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GULF MEDICAL JOURNAL GMJ, ASM 2015;4(S2):S24-S35
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Determinants of Spontaneous Abortion: A Hospital Based
Case-Control Study in Ajman, UAE Lena M. Adel1*, Shahd Farajallah1, Zain Al-Shanableh1, Farah Issa1, Dania Al-Ani1, Jayakumary
Muttappallymyalil2, Mawahib Al Biate3
13rd year MBBS students, 2Department of Community Medicine, Gulf Medical University, Ajman, UAE 3Department of Obstetrics and Gynecology, GMC hospital and Research Centre, Ajman UAE *Presenting Author
ABSTRACT
Objective: The association between various factors and the occurrence of spontaneous abortion among women in the reproductive age group attending GMCH, Ajman, UAE was
determined in this study.
Materials and Methods: It was a case-control study conducted among women admitted to
the OBG department of GMCH, Ajman, UAE. The cases were 60 women hospitalized for
spontaneous abortion and controls were 180 women who had normal delivery. The subjects were interviewed after obtaining consent from them. Their age, parity, gestational age,
nationality, occupation, level of education, history of previous abortion, previous gestational
diabetes, congenital anomalies, hypertension during or after pregnancy, history of
spontaneous abortion and the factors associated with spontaneous abortion were collected.
Data were analyzed using SPSS-21. Chi-square was used to test the association between
various factors and spontaneous abortion. Logistic regression was used to assess the degree of association. Statistical significance was set at p≤0.05.
Results: A total of 60 cases and 180 controls participated in the study. Most of the women
among cases (61.7%) and controls (52.2%) were between 21 and 30 years of age. Majority of
the cases (53.3%) were from Eastern Mediterranean region as compared to controls (49.4%).
No significant association was observed between socio-demographic characteristics and spontaneous abortion. A significant association was observed between regular exercise
especially walking at moderate pace and spontaneous abortion. Type of diet, sleep pattern,
and tobacco use had no significant association with spontaneous abortion. Walking at
moderate pace was a protective factor against spontaneous abortion (AOR =0.22) with
confidence interval of 0.11-0.41. Women who walk regularly during pregnancy are 78% less
likely to have a spontaneous abortion than those who do not. Soft drinks consumption had a protective effect (AOR=0.32) with 95% confidence interval of 0.12-0.87. Women who
consume soft drinks during pregnancy are 68% less likely to have spontaneous abortion than
those who don’t.
Conclusion: This study concluded that there was no association between spontaneous
abortion and any of the socio-demographic characteristics, reproductive health history, sleep pattern, and dietary habits. Walking at moderate space and consuming soft drinks showed
an association with spontaneous abortion and was found to be protective. From the
observations made, the authors recommend to conduct a nationwide research for more
generalizable results.
Keywords: Spontaneous abortion, maternal age, pregnancy, birth control
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INTRODUCTION
Spontaneous abortion has been identified as an important complication associated with
pregnancy at an early age. It is referred as the expulsion of fetus before it has reached a
viable gestational age1. According to the WHO, expulsion of embryo or fetus having
weight 500g or less and which is similar to 20 to 22 weeks of gestational age is termed
as spontaneous abortion. It was reported that most of the causes of spontaneous
abortions were related to maternal factors2,3. Of the total pregnancies 15-20% will have
an adverse pregnancy outcome, spontaneous abortion3.
Among few reasons reported for spontaneous abortion reported, chromosomal
abnormalities led to miscarriage in the first 13 weeks4, followed by endocrine
abnormalities5 and uterine malformations6. A study conducted by Lubna et al. reported
that older age at menarche, consanguineous marriage, husbands older than 50 years
and family history of abortion was significantly associated with spontaneous abortion
whereas age of the mother, socio-economic status, parity, use of spacing methods, and
diabetes or obesity were not associated with spontaneous abortion7. Brenda et al.
reported that certain physical activities, duration of physical activity and frequency of
physical activity were the factors associated with spontaneous abortion8. Direct or
indirect exposure of pregnant mothers to environmental and occupational chemicals
have a negative effect on the pregnancy outcome9.
