches long and weighs close to a pound. Structures of the skin have formed—toenails and fingernails, for example. The fetus is more active, showing a preference for a particular position in the womb. By the end of the sixth month (26 weeks), the fetus is about 14 inches long and has gained another half pound to a pound. The eyes and eyelids are completely formed, and a fine layer of hair covers the head. A grasping reflex is present and irregular breathing movements occur.

As early as six months of pregnancy (about 24 to 25 weeks after conception), the fetus for the first time has a chance of surviving outside the womb—that is, it is viable. Infants who are born early, or between 24 and 37 weeks of pregnancy, usually need help breathing because their lungs are not yet fully mature. By the end of the seventh month, the fetus is about 16 inches long and weighs about 3 pounds.

During the last two months of prenatal development, fatty tissues develop, and the functioning of various organ systems—heart and kidneys, for example—steps up. During the eighth and ninth months, the fetus grows longer and gains substantial weight—about another 4 pounds. At birth, the average American baby weighs 8 pounds and is about 20 inches long.

Figure 3 gives an overview of the main events during prenatalPage 79 development. Notice that instead of describing development in terms of germinal, embryonic, and fetal periods, Figure 3 divides prenatal development into equal periods of three months, called trimesters. Remember that the three trimesters are not the same as the three prenatal periods we have discussed. The germinal and embryonic periods occur in the first trimester. The fetal period begins toward the end of the first trimester and continues through the second and third trimesters. Viability (the chances of surviving outside the womb) begins at the end of the second trimester.

FIGURE 3 The Three Trimesters of Prenatal Development. Both the germinal and embryonic periods occur during the first trimester. The end of the first trimester as well as the second and third trimesters are part of the fetal period. (Top) ©David Spears/PhotoTake, Inc.; (middle) ©Neil Bromhall/Science Source; (bottom) ©Brand X Pictures/PunchStock

developmental connection

Brain Development

At birth, infants’ brains weigh approximately 25 percent of what they will weigh in adulthood. Connect to “Physical Development in Infancy.”

Brain Development One of the most remarkable aspects of the prenatal period is the development of the brain (Andescavage & others, 2017). By the time babies are born, it has been estimated that they have as many as 20 to 100 billion neurons , or nerve cells, which handle information processing at the cellular level in the brain. During prenatal development, neurons spend time moving to the right locations and are starting to become connected. The basic architecture of the human brain is assembled during the first two trimesters of prenatal development. In typical development, the third trimester of prenatal developmentPage 80 and the first two years of postnatal life are characterized by gradual increases in connectivity and functioning of neurons.

Four important phases of the brain’s development during the prenatal period involve: (1) the neural tube, (2) neurogenesis, (3) neuronal migration, and (4) neural connectivity.

Neural Tube As the human embryo develops inside its mother’s womb, the nervous system begins forming as a long, hollow tube located on the embryo’s back. This pear-shaped neural tube, which forms at about 18 to 24 days after conception, develops out of the ectoderm. The tube closes at the top and bottom ends at about 27 days after conception (Keunen, Counsell, & Bender, 2017). Figure 4 shows that the nervous system still has a tubular appearance six weeks after conception.

FIGURE 4 Early Formation of the Nervous System. The photograph shows the primitive, tubular appearance of the nervous system at six weeks in the human embryo. ©Claude Edelmann/Science Source

Two birth defects related to a failure of the neural tube to close are anencephaly and spina bifida. The highest regions of the brain fail to develop when fetuses have anencephaly or when the head end of the neural tube fails to close, and these fetuses die in the womb, during childbirth, or shortly after birth (Steric & others, 2015). Spina bifida results in varying degrees of paralysis of the lower limbs (Li & others, 2018; Miller, 2017). Individuals with spina bifida usually need assistive devices such as crutches, braces, or wheelchairs (Grivell, Andersen, & Dodd, 2014). Both maternal diabetes and obesity place the fetus at risk for developing neural tube defects (Yu, Wu, & Yang, 2016). Also, one study found that maternal exposure to secondhand tobacco smoke was linked to neural tube defects (Suarez & others, 2011). Further, one study revealed that a high level of maternal stress during pregnancy was associated with neural tube defects in offspring (Li & others, 2013). A strategy that can help to prevent neural tube defects is for pregnant women to take adequate amounts of the B vitamin folic acid (Li & others, 2018; Viswanathan & others, 2017). A recent large-scale study in Brazil found that fortifying flour with folic acid significantly reduced the rate of neural tube defects (Santos & others, 2016).

Neurogenesis In a normal pregnancy, once the neural tube has closed, a massive proliferation of new immature neurons begins to takes place at about the fifth prenatal week and continues throughout the remainder of the prenatal period. The generation of new neurons is called neurogenesis , a process that continues through the remainder of the prenatal period but is largely complete by the end of the fifth month after conception (Keunen, Counsell, & Benders, 2017). At the peak of neurogenesis, it is estimated that as many as 200,000 neurons are generated every minute.

Neuronal Migration At approximately 6 to 24 weeks after conception, neuronal migration occurs. This involves cells moving outward from their point of origin to their appropriate locations and creating the different levels, structures, and regions of the brain (Keunen, Counsell, & Benders, 2017). Once a cell has migrated to its target destination, it must mature and develop a more complex structure.

Neural Connectivity At about the 23rd prenatal week, connections between neurons begin to occur, a process that continues postnatally (Miller, Huppi, & Mallard, 2016). We will have much more to say about the structure of neurons, their connectivity, and the development of the infant brain in the chapter on “Physical Development in Infancy.”

TERATOLOGY AND HAZARDS TO PRENATAL DEVELOPMENT

For Alex, the baby discussed at the opening of this chapter, the course of prenatal development went smoothly. His mother’s womb protected him as he developed. Despite this protection, the environment can affect the embryo or fetus in many well-documented ways.

Yelyi Nordone, 12, of New York City, casts her line out into the pond during Camp Spifida at Camp Victory, near Millville, Pennsylvania. Camp Spifida is a week-long residential camp for children with spina bifida. ©Bill Hughes/AP Images

General Principles A teratogen is any agent that can potentially cause a birth defect or negatively alter cognitive and behavioral outcomes. (The word comes from the Greek word tera, meaning “monster.”) So many teratogens exist that practically every fetus is exposed to at least some teratogens. For this reason, it is difficult to determine which teratogen causes which problem. In addition, it may take a long time for the effects of a teratogen to show up. Only about half of all potential effects appear at birth.

The field of study that investigates the causes of birth defects isPage 81 called teratology (Boschen & others, 2018; Cassina & others, 2017). Some exposures to teratogens do not cause physical birth defects but can alter the developing brain and influence cognitive and behavioral functioning. These deficits in functioning are explored by researchers in the field of behavioral teratology.

The dose, genetic susceptibility, and the time of exposure to a particular teratogen influence both the severity of the damage to an embryo or fetus and the type of defect:

· Dose. The dose effect is rather obvious—the greater the dose of an agent, such as a drug, the greater the effect.

· Genetic susceptibility. The type or severity of abnormalities caused by a teratogen is linked to the genotype of the pregnant woman and the genotype of the embryo or fetus (Lin & others, 2017). For example, how a mother metabolizes a particular drug can influence the degree to which the drug’s effects are transmitted to the embryo or fetus. The extent to which an embryo or fetus is vulnerable to a teratogen may also depend on its genotype (Middleton & others, 2017). Also, for unknown reasons, male fetuses are far more likely to be affected by teratogens than female fetuses.

· Time of exposure. Exposure to teratogens does more damage when it occurs at some points in development than at others (Feldkamp & others, 2017). Damage during the germinal period may even prevent implantation. In general, the embryonic period is more vulnerable than the fetal period.

Figure 5 summarizes additional information about the effects of time of exposure to a teratogen. The probability of a structural defect is greatest early in the embryonic period, when organs are being formed (Mazzu-Nascimento & others, 2017). Each body structure has its own critical period of formation. Recall from earlier discussions that a critical period is a fixed time period very early in development during which certain experiences or events can have a long-lasting effect on development. The critical periodPage 82 for the nervous system (week 3) is earlier than for arms and legs (weeks 4 and 5). Exposure to teratogens in the fetal period is more likely to cause problems in how organs function and may result in stunted growth rather than structural damage.

FIGURE 5 Teratogens and the Timing of Their Effects on Prenatal Development. The danger of structural defects caused by teratogens is greatest early in embryonic development. The period of organogenesis (red color) lasts for about six weeks. Later assaults by teratogens (blue-green color) mainly occur in the fetal period and instead of causing structural damage are more likely to stunt growth or cause problems involving organ function.

After organogenesis is complete, teratogens are less likely to cause anatomical defects. Instead, exposure during the fetal period is more likely to stunt growth or to create problems in the way organs function. This is especially true for the developing fetal brain, which continues to develop connections throughout pregnancy. To examine some key teratogens and their effects, let’s begin with drugs.

Prescription and Nonprescription Drugs Many U.S. women are given prescriptions for drugs while they are pregnant—especially antibiotics, analgesics, and asthma medications. Prescription as well as nonprescription drugs, however, may have effects on the embryo or fetus that the women never imagine.

Prescription drugs that can function as teratogens include antibiotics, such as streptomycin and tetracycline; some antidepressants; certain hormones, such as progestin and synthetic estrogen; and Accutane (the trade name for isotretinoin, a form of Vitamin A that is often used to treat acne) (Brown & others, 2018; Dathe & Schaefer, 2018). Among the birth defects caused by Accutane are heart defects, eye and ear abnormalities, and brain malformation. In a recent study, isotretinoin was the fourth most common drug given to female adolescents who were seeking contraception advice from a physician (Stancil & others, 2017). However, physicians did not give the adolescent girls adequate information about the negative effects of isotretinoin on offspring if the girls were to become pregnant. In a recent review of teratogens that should never be taken during the first trimester of pregnancy, isotretinoin was on the prohibited list (Eltonsy & others, 2016).

Nonprescription drugs that can be harmful include diet pills and high dosages of aspirin (Cadavid, 2017). Research indicates that low doses of aspirin pose no harm for the fetus but that high doses can contribute to maternal and fetal bleeding (Osikoya & others, 2017).

Psychoactive Drugs Psychoactive drugs act on the nervous system to alter states of consciousness, modify perceptions, and change moods. Examples include caffeine, alcohol, and nicotine, as well as illicit drugs such as cocaine, marijuana, and heroin.

