Psychology
Maria Castro 
siegler5e_ch022019.pptxPrenatal Development and the Newborn Period
Presentation Slides
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Chapter
Prenatal Development
Hazards to Prenatal Development
The Birth Experience
The Newborn Infant
Outline of Chapter
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Epigenesis: The emergence of new structures and functions in the course of development
Prenatal Development
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Gametes (germ cells): Reproductive cells—egg and sperm—that contain only half the genetic material of all other cells in the body
Meiosis: Cell division that produces gametes
In meiosis, 23 chromosomes from mother and 23 chromosomes from father lead to conception—> 23 pairs of chromosomes.
Conception: The union of an egg from the mother and a sperm from the father; also called fertilization
Zygote: a name for the fertilized egg cell
Conception
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Female Reproductive System
Conception (cont.d)
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Sperm nearing the egg
Conception (cont.d)
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Four developmental processes that transform a zygote to an embryo to a fetus
Mitosis: Cell division resulting in two identical daughter cells
Cell migration: Newly formed cells move away from point of origin
Cell differentiation: Cells start to specialize in structure and function
Apoptosis: Genetically programmed death of cells not required/necessary
Developmental Processes
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| Time | Period | Description |
| Conception to 2 weeks | Germinal | Begins with conception and lasts until the zygote becomes implanted in the uterine wall. Rapid cell division takes place. |
| 3rd to 8th week | Embryonic | Following implantation, major development occurs in all the organs and systems of the body. Development takes place through the processes of cell division, cell migration, cell differentiation, and cell death, as well as hormonal influences. |
| 9th week to birth | Fetal | Continued development of physical structures and rapid growth of the body. Increasing levels of behavior, sensory experience, and learning. |
Developmental Processes (cont.d)
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Identical Twins
Twins that result from the splitting in half of the zygote
Each of the two resulting zygotes have exactly the same set of genes
Fraternal Twins
Twins that result when two eggs happen to release in fallopian tubes at the same time
Fertilized by two different sperm
Fraternal twins have only half their genes in common; are no more similar than any other biological siblings
Early Development
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Neural tube: A groove formed in the top layer of differentiated cells in the embryo that eventually becomes the brain and spinal cord
Amniotic sac: A transparent, fluid-filled membrane that surrounds and protects the fetus
Placenta: A support organ for the fetus that permits the exchange of materials carried in the bloodstreams of the fetus and mother
Umbilical cord: A tube containing the blood vessels connecting the fetus and placenta
Early Development (cont.d)
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Movement
Movement starts 5–6 weeks after conception
Emergence of hiccups, swallowing
Movement of limbs, fingers
Respiratory readiness for breathing independently after birth
Behavioral Cycles
Rest–activity cycles; less activity in latter half of prenatal period
Circadian rhythm apparent
REM during active sleep
Fetal Behavior
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Hearing—responds to various sounds from at least 6 months
Smell—amniotic fluid takes on odor from what the mother eats
Taste—can detect flavors in the amniotic fluid
Touch—contact with parts of the body; grasping umbilical cord, rubbing face, sucking thumb
Sight—minimal
Fetal Experience
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Dishabituation
The introduction of a new stimulus rekindles interest following habituation to a repeated stimulus.
Habituation
A simple form of learning that involves a decrease in response to repeated or continued stimulation
Fetal Learning
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Miscarriage
15% of U.S. clinically recognized pregnancies end in miscarriage.
At least 25% to possibly as high as 50% of women experience at least one miscarriage.
Sensitive Period
When a certain type of development is most likely, although it may still happen later
Critical Period
When a particular type of development growth (in body or behavior) must happen if it is to happen
Hazards to Prenatal Development
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Cigarettes
Slow fetal development, low birth weight, possible links to SIDS
Environmental Pollutants
Potential birth defects
Occupational hazards
Automobile exhaust; factory workers
Alcohol
Fetal alcohol syndrome
Maternal factors
Age, nutrition, disease, emotional state, mental illness
Environmental Hazards to Fetus and Newborn
Hazards to Prenatal Development (cont.d)
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Teratogen: A potentially harmful nongenetic agent
Dose–response radiation: Potential problems depend on how the mother is exposed to the teratogen and for how long. The more exposure, the more at risk the fetus becomes.
Timing of exposure is also important for determining level of risk; exposure in the embryonic period is more dangerous than exposure later in the fetal period.