An overall ratio of 15-20 spontaneous abortions per 100 pregnancies was reported
according to the WHO report. Based on the same report, the fetal death ratio was 227.2
per 1000 recognizable pregnancies. It was reported that around 50% of fetal deaths
occurred before 9 week of gestational period, followed by thirteenth week10.
Many factors contribute to the occurrence of the abortion. The association between the
chance of spontaneous abortion and factors such as the maternal age, order of
pregnancy, and no. of pregnancies, has long been noticed6-9. Other factors such as
substance use like irrational medications, excess of caffeine consumption, tobacco use,
and alcohol consumption have been suggested as possible factors attributable to the
occurrence of spontaneous abortion. However, their effects are believed to be restricted
largely to late stage pregnancies12. Besides, researches have reported that socioeconomic
level, environmental factors, psychosocial factors, and place of residence can play a vital
role in the occurrence of spontaneous abortion11-13.
Studies show that the proportion of clinically apparent miscarriages increases
with parity as well as with maternal and paternal age. The frequency doubles from 12
percent in women before age 20 years to 26 percent in those older than 40 years. For the
same comparison with paternal ages, the frequency of miscarriage increases from 12 to
20 percent 14,10). It is imperative to assess the magnitude of spontaneous abortion for a
number of reasons, most importantly to understand the association between the risk
factors and the occurrence of spontaneous abortion. This will help further efforts to
reduce the rates of possible preventable miscarriages and prevent social, physical and
psychological issues associated with spontaneous abortion. Hence, this research was
conducted to determine the role of age at pregnancy in the occurrence of spontaneous
abortion among women attending a hospital in Ajman, UAE and factors associated with
it.
MATERIALS AND METHODS
A hospital based case-control study was conducted to determine the risk factors
associated with spontaneous abortion among women who were within the reproductive
age (18 years - 45 years) attending the Dept. of Obstetrics and Gynecology in GMC
Hospital, Ajman, UAE. Women who were admitted to the hospital due to spontaneous
abortion of the recent singleton pregnancy were cases and women who were admitted to
the hospital for delivery of the most recent singleton pregnancy were controls. Those who
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were not willing to participate by giving signed informed consent were excluded. The
sample size was calculated considering the exposure rate (age at pregnancy) among the
pregnant women, the Odds Ratio as 3.19 taken from previous study15. The power of the
study was taken as 90% and a significance level of 95% was considered. Thus the
minimum number of cases required was 60. A case control ratio of 1:3 was considered.
Two hundred and forty subjects participated in this research, 60 cases (women who had
spontaneous abortion) and 180 controls (women who delivered normally).
The subjects were interviewed and the questionnaire was filled by the interviewer.
Their age, parity, gestational age, nationality, occupation, level of education, history of
previous abortion, previous gestational diabetes, congenital anomalies, hypertension
during or after pregnancy, history of spontaneous abortion and the factors associated
with spontaneous abortion were collected.
Data cleaning, coding, entry, and analysis were done after data collection. Data
was analysed using the statistical package for social sciences (SPSS) version 21. Chi-
square test was used to find the association between socio-demographic characteristics
and spontaneous abortion. The Odds Ratio was calculated using simple and multiple
logistic regression method. p value 0.05 (two tailed) was considered for statistical
significance level.
RESULTS
This research was conducted among 60 cases and 180 controls.