Caffeine People often consume caffeine when they drink coffee, tea, or cola, or when they eat chocolate. Somewhat mixed results have been found for the extent to which maternal caffeine intake influences an offspring’s development (Adams, Keisberg, & Safranek, 2016; de Medeiros & others, 2017). However, a large-scale study of almost 60,000 women revealed that maternal caffeine intake was linked to lower birth weight and babies being born small for gestational age (Sengpiel & others, 2013). Also, the influence of maternal consumption of highly caffeinated energy drinks on the development of offspring has not yet been studied. The U.S. Food and Drug Administration recommends that pregnant women either not consume caffeine or consume it only sparingly.

Fetal alcohol spectrum disorders (FASD) are characterized by a number of physical abnormalities and learning problems. Notice the wide-set eyes, flat cheekbones, and thin upper lip in this child with FASD. ©Streissguth, A.P., Landesman-Dwyer S., Martin, J.C., & Smith, D.W. (1980). Teratogenic effects of alcohol in humans and laboratory animals. Science, 209, 353–361.

Alcohol Heavy drinking by pregnant women can be devastating to their offspring (Jacobson & others, 2017). Fetal alcohol spectrum disorders (FASD) are a cluster of abnormalities and problems that appear in the offspring of mothers who drink alcohol heavily during pregnancy (Del Campo & Jones, 2017; Helgesson & others, 2018). The abnormalities include facial deformities and defects of the limbs and heart (Pei & others, 2017; Petrenko & Alto, 2017). Most children with FASD have learning problems and many are below average in intelligence, with some having an intellectual disability (Khoury & Milligan, 2017). Also, in a recent study in the United Kingdom, the life expectancy of individuals with FASD was only 34 years of age, about 42 percent of the average life expectancy in the general population (Thanh & Jonsson, 2016). In this study, the most common causes of death among individuals with FASD were suicide (15 percent), accidents (14 percent), and poisoning by illegal drugs or alcohol (7 percent). A recent research review concluded that FASD is linked to a lower level of executive function in children, especially in planning (Kingdon, Cardoso, & McGrath, 2016). And in a recent study, FASD was associated with both externalized and internalized behavior problems in childhood (Tsang & others, 2016). Although many mothers of FASD infants are heavy drinkers, many mothers who are heavy drinkers do not have children with FASD or have one child with FASD and other children who do not have it.

What are some guidelines for alcohol use during pregnancy?Page 83 Even drinking just one or two servings of beer or wine or one serving of hard liquor a few days a week can have negative effects on the fetus, although it is generally agreed that this level of alcohol use will not cause fetal alcohol syndrome (Valenzuela & others, 2012; Sarman, 2018). The U.S. Surgeon General recommends that no alcohol be consumed during pregnancy, as does the French Alcohol Society (Rolland & others, 2016). Despite such recommendations, a recent large-scale U.S. study found that 11.5 percent of adolescent and 8.7 percent of adult pregnant women reported using alcohol in the previous month (Oh & others, 2017).

However, in Great Britain, the National Institutes of Care and Health Excellence have concluded that it is safe to consume one to two drinks not more than twice a week during pregnancy (O’Keeffe, Greene, & Kearney, 2014). Nonetheless, some research suggests that it may not be wise to consume alcohol at the time of conception.

Nicotine Cigarette smoking by pregnant women can also adversely influence prenatal development, birth, and postnatal development (Shisler & others, 2017). Preterm births and low birth weights, fetal and neonatal deaths, respiratory problems, and sudden infant death syndrome (SIDS, also known as crib death) are all more common among the offspring of mothers who smoked during pregnancy (Zhang & others, 2017). Prenatal smoking has been implicated in as many as 25 percent of infants being born with a low birth weight (Brown & Graves, 2013).

What are some links between expectant mothers’ nicotine intake and outcomes for their offspring? ©Bubbles Photolibrary/Alamy

Maternal smoking during pregnancy also has been identified as a risk factor for the development of attention deficit hyperactivity disorder in offspring (Pohlabein & others, 2017; Weissenberger & others, 2017). A recent meta-analysis of 15 studies concluded that smoking during pregnancy increased the risk that children would have ADHD, and the risk of ADHD was greater for children whose mothers were heavy smokers (Huang & others, 2018). And in a recent study, maternal cigarette smoking during pregnancy was linked to higher rates of cigarette smoking among offspring at 16 years of age (De Genna & others, 2016). Further, a recent study revealed that daughters whose mothers smoked during their pregnancy were more likely to subsequently smoke during their own pregnancy (Ncube & Mueller, 2017). Studies also indicate that environmental tobacco smoke is linked to impaired connectivity of the thalamus and prefrontal cortex in newborns (Salzwedel & others, 2016). Another study found that maternal exposure to environmental tobacco smoke during prenatal development increased the risk of stillbirth (Varner & others, 2014). Also, one study found that maternal smoking during pregnancy was associated with increased risk of asthma and wheezing in adolescence (Hollams & others, 2014).

Despite the plethora of negative outcomes for maternal smoking during pregnancy, a recent large-scale U.S. study revealed that 23 percent of adolescent and 15 percent of adult pregnant women reported using tobacco in the previous month (Oh & others, 2017). And a final point about nicotine use during pregnancy involves the recent dramatic increase in the use of e-cigarettes (Wagner, Camerota, & Propper, 2017; Tegin & others, 2018). A recent study found that misconceptions about e-cigarettes were common among pregnant women (Mark & others, 2015). Women who were using e-cigarettes during pregnancy often stated that e-cigarettes were less harmful than regular cigarettes (74 percent) and helpful in easing smoking cessation (72 percent).

Cocaine Does cocaine use during pregnancy harm the developing embryo and fetus? A research review concluded that cocaine quickly crosses the placenta to reach the fetus (De Giovanni & Marchetti, 2012). The most consistent finding is that cocaine exposure during prenatal development is associated with reduced birth weight, length, and head circumference (Gouin & others, 2011). Also, in other studies, prenatal cocaine exposure has been linked to impaired connectivity of the thalamus and prefrontal cortex in newborns (Salzwedel & others, 2016); impaired motor development at 2 years of age and a slower rate of growth through 10 years of age (Richardson, Goldschmidt, & Willford, 2008); self-regulation problems at age 12 (Minnes & others, 2016); elevated blood pressure at 9 years of age (Shankaran & others, 2010); impaired language development and information processing (Beeghly & others, 2006), including attention deficits (especially impulsivity) (Accornero & others, 2006; Richardson & others, 2011); learning disabilities at age 7 (Morrow & others, 2006); increased likelihood of being in a special education program that involves supportive services (Levine & others, 2008); and increased behavioral problems, especially externalizing problems such as high rates of aggression and delinquency (Minnes & others, 2010; Richardson & others, 2011).

This baby was exposed to cocaine prenatally. What are some of the possible developmental effects of prenatal exposure to cocaine? ©Chuck Nacke/Alamy

Some researchers argue that these findings should be interpreted cautiously (Accornero & others, 2006). Why? Because other factors in the lives of pregnant women who use cocaine (such as poverty, malnutrition, and other substance abuse) often cannot be ruled out as possible contributors to the problems found in theirPage 84 children (Hurt & others, 2005; Messiah & others, 2011). For example, cocaine users are more likely than nonusers to smoke cigarettes, use marijuana, drink alcohol, and take amphetamines.

Despite these cautions, the weight of research evidence indicates that children born to mothers who use cocaine are likely to have neurological, medical, and cognitive deficits (Cain, Bornick, & Whiteman, 2013; Field, 2007; Martin & others, 2016; Mayer & Zhang, 2009; Parcianello & others, 2018; Richardson & others, 2011; Scott-Goodwin, Puerto, & Moreno, 2016). Cocaine use by pregnant women is never recommended.

Marijuana An increasing number of studies find that marijuana use by pregnant women also has negative outcomes for offspring (Ruisch & others, 2018; Volkow, Compton, & Wargo, 2017). For example, researchers found that prenatal marijuana exposure was related to lower intelligence in children (Goldschmidt & others, 2008). Research reviews concluded that marijuana use during pregnancy alters brain functioning in the fetus (Calvigioni & others, 2014; Jaques & others, 2014). In a recent meta-analysis, marijuana use during pregnancy was linked to offsprings’ low birth weight and greater likelihood of being placed in a neonatal intensive care unit (Gunn & others, 2016). One study also indicated that prenatal exposure to marijuana was linked to marijuana use at 14 years of age (Day, Goldschmidt, & Thomas, 2006). Another study discovered that marijuana use by pregnant women was associated with stillbirth (Varner & others, 2014). In sum, marijuana use is not recommended for pregnant women.

Despite increasing evidence of negative outcomes, a recent survey found that marijuana use by pregnant women increased from 2.4 percent in 2002 to 3.85 percent in 2014 (Brown & others, 2016). And there is considerable concern that marijuana use by pregnant women may increase further given the growing number of states that have legalized marijuana (Chasnoff, 2017; Hennessy, 2018).

Heroin It is well documented that infants whose mothers are addicted to heroin show several behavioral difficulties at birth (Angelotta & Appelbaum, 2017). The difficulties include withdrawal symptoms, such as tremors, irritability, abnormal crying, disturbed sleep, and impaired motor control. Many still show behavioral problems at their first birthday, and attention deficits may appear later in development. The most common treatment for heroin addiction, methadone, is associated with very severe withdrawal symptoms in newborns (Lai & others, 2017).

Incompatible Blood Types Incompatibility between the mother’s and father’s blood types poses another risk to prenatal development (Yogev-Lifshitz & others, 2016). Blood types are created by differences in the surface structure of red blood cells. One type of difference in the surface of red blood cells creates the familiar blood groups—A, B, O, and AB. A second difference creates what is called Rh-positive and Rh-negative blood. If a surface marker, called the Rh-factor, is present in an individual’s red blood cells, the person is said to be Rh-positive; if the Rh-marker is not present, the person is said to be Rh-negative. If a pregnant woman is Rh-negative and her partner is Rh-positive, the fetus may be Rh-positive. If the fetus’ blood is Rh-positive and the mother’s is Rh-negative, the mother’s immune system may produce antibodies that will attack the fetus. This can result in any number of problems, including miscarriage or stillbirth, anemia, jaundice, heart defects, brain damage, or death soon after birth (Fasano, 2017).