Teratogens
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| Teratogen | Effects | Timing |
| Radiation | Disrupted development of central nervous system | 8 to 15 weeks most critical |
| Growth and developmental retardation | 3 to 8 weeks most critical | |
| Microcephaly | 3 to 38 weeks | |
| Tobacco use by mother | Limb malformation, urinary tract damage | 4 to 6 weeks |
| Tobacco use by father (secondhand smoke) | Low birth weight, reduction in weight by an average of 2 oz. | Late pregnancy |
| Alcohol | Fetal alcohol syndrome | 3 to 38 weeks |
| Fetal alcohol effect | 3 to 38 weeks | |
| Growth and developmental retardation Craniofacial dysmorphism | 3 to 38 weeks | |
| Cocaine | Growth retardation, small head size | 3 to 8 weeks |
| Premature birth, problems with placenta, low birth weight | After 17 weeks | |
| Attention difficulties, emotional regulation | After birth for several years |
Teratogens (cont.d)
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Age
Infant mortality rate higher for teen mothers 15 years or younger
Women delaying pregnancies to their 30s or 40s risk infertility and having babies with genetic abnormalities, such as Down Syndrome
Nutrition
General malnutrition of mother affects growth of fetal brain; later cognitive impairments
Spina bifida, neural tube defects
Maternal Factors Affecting Prenatal Development
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Disease
Rubella
STIs can damage CNS of fetus
Infections, such as influenza may lead to schizophrenia
Zika virus – microcephaly (small brain)
Maternal Emotional State
High maternal stress leads to increased stress hormone levels
Could lead to behavior problems in children who were prenatally exposed to high levels of stress hormones
Maternal Factors (cont.d)
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Fetal alcohol effects, or FAE—when an infant has some but not all effects of FASD. Roughly 1 in 1000 infants born in the United States has FAE.
Fetal alcohol spectrum disorder, or FASD—when a mother’s alcohol consumption during pregnancy affects the fetus; can include facial deformities, intellectual disabilities, attention problems, hyperactivity, and other defects
Sudden infant death syndrome, or SIDS—when an infant 1 year of age or less dies suddenly and unexpectedly with no cause
Potential Results of Hazards
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Birth of baby occurs after 38 weeks of conception
Uterine muscles contract initiating birth
Baby in normal head-down position
Mother experiences pain
Baby experiences squeezing
Reduces overall size of fetus’s large head
Plates of skull overlap during birth
Stimulates hormone production
Forces amniotic fluid out of lungs (and ears)
The Birth Experience
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The Birth Experience (cont.d)
Head plates: Pressure on the head during birth can cause the separate plates of the skull to overlap, resulting in a temporarily misshapen head. Fortunately, the condition rapidly corrects itself after birth.
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Childbirth practices vary across cultures.
All cultures pursue dual goals:
Survival and health of mother and baby
Social integration of baby
Cesarean (C-section): Surgical delivery of baby when birth complications arise
Doula: Individuals trained to assist women in terms of emotional and physical comfort during labor and delivery
Diversity of Childbirth Practices
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A healthy baby interacts with environment right away
Explores and learns about new environment
Exploration influenced by baby’s state of arousal
The Newborn Infant
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State: Level of arousal and engagement
ranges from deep sleep to intense activity.
Infant States of Arousal
Newborn States: This figure shows the average proportion of time, in a 24-hour day, that Western newborns spend in each of the six states of arousal. There are substantial individual and cultural differences in how much time babies spend in the different states.
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Sleep
Newborns sleep twice as much as adults (16-18 hours/day).
Total sleep time declines regularly throughout childhood and more slowly throughout life.
Rapid eye movement (REM) sleep: Active sleep state, characterized by quick, jerky eye movements under closed eyelids
Associated with dreaming in adults
Non-REM sleep: Quiet or deep sleep state characterized by absence of motor activity or eye movements
More regular, slower brain waves, breathing, and heart rate
Infant States of Arousal (cont.d)
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Infant States of Arousal (cont.d)
Total sleep and proportion of REM and non-REM sleep across the life span
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Crying
Infants cry to get attention of caregivers.
Some reasons for crying include illness, pain, and hunger.
Crying is normal behavior.
Peaks around 6–8 weeks of age, and decreases around 3–4 months of age
Soothing: Consoling crying baby
Swaddling: A soothing technique, used in many cultures; involves wrapping baby tightly in cloths or a blanket
Infant States of Arousal (cont.d)
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Response to Distress
A study found that a caregiver’s quick response to crying results in less crying several months later.
Another study found that ignoring crying during the first 9 weeks reduced crying during the next 9 weeks.
Colic: Excessive, inconsolable crying by a young infant for no apparent reason
Infant States of Arousal (cont.d)
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Infant Mortality
Death during the first year after birth
In the United States, in 2015, there were 5.87 deaths per 1000 births.
Low Birth Weight (LBW)
Average newborn 7 ½ pounds
LBW – less than 5 ½ pounds at term; also known as small for gestational age
Premature (preterm) babies – born before 37 weeks after conception;
LBW babies – high level of medical complications; high rates of neurosensory deficits, frequent illnesses, lower IQ scores
Negative Outcomes at Birth
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Carry
Caress
Cuddle
Best way to help low birth weight infants—physical contact; social interaction
Overcoming Low Birth Weight
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Multiple Risk Models
Effects of cumulative and multiple risks affects normal functioning in child
Range from attachment problems to language development to well-being
Poverty as a Developmental Hazard
Multiple risks strongly related to lower SES
Resilience: When an infant develops successfully, even with hazards such as low birth weight, poverty, or other teratogens
Negative Outcomes at Birth (cont.d)
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