Table 1: Association between Spontaneous Abortion and Socio-demographic characteristics (N=240)
Table 1 demonstrates the association between spontaneous abortion and socio-
demographic factors. It was observed that majority 37(61.7%) of the women with
spontaneous abortion were aged between 21 and 30 years whereas among the controls
94(52.2%) were in the same age group. It was reported that 32 (53.3%) women with
spontaneous abortion were from the Eastern Mediterranean region in comparison to the
control 89 (49.4%). Related to education, 2 (3.3%) of women who had spontaneous
abortion were illiterate in comparison with controls where it was 1 (0.6%). The proportion
of cases and controls were almost same in other groups of education. With regard to
occupation, spontaneous abortion was reported less among women who had pink collar
jobs 5(8.3%) compared to the control group 30 (16.7%). Regard to BMI, 34 (56.7%) with
Socio-demographic
Characteristics Groups
Cases Controls P value
No. % No. %
Age in years
<=20 years 2 3.3 5 2.8 0.398
21-30 years 37 61.7 94 52.2
> 30 Years 21 35.0 81 45.0
Nationality
South East Asia region 23 38.3 69 38.3
0.700
Eastern Mediterranean region 32 53.3 89 49.4
African region 1 1.7 9 5
Western Pacific region 3 5 12 6.7
Others 1 1.7 1 0.6
Education
Illiterate 2 3.3 1 0.6
0.226
Primary school 1 1.7 14 7.8
High school 14 23.3 37 20.6
Graduate 40 66.7 120 66.7
Post Graduate 3 5.0 8 4.4
Occupation
No collar 46 76.7 124 68.9
0.451 Pink collar 5 8.3 30 16.7
White collar 8 13.3 24 13.3
Grey collar 1 1.70 2 1.1
BMI
< 18.5 2 3.3 4 2.2
0.900 18.5-24.9 24 40 71 39.4
≥25.0 34 56.7 105 58.3
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history of spontaneous abortion were found to be overweight and obese group and among
controls it was 105(58.3%). No statistically significant association was observed between
any of the socio-demographic characteristics and spontaneous abortion.
Table 2: Association between Spontaneous Abortion and Life style factors (N=240)
Table 2 shows the association between spontaneous abortion and life style
factors. It was observed that, 8.3% and 3.3% of women who had spontaneous abortion
were tobacco users and alcohol users; it was 3.9% and 1.1% in controls. It was observed
that 29(48.3%) cases felt stressed during their pregnancies whereas among the controls
it was 105(58.3%).Of the total cases, 29 (48.3%) reported exercising regularly during
their pregnancies while it was 123 (68.3%) among controls. Consumption of caffeinated
drinks was observed in 43(71.7%) of cases and among 150(83.3%) controls. It was
reported by 50(83.3%) cases that they followed a healthy diet regimen compared to the
controls 142(78.9%). No statistically significant association was observed between
participants’ life style factors and spontaneous abortion except for regular exercise
(p≤0.05).
It was observed that, 14 (23.3%) cases and 68(37.8%) of the control group had
access to birth control methods. It was noticed that 8(13.3%) among cases were on birth
control measure before conception, while it was 32(17.8%) among controls.66.7% cases
planned most recent pregnancy compared to 56.7% of the controls. During pregnancy,
91% of cases and controls had regular check-ups. Prior to conception, 46(76.7%) among
cases had regular menstrual cycles while it was 152(84.4%) among controls. No
statistically significant association was observed between spontaneous abortion and
reproductive health history.
Table 3: Association between participants’ family history of abortion and their spontaneous abortion (N=240)
Life style factors
Groups
Cases Controls p value
No. % No. %
Tobacco use Yes 5 8.3 7 3.9 0.171
No 55 91.7 173 96.1
Alcohol use
Yes 2 3.3 2 1.1 0.244 No 58 96.7 178 98.9
Self-reported stress Yes 29 48.3 105 58.3
0.189 No 31 51.7 75 41.7
Regular Exercise Yes 29 48.3 123 68.3
0.018 No 31 51.7 57 31.7
Consumption of Caffeinated drinks
Yes 43 71.7 150 83.3 0.130
No 17 28.3 30 16.7
Followed a healthy diet regimen
Yes 50 83.3 142 78.9 0.475
No 10 16.7 38 21.1
Family History of Abortion
Groups
Cases Controls p value
No. % No. %
History of miscarriages in the family
Yes 20 33.3 45 25.0 0.208
No 40 66.7 135 75.0
Repeated abortions experienced by any family member
Yes 15 25.0 27 15.0 0.077
No 45 75.0 135 85.0
Spouse blood related Yes 14 23.3 31 17.2 0.294
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Table 3 demonstrates the association between participants’ family history of
abortion and spontaneous abortion. It was found that 20 (33.3%) cases and 45 (25%)
controls had history of miscarriages in the family. 15(25%) of women among cases and
27 (15%) of women among controls had family history of repeated abortions. 14(23.3%)
among cases reported to be blood related to the husband while it was 31(17.2%) among
the controls. The Chi Square test showed a non-significant association between
spontaneous abortion and their family history.