An explosion at the Chernobyl nuclear power plant in the Ukraine produced radioactive contamination that spread to surrounding areas. Thousands of infants were born with health problems and deformities as a result of the nuclear contamination, including this boy whose arm did not form. In addition to radioactive contamination, what are some other types of environmental hazards to prenatal development? ©Sergey Guneev/RIA Novosti

Generally, the first Rh-positive baby of an Rh-negative mother is not at risk, but with each subsequent pregnancy the risk increases. A vaccine (RhoGAM) may be given to the mother within three days of the first child’s birth to prevent her body from making antibodies that will attack any future Rh-positive fetuses in subsequent pregnancies (Aitken & Tichy, 2015). Also, babies affected by Rh incompatibility can be given blood transfusions before or right after birth (Fasano, 2017).

Environmental Hazards Many aspects of our modern industrial world can endanger the embryo or fetus. Some specific hazards to the embryo or fetus include radiation, toxic wastes, and other chemical pollutants (Jeong & others, 2018; Sreetharan & others, 2017).

X-ray radiation can affect the developing embryo or fetus, especially in the first several weeks after conception, when women do not yet know they are pregnant. Women and their physicians should weigh the risk of an X-ray when an actual or potential pregnancy is involved (Rajaraman & others, 2011). However, a routine diagnostic X-ray of a body area other than the abdomen, with the woman’s abdomen protected by a lead apron,Page 85 is generally considered safe (Brent, 2009, 2011).

Environmental pollutants and toxic wastes are also sources of danger to unborn children. Among the dangerous pollutants are carbon monoxide, mercury, and lead, as well as certain fertilizers and pesticides (Wang & others, 2017).

Maternal Diseases Maternal diseases and infections can produce defects in offspring by crossing the placental barrier, or they can cause damage during birth (Cuffe & others, 2017; Koren & Ornoy, 2018). Rubella (German measles) is one disease that can cause prenatal defects. A recent study found that cardiac defects, pulmonary problems, and microcephaly (a condition in which the baby’s head is significantly smaller and less developed than normal) were among the most common fetal and neonatal outcomes when pregnant women have rubella (Yazigi & others, 2017). Women who plan to have children should have a blood test before they become pregnant to determine whether they are immune to the disease.

Syphilis (a sexually transmitted infection) is more damaging later in prenatal development—four months or more after conception. Damage to offspring includes stillbirth, eye lesions (which can cause blindness), skin lesions, and congenital syphilis (Braccio, Sharland, & Ladhani, 2016). Penicillin is the only known treatment for syphilis during pregnancy (Moline & Smith, 2016).

Another infection that has received widespread attention is genital herpes. Newborns contract this virus when they are delivered through the birth canal of a mother with genital herpes (Sampath, Maduro, & Schillinger, 2017). About one-third of babies delivered through an infected birth canal die; another one-fourth become brain damaged. If an active case of genital herpes is detected in a pregnant woman close to her delivery date, a cesarean section can be performed (in which the infant is delivered through an incision in the mother’s abdomen) to keep the virus from infecting the newborn (Pinninti & Kimberlin, 2013).

AIDS is a sexually transmitted infection that is caused by the human immunodeficiency virus (HIV), which destroys the body’s immune system (Taylor & others, 2017). A mother can infect her offspring with HIV/AIDS in three ways: (1) during gestation across the placenta, (2) during delivery through contact with maternal blood or fluids, and (3) postpartum (after birth) through breast feeding. The transmission of AIDS through breast feeding is especially problematic in many developing countries (UNICEF, 2013). Babies born to HIV-infected mothers can be (1) infected and symptomatic (show HIV symptoms), (2) infected but asymptomatic (not show HIV symptoms), or (3) not infected at all. An infant who is infected and asymptomatic may still develop HIV symptoms through 15 months of age.

developmental connection

Conditions, Diseases, and Disorders

The greatest incidence of HIV/AIDS is in sub-Saharan Africa, where as many as 30 percent of mothers have HIV; many are unaware that they are infected with the virus. Connect to “Physical Development in Infancy.”

The more widespread disease of diabetes, characterized by high levels of sugar in the blood, also affects offspring (Briana & others, 2018; Haertle & others, 2017; Kaseva & others, 2018). A research review indicated that newborns with physical defects are more likely to have diabetic mothers (Eriksson, 2009). Women who have gestational diabetes also may deliver very large infants (weighing 10 pounds or more), and the infants are at risk for diabetes (Alberico & others, 2014) and cardiovascular disease (Amrithraj & others, 2017). One study found that 5- to 16-year-old Mexican American children were more likely to be obese if their mothers had gestational diabetes (women who have never had diabetes before but have high blood sugar levels during pregnancy) (Page & others, 2014). Also, a recent research review concluded that pregestational diabetes increases the risk of fetal heart disease (Pauliks, 2015).

Other Parental Factors So far we have discussed a number of drugs, environmental hazards, maternal diseases, and incompatible blood types that can harm the embryo or fetus. Here we will explore other characteristics of the mother and father that can affect prenatal and child development, including nutrition, age, and emotional states and stress.

Because the fetus depends entirely on its mother for nutrition, it is important for pregnant women to have good nutritional habits. In Kenya, this government clinic provides pregnant women with information about how their diet can influence the health of their fetus and offspring. What might the information about diet be like? ©Delphine Bousquet/AFP/Getty Images

Maternal Diet and Nutrition A developing embryo or fetus depends completely on its mother for nutrition, which comes from the mother’s blood (Kominiarek & Peaceman, 2017). The nutritional status of the embryo or fetus is determined byPage 86 the mother’s total caloric intake as well as her intake of proteins, vitamins, and minerals. Children born to malnourished mothers are more likely than other children to be malformed.

developmental connection

Conditions, Diseases, and Disorders

What are some key factors that influence whether individuals will become obese? Connect to “Physical and Cognitive Development in Early Adulthood.”

Maternal obesity adversely affects pregnancy outcomes through increased rates of hypertension, diabetes, respiratory complications, infections, and depression in the mother (Kumpulainen & others, 2018; Preston, Reynolds, & Pearson, 2018). A recent study revealed that at 14 weeks following conception fetuses of obese pregnant women had less efficient cardiovascular functioning (Ingul & others, 2016). An earlier study found that maternal overweight and obesity during pregnancy were associated with an increased risk of preterm birth, especially extremely preterm delivery (Cnattingius & others, 2013). Further, research indicates that maternal obesity during pregnancy is linked to cardiovascular disease and type 2 diabetes in the adolescent and adult offspring of these mothers (Agarwal & others, 2018; Slack & others, 2018). Research studies have found that maternal obesity is linked to an increase in stillbirth (Gardosi & others, 2013) and increased likelihood that the newborn will be placed in a neonatal intensive care unit (Minsart & others, 2013). Further, two recent research reviews concluded that maternal obesity during pregnancy is associated with an increased likelihood of offspring being obese in childhood and adulthood (Pinto Pereira & others, 2016; Santangeli, Sattar, & Huda, 2015). Management of obesity that includes weight loss and increased exercise prior to pregnancy is likely to benefit the mother and the baby (Dutton & others, 2018; Hanson & others, 2017). Limiting gestational weight gain to 11 to 20 pounds among pregnant women is likely to improve outcomes for the mother and the child (Simmons, 2011).

One aspect of maternal nutrition that is important for normal prenatal development is folic acid, a B-complex vitamin (Li & others, 2018; Viswanathan & others, 2017). A study of more than 34,000 women showed that taking folic acid either alone or as part of a multivitamin for at least one year prior to conceiving was linked with a 70 percent lower risk of delivering between 20 and 28 weeks and a 50 percent lower risk of delivering between 28 and 32 weeks (Bukowski & others, 2008). Also, as indicated earlier in the chapter, a lack of folic acid is related to neural tube defects in offspring, such as spina bifida (a defect in the spinal cord) (Li & others, 2018; Santos & others, 2016). And a recent research study in China found that folic acid supplementation during pregnancy reduced the risk of preterm birth (Liu & others, 2016). The U.S. Department of Health and Human Services (2018) recommends that pregnant women consume a minimum of 400 micrograms of folic acid per day (about twice the amount the average woman gets in one day). Orange juice and spinach are examples of foods rich in folic acid.

Eating fish is often recommended as part of a healthy diet, but pollution has made many fish a risky choice for pregnant women (Lipp & others, 2017). Some fish contain high levels of mercury, which is released into the air both naturally and by industrial pollution. When mercury falls into the water it can become toxic and accumulate in large fish, such as shark, swordfish, king mackerel, and some species of large tuna (American Pregnancy Association, 2018; Mayo Clinic, 2018). Mercury is easily transferred across the placenta, and the embryo’s developing brain and nervous system are highly sensitive to the metal. Researchers have found that prenatal mercury exposure is linked to adverse outcomes, including reduced placental and fetal growth, miscarriage, preterm birth, and lower intelligence (Jeong & others, 2017).

Recently, the American Pregnancy Association (2018) revised its conclusions about fish consumption during pregnancy but continued to recommend avoiding fish with a high mercury content, such as tilefish from the Gulf of Mexico, swordfish, shark, and king mackerel. The association and the FDA now recommend that pregnant women increase their consumption of fish that have a low mercury content, such as salmon, shrimp, tilapia, and cod.

Maternal Age When possible harmful effects on the fetus and infant are considered, two maternal age groups are of special interest: adolescents and women 35 years and older (Gockley & others, 2016; Kingsbury, Plotnikova, & Najman, 2018). The mortality rate of infants born to adolescent mothers is double that of infants born to mothers in their twenties. Adequate prenatal care decreases the probability that a child born to an adolescent girl will have physical problems. However, adolescents are the least likely of women in all age groups to obtain prenatal assistance from clinics and health services.

Maternal age is also linked to risk for adverse pregnancy outcomes. When a pregnant woman is older than 35, there is an increased risk that her child will have Down syndrome (Jaruratanasirikul & others, 2017). An individual with Down syndromehas distinctive facial characteristics, short limbs, intellectual disability, and motorPage 87 difficulties. A baby with Down syndrome rarely is born to a mother 16 to 34 years of age. However, when the mother reaches 40 years of age, the probability is slightly over 1 in 100 that a baby born to her will have Down syndrome, and by age 50 it is almost 1 in 10. When mothers are 35 years and older, risks also increase for low birth weight, preterm delivery, and fetal death (Koo & others, 2012; Mbugua Gitau & others, 2009). Also, in two recent studies, very advanced maternal age (40 years and older) was linked to adverse perinatal outcomes, including spontaneous abortion, preterm birth, stillbirth, and fetal growth restriction (Traisrisilp & Tongsong, 2015; Waldenstrom & others, 2015).

We still have much to learn about the influence of the mother’s age on risks of adverse outcomes during pregnancy and childbirth. As women remain active, exercise regularly, and are careful about their nutrition, their reproductive systems may remain healthier at older ages than was thought possible in the past.

What are some of the risks for infants born to adolescent mothers? ©Barbara Penoyar/Getty Images

Emotional States and Stress When a pregnant woman experiences intense fears, anxieties, and other emotions or negative mood states, physiological changes occur that may affect her fetus (Fatima, Srivastav, & Mondal, 2017). A mother’s stress may also influence the fetus indirectly by increasing the likelihood that the mother will engage in unhealthy behaviors such as taking drugs and receiving poor prenatal care.

High maternal anxiety and stress during pregnancy can have long-term consequences for the offspring (Isgut & others, 2017; Pinto & others, 2017). One study found that high levels of depression, anxiety, and stress during pregnancy were linked to internalizing problems in adolescence (Betts & others, 2014). A research review indicated that pregnant women with high levels of stress are at increased risk for having a child with emotional or cognitive problems, attention deficit hyperactivity disorder (ADHD), and language delay (Taige & others, 2007). Maternal emotions and stress also can influence the fetus indirectly by increasing the likelihood that the mother will engage in unhealthy behaviors such as taking drugs and receiving inadequate prenatal care. Further, a recent research review concluded that regardless of the form of maternal prenatal stress or anxiety and the prenatal trimester in which the stress or anxiety occurred, during the first two years of life their offspring displayed lower levels of self-regulation (Korja & others, 2017).

Maternal depression can have an adverse effect on birth outcomes and children’s development (Park & others, 2018). A research review concluded that maternal depression during pregnancy is linked to preterm birth (Mparmpakas & others, 2013), and another study linked maternal depression during pregnancy to low birth weight in full-term offspring (Chang & others, 2014). Another study revealed that maternal depression during pregnancy was related to increased risk for depression in offspring at age 18 (Pearson & others, 2013). Also, a recent study found that taking antidepressants early in pregnancy was linked to an increased risk of miscarriage (Almeida & others, 2016). In another study, when fetuses was exposed to serotonin-based antidepressants, they were more likely to be born preterm (Podrebarac & others, 2017). Further, a recent study revealed that taking antidepressants in the second or third trimesters of pregnancy was linked to an increased risk of autism spectrum disorders in children (Boukhris & others, 2016).

Paternal Factors So far, we have discussed how characteristics of the mother—such as drug use, disease, diet and nutrition, age, and emotional states—can influence prenatal development and the development of the child. Might there also be some paternal risk factors? Indeed, there are several (Sigman, 2017). Men’s exposure to lead, radiation, certain pesticides, and petrochemicals may cause abnormalities in sperm that lead to miscarriage or to diseases such as childhood cancer (Cordier, 2008). The father’s smoking during the mother’s pregnancy also can cause problems for the offspring (Han & others, 2015). A recent research review concluded that tobacco smoking is linked to impaired male fertility, as well as increased DNA damage, aneuploidy (abnormal number of chromosomes in a cell), and mutations in sperm (Beal, Yauk, & Marchetti, 2017). Also, in one study, heavy paternal smoking was associated with the risk of early pregnancy loss (Venners & others, 2004). This negative outcome may be related to the effects of secondhand smoke. And in another study, paternal smoking around the time of the child’s conception was linked to an increased risk of the child developing leukemia (Milne & others, 2012). Researchers have found that increasingPage 88 paternal age decreases the success rate of in vitro fertilization and increases the risk of preterm birth (Sharma & others, 2015). Also, a research review concluded that there is an increased risk of spontaneous abortion, autism, and schizophrenic disorders when the father is 40 years of age or older (Reproductive Endocrinology and Infertility Committee & others, 2012). A research study revealed that children born to fathers who were 40 years of age or older had increased risk of developing autism because of higher rates of random gene mutations in the older fathers (Kong & others, 2012). However, the age of the mother was not linked to development of autism in children.

How do pregnant women’s emotional states and stress levels affect prenatal development and birth? ©skynesher/Getty Images

Another way that the father can influence prenatal and birth outcomes is through his relationship with the mother. By being supportive, helping with chores, and having a positive attitude toward the pregnancy, the father can improve the physical and psychological well-being of the mother. Conversely, a conflictual relationship with the mother is likely to bring adverse outcomes (Molgora & others, 2018). For example, a recent study found that intimate partner violence increased the mother’s stress level (Fonseca-Machado Mde & others, 2015).

In a study in China, the longer fathers smoked, the greater the risk that their children would develop cancer (Ji & others, 1997). What are some other paternal factors that can influence the development of the fetus and the child? ©Ryan Pyle/Corbis/Getty Images

PRENATAL CARE

Although prenatal care varies enormously, it usually involves a defined schedule of visits for medical care, which typically includes screening for manageable conditions and treatable diseases that can affect the baby or the mother (Flanagan & others, 2018; Goldenberg & McClure, 2018; Jarris & others, 2017; Sheeder & Weber Yorga, 2017). In addition to medical care, prenatal programs often include comprehensive educational, social, and nutritional services (Yeo, Crandell, & Jones-Vessey, 2016).

An increasing number of studies are finding that exercise either benefits the mother’s health and has positive neonatal outcomes or that there are no differences in outcomes (Barakat & others, 2017; Huang & others, 2017). Exercise during pregnancy helps prevent constipation, conditions the body, reduces the likelihood of excessive weight gain, lowers the risk of developing hypertension, improves immune system functioning, and is associated with a more positive mental state, including reduced levels of stress and depression (Bacchi & others, 2017; Barakat & others, 2016; Magro-Malosso & others, 2017; Marques & others, 2015). For example, a recent study found that two weekly 70-minute yoga sessions reduced pregnant women’s stress and enhanced their immune system functioning (Chen & others, 2017).

Exercise during pregnancy can also have positive benefits for offspring. For example, a recent study revealed that regular exercise by pregnant women was linked to more advanced development of the neonatal brain (Laborte-Lemoyne, Currier, & Ellenberg, 2017).

Does prenatal care matter? Information about pregnancy, labor, delivery, and caring for the newborn can be especially valuable for first-time mothers (Liu & others, 2017; Yun & others, 2014). Prenatal care is also very important for women in poverty and immigrant women because it links them with other social services (Gabbe & others, 2018; Kim & others, 2018; Mazul, Salm Ward, & Ngui, 2017).

How might a woman’s exercise during pregnancy benefit her and her offspring? ©Tracy Frankel/The Image Bank/Getty Images

An innovative program that is rapidly expanding in the United States is CenteringPregnancy (Chae & others, 2017; Heberlein & others, 2016; Liu & others, 2017). This program is relationship-centered and provides complete prenatal care in a group setting. CenteringPregnancy replaces traditional 15-minute physician visits with 90-minute peer group support settings and self-examination led by a physician or certified nurse-midwife. Groups of up to 10 women (and often their partners) meet regularly beginning at 12 to 16 weeks of pregnancy. The sessions emphasize empowering women to play an active role in experiencing a positive pregnancy. One study revealed that CenteringPregnancy groups made more prenatal visits, had higher breast feeding rates, and were more satisfied with their prenatal care than women in individual care (Klima & others, 2009). In a research review, participation in CenteringPregnancy increased breast feeding initiation by 53 percent overall and by 71 percent in African American womenPage 89 (Robinson, Garnier-Villarreal, & Hanson, 2018). Also, a recent study of adolescent mothers revealed that CenteringPregnancy was successful in getting participants to attend meetings, have appropriate weight gain, increase the use of highly effective contraceptive methods, and increase breast feeding (Trotman & others, 2015). And research has revealed that CenteringPregnancy group prenatal care is associated with reduced rates of preterm birth (Novick & others, 2013), as well as reduced rates of low birth weight and placement in a neonatal intensive care unit (Crockett & others, 2017; Gareau & others, 2016).

NORMAL PRENATAL DEVELOPMENT

Much of our discussion so far in this chapter has focused on what can go wrong with prenatal development. Prospective parents should take steps to avoid the vulnerabilities to fetal development that we have described. But it is important to keep in mind that most of the time, prenatal development does not go awry, and development occurs along the positive path that we described at the beginning of the chapter.

The increasingly popular CenteringPregnancy program alters routine prenatal care by bringing women out of exam rooms and into relationship-oriented groups. ©MBI/Alamy Stock Photo

Review Connect Reflect

LG1 Describe prenatal development.

Review

· What is the course of prenatal development?

· What is teratology, and what are some of the main threats to prenatal development?

· What are some good prenatal care strategies?

· Why is it important to take a positive approach to prenatal development?

Connect

· We have discussed chromosomal and gene-linked abnormalities that can affect prenatal development. How are the symptoms of the related conditions or risks similar to or different from those caused by teratogens or other hazards?

Reflect Your Own Personal Journey of Life

· If you are a woman, imagine that you have just found out that you are pregnant. What health-enhancing strategies will you follow during the prenatal period? If you are not a woman, imagine that you are the partner of a woman who has just found out she is pregnant. What will be your role in increasing the likelihood that the prenatal period will go smoothly?

2 Birth

LG2 Describe the birth process.

The Birth Process

Assessing the Newborn

Preterm and Low Birth Weight Infants

Nature writes the basic script for how birth occurs, but parents make important choices about conditions surrounding birth. We look first at the sequence of physical stages that occur when a child is born.

There was a star danced, and under that I was born.

—William Shakespeare

English Playwright, 17th Century

THE BIRTH PROCESS

The birth process occurs in stages, takes place in different contexts, and in most cases involves one or more attendants.

Stages of Birth The birth process occurs in three stages. The first stage is the longest of the three. Uterine contractions are 15 to 20 minutes apart at the beginning and last up to a minute. These contractions cause the woman’s cervix to stretch and open. As the first stage progresses, the contractions come closer togetherPage 90, appearing every two to five minutes. Their intensity increases. By the end of the first birth stage, contractions dilate the cervix to an opening of about 10 centimeters (4 inches), so that the baby can move from the uterus to the birth canal. For a woman having her first child, the first stage lasts an average of 6 to 12 hours; for subsequent children, this stage typically is much shorter.