Table 4: Association between participants’ physical activities and spontaneous abortion (N=240)
Table 4 describes the association between spontaneous abortion and participant's
physical activity. Majority of the controls 141(78.3%) walked at a moderate pace as
compared to cases 26 (43.3%). The Chi Square test showed walking at moderate pace
had a significant association on the occurrence of spontaneous abortion
(p≤0.01).Association between spontaneous abortion and daily sleeping habits showed
that nap, waking-up at night, and use medication to sleep were not statistically
significant.
Table 5: Association between Participants’ Dietary habits and Spontaneous Abortion (N=240)
Variables Group Cases Controls
p value No. % No. %
Salted fish
Frequently 17 28.3 61 33.9
0.580 Occasionally 17 28.3 54 30
Rarely/Never 26 43.3 65 36.1
Fried fish
Frequently 23 38.3 81 45
0.665 Occasionally 19 31.7 51 28.3
Rarely/Never 18 30 48 26.7
Chips
Frequently 22 36.7 55 30.6
0.646 Occasionally 20 33.3 62 34.4
Rarely/Never 18 30 63 35
Nuts
Frequently 20 33.3 75 41.7
0.196 Occasionally 21 35 68 37.8
Rarely/Never 19 31.7 37 20.6
Chocolate
Frequently 21 35 58 32.2
0.903 Occasionally 20 33.3 65 36.1
Rarely/Never 19 31.7 57 31.7
Leafy vegetables
Frequently 54 90 135 75
0.022 Occasionally 6 10 30 16.7
Rarely/Never 0 0 15 8.3
Fruits Frequently 52 86.7 147 81.7 0.528
No 46 76.7 149 82.2
Variables Group Cases Controls
p value
No. % No. %
Walking at moderate pace Yes 26 43.3 141 78.3 0.001
No 34 56.7 39 21.7
Number of days/ week <3 4 15.3 18 12.8 ----
3-5 12 46.1 48 34.0
>5 10 38.4 75 53.2
Doing House hold chores Yes 48 80.0 156 86.7 0.210 No 12 20.0 24 13.3
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Occasionally 5 8.3 25 13.9
Rarely/Never 3 5 8 4.4
Soft drinks
Frequently 6 10 38 21.1
0.033 Occasionally 16 26.7 61 33.9
Rarely/Never 38 63.3 81 45
Ice cream
Frequently 17 28.3 71 39.4
0.266 Occasionally 25 41.7 68 37.8
Rarely/Never 18 30 41 22.8
Fast food
Frequently 14 23.3 40 22.2
0.944 Occasionally 30 50 88 48.9
Rarely/Never 16 26.7 52 28.9
Beef
Frequently 33 55 96 53.3
0.936 Occasionally 15 25 44 24.4
Rarely/Never 12 20 40 22.2
Chicken
Frequently 46 76.7 129 71.7
0.715 Occasionally 10 16.7 34 18.9
Rarely/Never 4 6.7 17 9.4
Eggs
Frequently 42 70 131 72.8
0.378 Occasionally 9 15 33 18.3
Rarely/Never 9 15 16 8.9
Fruit juices
Frequently 40 66.7 132 73.3
0.424 Occasionally 14 23.3 38 21.1
Rarely/Never 6 10 10 5.6
Energy drinks
Frequently 1 1.7 8 4.4
0.253 Occasionally 4 6.7 5 2.8
Rarely/Never 55 91.7 167 92.8
Vegetables
Frequently 59 98.3 165 91.7
0.186 Occasionally 1 1.7 10 5.6
Rarely/Never 0 0 5 2.8
Dietary habits of cases and controls showed that use of leafy vegetables and
consumption of soft drinks were found to be significantly associated with spontaneous
abortion (p≤0.05) whereas use of fried fish, skipping breakfast, use of salted fish, use of
fried chips, chocolate intake, and fast food consumption were not significantly
associated. Details are given in table 5.