After the long journey of prenatal development, birth takes place. During birth the baby is on a threshold between two worlds. What is the fetus/newborn transition like? ©ERproductions Ltd/Getty Images

The second birth stage begins when the baby’s head starts to move through the cervix and the birth canal. It terminates when the baby completely emerges from the mother’s body. With each contraction, the mother bears down hard to push the baby out of her body. By the time the baby’s head is out of the mother’s body, the contractions come almost every minute and last for about a minute. This stage typically lasts approximately 45 minutes to an hour.

Afterbirth is the third stage, at which time the placenta, umbilical cord, and other membranes are detached and expelled. This final stage is the shortest of the three birth stages, lasting only minutes.

Childbirth Setting and Attendants In 2015 in the United States, 98.5 percent of births took place in hospitals (Martin & others, 2017). Of the 1.5 percent of births occurring outside of a hospital, 63 percent took place in homes and almost 31 percent in free-standing birthing centers. The percentage of U.S. births at home is the highest since reporting of this context began in 1989. This increase in home births has occurred mainly among non-Latino White women, especially those who were older and married. For these non-Latino White women, two-thirds of their home births are attended by a midwife.

The people who help a mother during birth vary across cultures. In U.S. hospitals, it has become the norm for fathers or birth coaches to remain with the mother throughout labor and delivery. In the East African Nigoni culture, men are completely excluded from the childbirth process. When a woman is ready to give birth, female relatives move into the woman’s hut and the husband leaves, taking his belongings (clothes, tools, weapons, and so on) with him. He is not permitted to return until after the baby is born. In some cultures, childbirth is an open, community affair. For example, in the Pukapukan culture in the Pacific Islands, women give birth in a shelter that is open for villagers to observe.

In India, a midwife checks on the size, position, and heartbeat of a fetus. Midwives deliver babies in many countries around the world. What are some cultural variations in prenatal care? ©Viviane Moos/Corbis/Getty Images

Midwives Midwifery is a profession that provides health care to women during pregnancy, birth, and the postpartum period (Christensen & Overgaard, 2017; Cohen, Sumersille, & Friedman, 2018; Faucher, 2018). Midwives also may give women information about reproductive health and annual gynecological examinations. They may refer women to general practitioners or obstetricians if a pregnant woman needs medical care beyond a midwife’s expertise and skill.

Midwifery is practiced in most countries throughout the world (Arabi & others, 2018; Miyake & others, 2017). In Holland, more than 40 percent of babies are delivered by midwives rather than doctors. However, in the United States, recently only 8 percent of all hospital births in the United States were attended by a midwife (Martin & others, 2017). Nonetheless, the 8 percent figure represents a substantial increase from less than 1 percent in 1975. A research review concluded that for low-risk women, midwife-led care was characterized by a reduction in procedures during labor and increased satisfaction with care (Sutcliffe & others, 2012). Also, in this study no adverse outcomes were found for midwife-led care compared with physician-led care.

Doulas In some countries, a doula attends a childbearing woman. Doula is a Greek word that means “a woman who helps.” A doula is a caregiver who provides continuous physical, emotional, and educational support for the mother before, during, and after childbirth (McLeish & Redshaw, 2018). Doulas remain with the parents throughout labor, assessing and responding to the mother’s needs. Researchers have found positive effects when a doula is present at the birth of a child (Wilson & others, 2017). One study found that doula-assisted mothers were four times less likely to have a low birth weight baby and two times less likely to have experienced a birth complication involving themselves or their babyPage 91 (Gruber, Cupito, & Dobson, 2013). Another study revealed that for Medicaid recipients the odds of having a cesarean delivery were 41 percent lower for doula-supported births in the United States (Kozhimmanil & others, 2013). Thus, increasing doula-supported births could substantially lower the cost of a birth by reducing cesarean rates.

In the United States, most doulas work as independent providers hired by the expectant parents. Doulas typically function as part of a “birthing team,” serving as an adjunct to the midwife or the hospital’s obstetrical staff.

Methods of Childbirth U.S. hospitals often allow the mother and her obstetrician a range of options regarding the method of delivery. Key choices involve the use of medication, whether to use any of a number of nonmedicated techniques to reduce pain, and when to have a cesarean delivery.

Medication Three basic kinds of drugs that are used for labor are analgesia, anesthesia, and oxytocin/Pitocin.

Analgesia is used to relieve pain. Analgesics include tranquilizers, barbiturates, and narcotics (such as Demerol).

Anesthesia is used in late first-stage labor and during delivery to block sensation in an area of the body or to block consciousness. There is a trend toward not using general anesthesia, which blocks consciousness, in normal births because general anesthesia can be transmitted through the placenta to the fetus (Edwards & Jackson, 2017). An epidural block is regional anesthesia that numbs the woman’s body from the waist down. A research review concluded that epidural analgesia provides effective pain relief but increases the likelihood of having to use instruments during vaginal birth (Jones & others, 2012). Researchers are continuing to explore safer drug mixtures for use at lower doses to improve the effectiveness and safety of epidural anesthesia (Kobayashi & others, 2017; Wilson & others, 2018).

Oxytocin is a hormone that promotes uterine contractions; a synthetic form called Pitocin® is widely used to decrease the duration of the first stage of labor. The relative benefits and risks of administering synthetic forms of oxytocin during childbirth continue to be debated (Carlson, Corwin, & Lowe, 2017).

Predicting how a drug will affect an individual woman and her fetus is difficult (Ansari & others, 2016). A particular drug might have only a minimal effect on one fetus yet have a much stronger effect on another. The drug’s dosage also is a factor (Rankin, 2017). Stronger doses of tranquilizers and narcotics given to decrease the mother’s pain potentially have a more negative effect on the fetus than mild doses. It is important for the mother to assess her level of pain and have a voice in deciding whether she receives medication.

Natural and Prepared Childbirth For a brief time not long ago, the idea of avoiding all medication during childbirth gained favor in the United States. Instead, many women chose to reduce the pain of childbirth through techniques known as natural childbirth and prepared childbirth. Today, at least some medication is used in the typical childbirth, but elements of natural childbirth and prepared childbirth remain popular (Skowronski, 2015).

Natural childbirth is the method that aims to reduce the mother’s pain by decreasing her fear by providing information about childbirth and teaching her and her partner to use breathing methods and relaxation techniques during delivery (Bacon & Tomich, 2017; London & others, 2017). One type of natural childbirth that is used today is the Bradley Method, which involves husbands as coaches, relaxation for easier birth, and prenatal nutrition and exercise.

French obstetrician Ferdinand Lamaze developed a method similar to natural childbirth that is known as prepared childbirth , or the Lamaze method. It includes a special breathing technique to control pushing in the final stages of labor, as well as more detailed education about anatomy and physiology. The Lamaze method has become very popular in the United States (Podgurski, 2016). The pregnant woman’s partner usually serves as a coach who attends childbirth classes with her and helps with her breathing and relaxation during delivery.

Page 92

connecting with careers

Linda Pugh, Perinatal Nurse

Perinatal nurses work with childbearing women to support health and growth during the childbearing experience. Linda Pugh, Ph.D., R.N.C., is a perinatal nurse on the faculty at The Johns Hopkins University School of Nursing. She is certified as an inpatient obstetric nurse and specializes in the care of women during labor and delivery. She teaches undergraduate and graduate students, educates professional nurses, and conducts research. In addition, Pugh consults with hospitals and organizations about women’s health issues and topics we discuss in this chapter. Her research interests include nursing interventions with low-income breast-feeding women, ways to prevent and ameliorate fatigue during childbearing, and the use of breathing exercises during labor.

Courtesy of Linda Pugh

In sum, proponents of current natural and prepared childbirth methods conclude that when information and support are provided, women know how to give birth. To read about one nurse whose research focuses on fatigue during childbearing and breathing exercises during labor, see the Connecting with Careers profile. And to read about the wide variety of techniques now being used to reduce stress and control pain during labor, see Connecting Development to Life .

Cesarean Delivery In a cesarean delivery , the baby is removed from the mother’s uterus through an incision made in her abdomen. Cesarean deliveries are performed if the baby is lying crosswise in the uterus, if the baby’s head is too large to pass through the mother’s pelvis, if the baby develops complications, or if the mother is bleeding vaginally. Because of increased rates of respiratory complications, elective cesarean delivery is not recommended prior to 39 weeks of gestation unless there is an indication of fetal lung maturity (Greene, 2009). The benefits and risks of cesarean deliveries continue to be debated in the United States and around the world (Kupari & others, 2016; Ladewig, London, & Davidson, 2017). Some critics believe that too many babies are delivered by cesarean section in the United States (Blakey, 2011). The World Health Organization states that a country’s cesarean section rate should be 10 percent or less. The U.S. cesarean birth rate in 2015 was 32 percent, the lowest rate since 2007 (Martin & others, 2017). The highest cesarean rates are in the Dominican Republic and Brazil (56 percent); the lowest in New Zealand and the Czech Republic (26 percent) (McCullogh, 2016).

What are some of the specific reasons why physicians do a cesarean delivery? The most common reasons are failure to progress through labor (hindered by epidurals, for example) and fetal distress. Normally, the baby’s head comes through the vagina first. But if the baby is in a breech position , the baby’s buttocks are the first part to emerge from the vagina. In 1 of every 25 deliveries, the baby’s head is still in the uterus when the rest of the body is out. Breech births can cause respiratory problems. As a result, if the baby is in a breech position, a cesarean delivery is usually performed (Glavind & Uldbjerg, 2015).

ASSESSING THE NEWBORN

Almost immediately after birth, after the baby and its parents have been introduced, a newborn is taken to be weighed, cleaned up, and tested for signs of developmental problems that might require urgent attention. The Apgar Scale is widely used to assess the health of newborns at one and five minutes after birth. The Apgar Scale evaluates an infant’s heart rate, respiratory effort, muscle tone, body color, and reflex irritability. An obstetrician or a nurse does the evaluation and gives the newborn a score, or reading, of 0, 1, or 2 on each of these five health signs (see Figure 6). A total score of 7 to 10 indicates that the newborn’s condition is good. A score of 5 indicates there may be developmental difficulties. A score of 3 or below signals an emergency and indicates that the baby might not survive.

FIGURE 6 The Apgar Scale. A newborn’s score on the Apgar Scale indicates whether the baby has urgent medical problems. What are some trends in the Apgar scores of U.S. babies? Source: Apgar, Virginia, “The Apgar Scale,” A Proposal for a New Method of Evaluation of the Newborn Infant, from Anesthesia and Analgesia, vol 32. New York: Lippincott, Williams & Wilkins, 1953.Page 93

connecting development to life

From Waterbirth to Music Therapy

The effort to reduce stress and control pain during labor has recently led to an increased use of older and newer nonmedicated techniques (Bindler & others, 2017; Cooper, Warland, & McCutcheon, 2018; Lewis & others, 2018a, b). These include waterbirth, massage, acupuncture, hypnosis, and music therapy.

What characterizes the use of waterbirth in delivering a baby? Courtesy of Dr. Holly Beckwith

Waterbirth

Waterbirth involves giving birth in a tub of warm water. Some women go through labor in the water and get out for delivery; others remain in the water for delivery. The rationale for waterbirth is that the baby has been in an amniotic sac for many months and that delivery in a similar environment is likely to be less stressful for the baby and the mother (Kavosi & others, 2015). Mothers get into the warm water when contractions become closer together and more intense. Getting into the water too soon can cause labor to slow or stop. An increasing number of studies either show no differences in neonatal and maternal outcomes for waterbirth and non-waterbirth deliveries or positive outcomes for waterbirth (Davies & others, 2015; Taylor & others, 2016). For example, in a recent Swedish study, women who gave birth in water had a lower risk of vaginal tears, made quicker progress through the second stage of labor, needed fewer drugs for pain relief and interventions for medical problems, and rated their birth experience more positively than women who had conventional spontaneous vaginal births (Ulfsdottir, Saltvedt, & Georgsson, 2018). Waterbirth has been practiced more often in European countries such as Switzerland and Sweden in recent decades than in the United States but is increasingly being included in U.S. birth plans.

Massage

Massage is increasingly used prior to and during delivery (Frawley & others, 2016; Withers, Kharazmi, & Lim, 2018). Researchers have found that massage therapy reduces pain during labor (Gallo & others, 2018; Jones & others, 2012; Shahoei & others, 2017). For example, a recent study found that lower back massage reduced women’s labor pain and increased their satisfaction with the birth experience (Unalmis Erdogan, Yanikkerem, & Goker, 2018).

Acupuncture

Acupuncture, the insertion of very fine needles into specific locations in the body, is used as a standard procedure to reduce the pain of childbirth in China, although it only recently has begun to be used in the United States for this purpose (Jo & Lee, 2018; Mollart & others, 2018). Recent research indicates that acupuncture can have positive effects on labor and delivery (Akbarzadeh & others, 2015; Smith, Armour, & Ee, 2016). For example, in a recent study acupuncture was successful in reducing labor pain 30 minutes after the intervention (Allameh, Tehrani, & Ghasemi, 2015).

Hypnosis

Hypnosis, the induction of a psychological state of altered attention and awareness in which the individual is unusually responsive to suggestions, is also increasingly being used during childbirth (Howell, 2014; Mollart & others, 2018). Some studies have indicated positive effects of hypnosis for reducing pain during childbirth (Madden & others, 2016; McAllister & others, 2017).

Music Therapy

Music therapy during childbirth, which involves the use of music to reduce stress and manage pain, is becoming more common (Dehcheshmeh & Rafiel, 2015). More research is needed to determine its effectiveness (Laopaiboon & others, 2009).

What are some reasons that natural childbirth methods such as these might be chosen instead of medication?

The Apgar Scale is especially good at assessing the newborn’s ability to cope with the stress of delivery and the demands of a new environment (London & others, 2017). It also identifies high-risk infants who need resuscitation. One study revealed that compared with children who have a high Apgar score (9 to 10), the risk of developing attention deficit hyperactivityPage 94disorder (ADHD) in childhood was 75 percent higher for newborns with a low Apgar score (1 to 4) and 63 percent higher for newborns with an Apgar score of 5 to 6 (Li, Olsen, & others, 2011). Recent studies have found that low Apgar scores are associated with long-term needs for additional support in education and decreased educational attainment (Tweed & others, 2016), increased risk of developmental vulnerability at 5 years of age (Razaz & others, 2016), and increased risk for developing ADHD (Hanc & others, 2016).

Another assessment of the newborn is the Brazelton Neonatal Behavioral Assessment Scale (NBAS) , which is typically performed within 24 to 36 hours after birth. It is also used as a sensitive index of neurological competence up to one month after birth for typical infants and as a measure in many studies of infant development (Braithwaite & others, 2017). The NBAS assesses the newborn’s neurological development, reflexes, and reactions to people and objects.

A “kilogram kid,” weighing less than 2.3 pounds at birth. What are some long-term outcomes for weighing so little at birth? ©Diether Endlicher/AP Images

The NBAS is designed to assess normal, healthy, full-term infants. An “offspring” of the NBAS, the Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS) provides another assessment of the newborn’s behavior, neurological and stress responses, and regulatory capacities (Aubuchon-Endsley & others, 2017; Spittle & others, 2017). The NBAS is especially designed to assess at-risk infants.

PRETERM AND LOW BIRTH WEIGHT INFANTS

Various conditions that pose threats for newborns have been given different labels. We will examine these conditions and discuss interventions for improving outcomes of preterm infants.

Preterm and Small for Date Infants Three related conditions pose threats to many newborns: low birth weight, being born preterm, and being small for date:

· Low birth weight infants weigh less than 5 pounds 8 ounces at birth. Very low birth weight newborns weigh less than 3 pounds 4 ounces, and extremely low birth weight newborns weigh less than 2 pounds.

· Preterm infants are those born three weeks or more before the pregnancy has reached its full term—in other words, before the completion of 37 weeks of gestation (the time between fertilization and birth).

· Small for date infants (also called small for gestational age infants) are those whose birth weight is below normal when the length of the pregnancy is considered. They weigh less than 90 percent of all babies of the same gestational age. Small for date infants may be preterm or full term. One study found that small for date infants had more than a fourfold increased risk of death (Regev & others, 2003).

In 2015, 9.6 percent of babies born in the United States werePage 95 born preterm (Martin & others, 2017). The preterm birth rate was 8.8 percent for non-Latino White infants, down from 11.4 percent in 2011 (Martin & others, 2017). In 2015, the preterm birth rate was 13.4 percent for African American infants (down from 16.7 percent in 2011) and 9.1 percent for Latino infants (down from 11.6 percent in 2011) (Martin & others, 2017).

Recently, considerable attention has been directed to the role that progestin (a synthetic hormone similar to progesterone) might play in reducing preterm births (Awwad & others, 2015; Iams & others, 2018). One study found that progestin treatment was associated with a decrease in preterm birth for women with a history of one or more spontaneous births (Markham & others, 2014). Increasing use of progestin and decreasing rates of smoking are among the factors that likely account for the recent decrease in preterm births (Schoen & others, 2015).

Might exercise during pregnancy reduce the likelihood of preterm birth? One study found that compared with sedentary pregnant women, women who engaged in light leisure time physical activity had a 24 percent reduced likelihood of preterm delivery and those who participated in moderate to heavy leisure time physical activity had a 66 percent reduced risk of preterm delivery (Hegaard & others, 2008).

The incidence of low birth weight varies considerably from country to country. In some countries, such as India and Sudan, where poverty is rampant and the health and nutrition of mothers are poor, the percentage of low birth weight babies reaches as high as 31 percent (see Figure 7). In the United States, there has been an increase in low birth weight infants in the last two decades, and the U.S. low birth weight rate of 9.6 percent in 2015 is considerably higher than that of many other developed countries (Martin & others, 2017). For example, only 4 percent of the infants born in Sweden, Finland, Norway, and South Korea are low birth weight, and only 5 percent of those born in New Zealand, Australia, and France are low birth weight.

FIGURE 7 Percentage of Infants Born with Low Birth Weight in Selected Countries

In both developed and developing countries, adolescents who give birth when their bodies have not fully matured are at risk for having low birth weight babies (Bird & others, 2017; Kirbas, Gulerman, & Daglar, 2016). In the United States, the increase in the number of low birth weight infants is due to factors such as drug use, poor nutrition, multiple births, reproductive technologies, and improved technology and prenatal care that result in more high-risk babies surviving (National Center for Health Statistics, 2012; Pereira & others, 2017). Poverty also continues to be a major factor in preterm births in the United States (Huynh & others, 2017; Wallace & others, 2016). Women living in poverty are more likely to be obese, have diabetes and hypertension, and to smoke cigarettes and use illicit drugs, and less likely to receive regular prenatal care (Timmermans & others, 2011).

developmental connection

Poverty

Poverty continues to negatively affect development throughout childhood. Connect to “Socioemotional Development in Early Childhood” and “Socioemotional Development in Middle and Late Childhood.”

Consequences of Preterm Birth and Low Birth Weight Although most preterm and low birth weight infants are healthy, as a group they have more health problems and developmental delays than normal birth weight infants (George & others, 2018; London & others, 2017). For preterm birth, the terms extremely preterm and very preterm are increasingly used (Ohlin & others, 2015). Extremely preterm infants are those born at less than 28 weeks gestation, and very preterm infants are those born at less than 33 weeks of gestational age. Figure 8 shows the results of a Norwegian study indicating that the earlier preterm infants are born, the more likely they are to drop out of school (Swamy, Ostbye, & Skjaerven, 2008).

FIGURE 8 Percentage of Preterm and Full-Term Infants Who Dropped Out of School

The number and severity of health problems increase when infants are born very early and as their birth weight decreases (Linsell & others, 2017; Pascal & others, 2018). Survival rates for infants who are born very early and very small have risen, but with this improved survival rate have come an increased rate of severe brain damage (Rogers & Hintz, 2018) and lower level of executive function, especially in working memory and planning (Burnett & others, 2018).

One study revealed that very preterm, low birth weight infants had abnormal axon development in their brains and impaired cognitive development at 9 years of age (Iwata & others, 2012). Children born low in birth weight are more likely than their normal birth weight counterparts to develop a learning disability, attention deficit hyperactivity disorder, autism spectrum disorders, or breathing problems such as asthma (Brinskma & others, 2017; Ng & others, 2017). Approximately 50 percent of all low birth weight children are enrolled in special education programs.

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Nurturing Low Birth Weight and Preterm Infants Two increasingly used interventions in the neonatal intensive care unit (NICU) are kangaroo care and massage therapy. Kangaroo care involves skin-to-skin contact in which the baby, wearing only a diaper, is held upright against the parent’s bare chest, much as a baby kangaroo is carried by its mother (Raajashri & others, 2018; Stockwell, 2017). Kangaroo care is typically practiced for two to three hours per day, skin-to-skin over an extended time in early infancy.