Table 6: Distribution of protective factors of Spontaneous abortion
Performing the Binary logistic regression model on the data with significant
variables revealed that consumption of leafy vegetables was not a significant factor
towards spontaneous abortion ([OR=0.501], [CI 95% 0.197-1.269]). Exercise revealed
OR=0.434 [CI 0.239-0.787], a significant association with spontaneous abortion and
Variables
Group
Crude
OR
Confidence Interval
Adjusted OR
Confidence Interval
Exercise No 1 -- -- -- Yes 0.434 0.239-0.787
-- --
Walking at moderate pace
No 1 -- 1 -- Yes 0.212 0.114-0.394 0.215 0.113-0.412
Leafy vegetables Frequently 1 -- -- -- Occasionally 0.500 0.197-1.270 -- --
Rarely/Never 0.0 -- -- --
Soft drinks Rarely/Never 1 -- 1 - Occasionally 0.559 0.286-1.10 0.584 0.271-1.214 Frequently 0.334 0.131-0.864 0.321 0.119-0.867
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walking at moderate pace had a possible protective effect OR=0.212 [CI 0.114-
0.394].Pregnant women who walk regularly at moderate pace are 80% less likely to have
a spontaneous abortion than those who do not. Consumption of soft drinks showed as
a possible protective factor OR=0.334 [CI 0.131-0.864]. During pregnancy, women who
consume soft drinks are 68% less likely to have spontaneous abortion than those who
do not.
DISCUSSION
Spontaneous abortion, a clinically recognized pregnancy loss before the 20th week of
gestation, is the most common complication of pregnancy. A recent historical cohort
study from Soroka Medical Center of Israel reported fetal loss due to spontaneous
abortion in 9.9% of women16. The present hospital based case-control study included 60
cases with spontaneous abortion and 180 controls.
According to a population based register linkage study which was conducted in
Denmark on 634272 women, advanced maternal age showed a very strong association
with the miscarriage in healthy women. The same study concluded that there’s an
increasing risk of fetal loss with increasing maternal age in women aged more than 30
years. It was observed that at 42 years of age, more than half of all pregnancies resulted
in adverse outcomes including spontaneous abortion and multiple other outcomes. This
increasing risk of spontaneous abortion was observed in both nulliparous and parous
women, regardless of parity, number of previous spontaneous abortions, or calendar
period17. Studies which were conducted in southeast Spain and Italy showed a
correlation between advanced maternal age and the probability of fetal loss (r = 0.067; p
= 0.000)18,19. The results of the previous two studies were not in concordance with ours,
as we found no significant association between age and spontaneous abortion (P=0.398).
The difference could be explained by the fact that our study sample didn't include many
women in advanced age groups. Furthermore, we found that there's no significant
association between the age at first pregnancy and spontaneous abortion (P=0.451). As
for the mean age of our study sample, it was almost the same for both groups.
It is well known that risk of miscarriage increases with age. A retrospective
population-based study among women aged 25–44 years in four European countries viz.
Denmark, Germany, Italy and Spain also reported a higher risk of miscarriage in women
aged ≥35 years, after adjusting for various factors like reproductive history and
country20. Majority of cases were from Eastern Mediterranean region where women get
married early and conceive at an early age and so most of the cases were in that age
group.
Similar results of a case-control study conducted on the population of the United
Kingdom showed that there was no evidence of an effect of social class, when measured
by either the husband/partner’s (P = 0.10) or the woman’s own (P = 0.29) occupation.
However, the same study suggested that unemployment might be associated with (non-
statistically significant) increased odds of miscarriage (adjusted odds ratio when both
parents were unemployed was 1.46 [95% CI 0.87–2.42]) and there was weak evidence of
an increasing trend in odds with increasing educational attainment (P = 0.04)21. No
statistically significant relation was seen between spontaneous abortion and
participants’ occupation and education. Our study noted an increased risk of
spontaneous abortion among unemployed (No collar) group (76.7%) compared to the
employed women. Because our sample of cases and controls included more unemployed
women than employed.
A study done in Denmark to investigate the relationship between different
indicators of socioeconomic position and the risk of spontaneous abortion reported that
women with <10 years of education had an elevated risk of spontaneous abortion when
compared to women with >12 years of education (HR 1.19: 95% CI 1.05 to 1.34)22. But
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our study result contradicts their findings as a rate of increase of spontaneous abortion
is showed according to the increase in the level of education.