Why use kangaroo care with preterm infants? Preterm infants often have difficulty coordinating their breathing and heart rate, and the close physical contact with the parent provided by kangaroo care can help to stabilize the preterm infant’s heartbeat, temperature, and breathing (Boundy & others, 2017; Furman, 2017). Preterm infants who experience kangaroo care gain more weight than their counterparts who are not given this care (Sharma, Murki, & Oleti, 2018). Recent research also revealed that kangaroo care decreased pain in newborns (Johnston & others, 2017; Mooney-Leber & Brummelte, 2017). Further, a research review concluded that kangaroo care decreased the risk of mortality in low birth weight infants (Conde-Aguedelo, Belizan, & Diaz-Rossello, 2014). Also, a research study demonstrated the positive long-term benefits of kangaroo care (Feldman, Rosenthal, & Eidelman, 2014). In this study, maternal-newborn kangaroo care with preterm infants was linked to better respiratory and cardiovascular functioning, sleep patterns, and cognitive functioning from 6 months to 10 years of age. Further, in a longitudinal study, the nurturing positive effects of kangaroo care with preterm and low birth weight infants that were initially found for intelligence and home environment at one year of age were still positive 20 years later in emerging adults’ reduced school absenteeism, reduced hyperactivity, lower aggressiveness, and social skills (Charpak & others, 2017).

A survey conducted in the United States found that mothers were much more likely to have a positive view of kangaroo care and to believe it should be provided daily than were neonatal intensive care nurses (Hendricks-Munoz & others, 2013). There is concern that kangaroo care is not used as often as it could be used in neonatal intensive care units (Smith & others, 2017). Increasingly, kangaroo care is recommended as standard practice for all newborns (Johnston & others, 2017).

developmental connection

Attachment

A classic study with surrogate cloth and wire monkeys demonstrated the important role that touch plays in infant attachment. Connect to “Socioemotional Development in Infancy.”

Many adults will attest to the therapeutic effects of receiving a massage. In fact, many will pay a premium to receive one at a spa on a regular basis. But can massage play a role in improving the developmental outcomes for preterm infants? A study found that both kangaroo care and massage therapy were equally effective in improving body weight and reducing length of hospital stay for low birth weight infants (Rangey & Sheth, 2014). In another recent study, massage therapy improved the scores of HIV-exposed infants on both physical and mental scales, while also improving their hearing and speech (Perez & others, 2015). To read more about massage therapy, see Connecting Through Research .

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Review Connect Reflect

LG2 Describe the birth process.

Review

· What are the three main stages of birth? What are some examples of birth strategies? What is the transition from fetus to newborn like for the infant?

· What are three measures of neonatal health and responsiveness?

· What are the outcomes for children if they are born preterm or with a low birth weight?

Connect

· What correlations have been found between birth weight and country of birth, and what might the causes be?

Reflect Your Own Personal Journey of Life

· If you are a female, which birth strategy do you prefer? Why? If you are a male, how involved would you want to be in helping your partner during the birth of your baby? Explain.

connecting through research

How Does Massage Therapy Affect the Mood and Behavior of Babies?

Throughout history and in many cultures, caregivers have massaged infants. In Africa and Asia, infants are routinely massaged by parents or other family members for several months after birth. In the United States, interest in using touch and massage to improve the growth, health, and well-being of infants has been stimulated by the research of Tiffany Field, director of the Touch Research Institute at the University of Miami School of Medicine (Field, 2001, 2007, 2010b, 2017; Diego, Field, & Hernandez-Reif, 2008, 2014; Field, Diego, & Hernandez-Reif, 2008, 2010; Field & others, 2006).

In one study, preterm infants in a neonatal intensive care unit (NICU) were randomly assigned to a massage therapy group or a control group (Hernandez-Reif, Diego, & Field, 2007). For five consecutive days, the preterm infants in the massage group were given three 15-minute moderate-pressure massages. Behavioral observations of the following stress behaviors were made on the first and last days of the study: crying, grimacing, yawning, sneezing, jerky arm and leg movements, startles, and finger flaring. The various stress behaviors were summarized in a composite stress behavior index. As indicated in Figure 9 , massage had a stress-reducing effect on the preterm infants, which is especially important because they encounter numerous stressors while they are hospitalized.

Tiffany Field massages a newborn infant. What types of infants have benefited from massage therapy? Courtesy of Dr. Tiffany Field

In a research review of massage therapy with preterm infants, Field and her colleagues (Field, Hernandez-Reif, & Freedman, 2004) concluded that the most consistent findings involve two positive results: (1) increased weight gain and (2) discharge from the hospital from three to six days earlier.

FIGURE 9 Preterm Infants Show Reduced Stress Behaviors and Activity After Five Days of Massage Therapy Source: Hernandez-Reif, M., Diego, M., & Field, T. “Preterm infants show reduced stress behaviors and activity after 5 days of massage therapy,” Infant Behavior and Development, 30, 2007, 557–561.

Infants are not the only ones who may benefit from massage therapy (Field, 2017). In other studies, Field and her colleagues have demonstrated the benefits of massage therapy with women in reducing labor pain (Field, Hernandez-Reif, Taylor, & others, 1997), with children who have asthma (Field, Henteleff, & others, 1998), with autistic children’s attentiveness (Field, Lasko, & others, 1997), and with adolescents who have attention deficit hyperactivity disorder (Field, Quintino, & others, 1998).

3 The Postpartum Period

LG3 Explain the changes that take place in the postpartum period.

Physical Adjustments

Emotional and Psychological Adjustments

Bonding

The weeks after childbirth present challenges for many new parents and their offspring. This is the postpartum period , the period after childbirth or delivery that lasts for about six weeks or until the mother’s body has completed its adjustment and has returned to a nearly prepregnant state. It is a time when the woman adjusts, both physicallyPage 98 and psychologically, to the process of childbearing.

The postpartum period involves a great deal of adjustment and adaptation (Doering & others, 2017). The adjustments needed are physical, emotional, and psychological.

PHYSICAL ADJUSTMENTS

A woman’s body makes numerous physical adjustments in the first days and weeks after childbirth (Neiterman & Fox, 2018). She may have a great deal of energy or feel exhausted and let down. Though these changes are normal, the fatigue can undermine the new mother’s sense of well-being and confidence in her ability to cope with a new baby and a new family life (Doering, Sims, & Miller, 2017).

A concern is the loss of sleep that the primary caregiver experiences in the postpartum period (McBean, Kinsey, & Montgomery-Downs, 2016). In the 2007 Sleep in America survey, a substantial percentage of women reported loss of sleep during pregnancy and in the postpartum period (National Sleep Foundation, 2007) (see Figure 10). The loss of sleep can contribute to stress, marital conflict, and impaired decision making (Meerlo, Sgoifo, & Suchecki, 2008). In a recent study, worsening or minimal improvement in sleep problems from 6 weeks to 7 months postpartum were associated with an increase in depressive symptoms (Lewis & others, 2018).

FIGURE 10 Sleep Deprivation in Pregnant and Postpartum Women

After delivery, a mother’s body undergoes sudden and dramatic changes in hormone production. When the placenta is delivered, estrogen and progesterone levels drop steeply and remain low until the ovaries start producing hormones again.

EMOTIONAL AND PSYCHOLOGICAL ADJUSTMENTS

Emotional fluctuations are common for mothers in the postpartum period. For some women, emotional fluctuations decrease within several weeks after the delivery, but other women experience more long-lasting emotional swings (O’Hara & Engeldinger, 2018; Pawluski, Lonstein, & Fleming, 2017).

As shown in Figure 11, about 70 percent of new mothers in the United States have what are called the postpartum blues. About two to three days after birth, they begin to feel depressed, anxious, and upset. These feelings may come and go for several months after the birth, often peaking about three to five days after birth. Even without treatment, these feelings usually go away after one or two weeks.

FIGURE 11 Postpartum Blues and Postpartum Depression Among U.S. Women. Some health professionals refer to the postpartum period as the “fourth trimester.” Though the time span of the postpartum period does not necessarily cover three months, the term “fourth trimester” suggests the continuity and the importance of the first several months after birth for the mother and baby.

However, some women develop postpartum depression , which involves a major depressive episode that typically occurs about four weeks after delivery. Women with postpartum depression have such strong feelings of sadness, anxiety, or despair that for at least a two-week period they have trouble coping with their daily tasks. Without treatment, postpartum depression may become worse and last for many months (Di Florio & others, 2014). And many women with postpartum depression don’t seek help. For example, one study found that 15 percent of the women surveyed had postpartum depression symptoms but less than half had sought help (McGarry & others, 2009). Estimates indicate that 10 to 14 percent of new mothers experience postpartum depression.

A research review concluded that the following are risk factors for developing postpartum depression: a history of depression, depression and anxiety during pregnancy, neuroticism, low self-esteem, postpartum blues, poor marital relationship, and a low level of social support (O’Hara & McCabe, 2013). And another recent study revealed that women who had a history of depression were 20 times more likely to develop postpartum depression than women who had no history of depression (Silverman & others, 2017).

Several antidepressant drugs are effective in treating postpartum depression and appear to be safe for breast-feeding women (Howard, Mehta, & Powrie, 2017; Latendresse, Elmore, & Deneris, 2017). Psychotherapy, especially cognitive therapy, is effective in easing postpartum depression for many women (Dennis, 2017; O’Hara & Engeldinger, 2018). Also, engaging in regular exercise may help in treating postpartum depression (Gobinath & others, 2018; McCurdy & others, 2017). For example, a recent meta-analysis concluded that physical exercise during the postpartum period is a safe strategy to reduce postpartum depressive symptoms (Poyatos-Leon & others, 2017).

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connecting with careers

Diane Sanford, Clinical Psychologist and Postpartum Expert

Diane Sanford has a doctorate in clinical psychology, and for many years she had a private practice that focused on marital and family relationships. But after she began collaborating with a psychiatrist whose clients included women with postpartum depression, Dr. Sanford, along with a women’s health nurse, founded Women’s Healthcare Partnership in St. Louis, Missouri, which specialized in women’s adjustment during the postpartum period. Sanford (with Ann Dunnewold) authored Life Will Never Be the Same: The Real Mom’s Postpartum Survival Guide. She also is a medical expert for BabyCenter.com.

Diane Sanford is a leading expert on postpartum depression.Courtesy of Dr. Diane Sanford

For more information about what clinical psychologists do, see the Careers in Life-Span Development appendix.

A mother’s postpartum depression can affect the way she interacts with her infant (Kleinman & Reizer, 2018). A research review concluded that the interaction difficulties of depressed mothers and their infants occur across cultures and socioeconomic status groups, and encompass less sensitivity of the mothers and less responsiveness on the part of their infants (Field, 2010a). Several caregiving activities also are compromised, including feeding (especially breast feeding), sleep routines, and safety practices. In a recent study, postpartum depression was associated with an increase in 4-month-old infants’ unintentional injuries (Yamaoka, Fujiwara, & Tamiya, 2016). Further, a recent study revealed that mothers’ postpartum depression, but not generalized anxiety, were linked to their children’s emotional negativity and behavior problems at 2 years of age (Prenoveau & others, 2017). To read about one individual who specializes in women’s adjustment during the postpartum period, see Connecting with Careers.

Fathers also undergo considerable adjustment in the postpartum period, even when they work away from home all day (Shorey & others, 2017; Takehara & others, 2017). When the mother develops postpartum depression, many fathers also experience feelings of depression (Cameron & others, 2017; Sundstrom Poromaa & others, 2017). Many fathers feel that the baby comes first and gets all of the mother’s attention; some feel that they have been replaced by the baby. A recent study found that 5 percent of fathers had depressive symptoms in the first two weeks following delivery (Anding & others, 2016).

The postpartum period is a time of considerable adjustment and adaptation for both the mother and the father. Fathers can provide an important support system for mothers, especially in helping mothers care for young infants. What kinds of tasks might the father of a newborn do to support the mother? ©Howard Grey/Getty Images

The father’s support and caring can play a role in whether the mother develops postpartum depression (Kumar, Oliffe, & Kelly, 2018). One study revealed that higher support by fathers was related to a lower incidence of postpartum depression in women (Smith & Howard, 2008). Also, a recent study found that depressive symptoms in both the mother and father were associated with impaired bonding with their infant during the postpartum period (Kerstis & others, 2016).

BONDING

A special component of the parent-infant relationship is bonding, the formation of a connection, especially a physical bond between parents and the newborn in the period shortly after birth. Sometimes hospitals seem determined to deter bonding. Drugs given to the mother to make her delivery less painful can makePage 100 the mother drowsy, interfering with her ability to respond to and stimulate the newborn. Mothers and newborns are often separated shortly after delivery, and preterm infants are isolated from their mothers even more than full-term infants.

developmental connection

Attachment

Konrad Lorenz demonstrated the importance of early bonding in greylag geese, but the first few days of life are unlikely to be a critical period for bonding in human infants. Connect to “Introduction.”

Do these practices do any harm? Some physicians believe that during the period shortly after birth, the parents and newborn need to form an emotional attachment as a foundation for optimal development in years to come (Kennell, 2006; Kennell & McGrath, 1999). Is there evidence that close contact between mothers and babies in the first several days after birth is critical for optimal development later in life? Although some research supports this bonding hypothesis (Klaus & Kennell, 1976), a body of research challenges the significance of the first few days of life as a critical period (Bakeman & Brown, 1980; Rode & others, 1981). Indeed, the extreme form of the bonding hypothesis—that the newborn must have close contact with the mother in the first few days of life to develop optimally—simply is not true.

Nonetheless, the weakness of the bonding hypothesis should not be used as an excuse to keep motivated mothers from interacting with their newborns. Such contact brings pleasure to many mothers. In some mother-infant pairs—including preterm infants, adolescent mothers, and mothers from disadvantaged circumstances—early close contact may establish a climate for improved interaction after the mother and infant leave the hospital.

Many hospitals now offer a rooming-in arrangement, in which the baby remains in the mother’s room most of the time during its hospital stay. However, if parents choose not to use this rooming-in arrangement, the weight of the research suggests that this decision will not harm the infant emotionally (Lamb, 1994).

Review Connect Reflect

LG3 Explain the changes that take place in the postpartum period.

Review

· What does the postpartum period involve? What physical adjustments does the woman’s body make during this period?

· What emotional and psychological adjustments characterize the postpartum period?

· Is bonding critical for optimal development?

Connect

· Compare and contrast what you learned about kangaroo care and breast feeding of preterm infants with what you learned about bonding and breast feeding when the mother is suffering from postpartum depression.

Reflect Your Own Personal Journey of Life

· If you are a female, what can you do to adjust effectively in the postpartum period? If you are a male, what can you do to help your partner during the postpartum period?

topical connections looking forward

This chapter marks the beginning of our chronological look at the journey of life. In the next three chapters, we will follow the physical, cognitive, and socioemotional development of infants, including the theories, research, and milestones associated with the first 18 to 24 months of life. You will learn about the remarkable and complex physical development of infants’ motor skills, such as learning to walk; trace the early development of infants’ cognitive skills, such as the ability to form concepts; and explore infants’ surprisingly sophisticated socioemotional capabilities, as reflected in the development of their motivation to share and to perceive others’ actions as intentionally motivated.

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reach your learning goals

Prenatal Development and Birth

1 Prenatal Development

LG1 Describe prenatal development.

The Course of Prenatal Development

Teratology and Hazards to Prenatal Development

Prenatal Care

Normal Prenatal Development

· Prenatal development is divided into three periods: germinal (conception until 10 to 14 days later), which ends when the zygote (a fertilized egg) attaches to the uterine wall; embryonic (two to eight weeks after conception), during which the embryo differentiates into three layers, life-support systems develop, and organ systems form (organogenesis); and fetal (from two months after conception until about nine months, or when the infant is born), a time when organ systems have matured to the point at which life can be sustained outside the womb.

· The growth of the brain during prenatal development is nothing short of remarkable. By the time babies are born, they have approximately 100 billion neurons, or nerve cells. Neurogenesis is the term for the formation of new neurons. The nervous system begins with the formation of a neural tube at 18 to 24 days after conception. Proliferation and migration are two processes that characterize brain development in the prenatal period. The basic architecture of the brain is formed in the first two trimesters of prenatal development.

· Teratology is the field of study that investigates the causes of congenital (birth) defects. Any agent that causes birth defects is called a teratogen. The dose, genetic susceptibility, and time of exposure influence the severity of the damage to an unborn child and the type of defect that occurs.

· Prescription drugs that can be harmful include antibiotics. Nonprescription drugs that can be harmful include diet pills, aspirin, and caffeine. Legal psychoactive drugs that are potentially harmful to prenatal development include alcohol and nicotine.

· Fetal alcohol spectrum disorders are a cluster of abnormalities that appear in offspring of mothers who drink heavily during pregnancy. Even when pregnant women drink moderately (one to two drinks a few days a week), negative effects on their offspring have been found.

· Cigarette smoking by pregnant women has serious adverse effects on prenatal and child development, including low birth weight. Illegal psychoactive drugs that are potentially harmful to offspring include marijuana, cocaine, and heroin. Incompatibility of the mother’s and the father’s blood types can also be harmful to the fetus.

· Environmental hazards include radiation, environmental pollutants, and toxic wastes. Syphilis, rubella (German measles), genital herpes, and AIDS are infectious diseases that can harm the fetus.

· Other parental factors that affect prenatal development include maternal diet and nutrition, age, emotional states and stress, and paternal factors. A developing fetus depends entirely on its mother for nutrition. Maternal age can negatively affect the offspring’s development if the mother is an adolescent or over 35. High stress in the mother is linked with less than optimal prenatal and birth outcomes. Paternal factors that can adversely affect prenatal development include exposure to lead, radiation, certain pesticides, and petrochemicals, as well as smoking.

· Prenatal care varies extensively but usually involves health maintenance services with a defined schedule of visits.

· It is important to remember that, although things can go wrong during pregnancy, most of the time pregnancy and prenatal development go well.

2 Birth

LG2 Describe the birth process.

The Birth Process

Assessing the Newborn

Preterm and Low Birth Weight Infants

· Childbirth occurs in three stages. The first stage, which lasts about 6 to 12 hours for a woman having her first child, is the longest stage. The cervix dilates to about 10 centimeters (4 inches) by the end of the first stage. The second stage begins when the baby’s head starts to move through the cervix and ends with the baby’s complete emergence. The third stagePage 102 involves the delivery of the placenta after birth. Childbirth strategies involve the childbirth setting and attendants.

· In many countries, a doula attends a childbearing woman. Methods of delivery include medicated, natural or prepared, and cesarean.

· For many years, the Apgar Scale has been used to assess the newborn’s health. The Brazelton Neonatal Behavioral Assessment Scale examines the newborn’s neurological development, reflexes, and reactions to people. Recently, the Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS) was created to assess at-risk infants.

· Low birth weight infants weigh less than 5 pounds 8 ounces, and they may be preterm (born before the completion of 37 weeks of gestation) or small for date (also called small for gestational age, which refers to infants whose birth weight is below normal when the length of pregnancy is considered). Small for date infants may be preterm or full term. Although most low birth weight and preterm infants are normal and healthy, as a group they have more health problems and developmental delays than normal birth weight infants. Kangaroo care and massage therapy have been shown to have benefits for preterm infants.

3 The Postpartum Period

LG3 Explain the changes that take place in the postpartum period.

Physical Adjustments

Emotional and Psychological Adjustments

Bonding

· The postpartum period is the name given to the period after childbirth or delivery. The period lasts for about six weeks or until the woman’s body has completed its adjustment. Physical adjustments in the postpartum period include fatigue and hormonal changes.

· Emotional fluctuations on the part of the mother are common in this period, and they can vary a great deal from one mother to the next. Postpartum depression characterizes women who have such strong feelings of sadness, anxiety, or despair that they have trouble coping with daily tasks in the postpartum period. Postpartum depression occurs in about 10 percent of new mothers. The father also goes through a postpartum adjustment.

· Bonding is the formation of a close connection, especially a physical bond between parents and the newborn shortly after birth. Early bonding has not been found to be critical in the development of a competent infant.

key terms

afterbirth

amnion

Apgar Scale

blastocyst

bonding

Brazelton Neonatal Behavioral Assessment Scale (NBAS)

breech position

cesarean delivery

doula

embryonic period

fetal alcohol spectrum disorders (FASD)

fetal period

germinal period

kangaroo care

low birth weight infants

natural childbirth

Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS)

neurons

organogenesis

placenta

postpartum depression

postpartum period

prepared childbirth

preterm infants

small for date infants

teratogen

trophoblast

umbilical cord

key people

T. Berry Brazelton

Tiffany Field

Ferdinand Lamaze