In a study in Denmark, women with less than 10 years of education were found
to have an elevated risk of spontaneous abortion when compared to women with >12
years of education (HR 1.19: 95% CI 1.05 to 1.34)22. Education is not significantly related
to spontaneous abortion in the present study.
Our study noted that majority of the participants who experienced spontaneous
abortion was from Eastern Mediterranean region (53.3%) and South East Asia region
(38.3%). A study reported that higher abortion rates are associated with higher
education, higher income, urban residence, Han nationality (East Asian ethnic people),
and pregnancies after first birth. Place of residence, was found to have significant impact
on incidence of abortions after controlling for age and number of conceptions23.
In a previous study, it was observed that the effect of BMI on the risk of
spontaneous abortion was significant compared with the reference group (BMI 18.5 to
24.9 kg/m2). Underweight women also had the same risk of spontaneous abortion while
there was progressive increase of risk in overweight and obese groups (p <0.05)24whereas
in our study increased risk of spontaneous abortion was observed in underweight group
compared to controls but association between BMI and spontaneous abortion was not
significant (p>0.05). This may be because our sample size consisted mostly of women
who were physically fit and fell with normal range of BMI (18.5 to 24.9kg/m2).
Furthermore, it is also noticed that the proportion of risk is comparatively increasing
from 3.3% to 56.7% with increasing level of BMI; though it is almost same in controls.
A study conducted among women who experienced spontaneous abortion in India
revealed that 4.88% of women who were exposed to tobacco had spontaneous abortion
and 4.99% of women who had spontaneous abortion were not exposed to tobacco out of
a total of 276,897 pregnancies25. Another study conducted in 2014 stated that smoking
is a major risk factor for spontaneous abortion along with many other life style factors26.
A meta-analysis of data from studies on smoking and pregnancy in the USA showed a
positive association between smoking and spontaneous abortion as it was estimated that
19,000- 141,000 cases of spontaneous abortion were attributed to tobacco every year27.
A study revealed that there was an association between tobacco use and spontaneous
abortion and concluded that women who experienced spontaneous abortion smoked
more often during pregnancy in comparison with women among the control who didn’t
smoke during pregnancy28. A nested case-control study using prospective data from a
population-based cohort comprising 11,088 women aged 20-29 years showed an
increased risk of spontaneous abortion among current smokers with an adjusted OR
1.20 (CI: 1.04-1.39) for every extra five cigarettes smoked per day29. However, another
case-control study reported that women who smoked 10-19 cigarettes and 20 or more
cigarettes per day did not have significantly increased ORs for spontaneous abortion,
after adjusting for other risk factors30. Among the tobacco users, our study observed that
41.7% of the participants experienced spontaneous abortion and among the non-users,
it was 24.1%. It was proven that there is an association between tobacco use and
spontaneous abortion while in our study smoking was not found to be a risk factor
(p>0.05). This difference might be due to a small number of smokers in our study sample.
It was reported in a study that consumption of 5 or more units alcohol per week
and 375 mg or more caffeine per day during pregnancy might increase the risk of
spontaneous abortion30.A study done among 430 couples in Denmark reported that
alcohol intake of both male and female during the week of conception increased the risk
of spontaneous abortion31. One review reported the relationship between maternal
alcohol consumption during pregnancy and spontaneous abortions32. Researchers used
data from nearly 93,000 pregnant women and found that women who had two drinks a
week had 1.5 times risk of miscarriage as those who did not drink at all33. It was also
reported that even low amount of alcohol consumption during early pregnancy increased
the risk of spontaneous abortion substantially34. Another study reported that more than
12% of all recognized pregnancies end in a spontaneous abortion and warranted
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abstinence from alcohol in the first 16 weeks of pregnancy35. In our study, alcohol users
are only a small group to statistically analyze the effect of alcohol consumption on
spontaneous abortion. According to a cohort study that included 436 women, there was
a significant association between physical activities and spontaneous abortion. Physical
activity during pregnancy not only decreases the risk of miscarriage (p = 0.068) but also
has a positive relationship with the implantation rates which as a result intensifies the
chance of pregnancy36.These results were in concordance with our study which also
showed a significant positive effect of physical activities on spontaneous abortion
(p<0.018), especially walking at moderate pace (p<0.001).Among the participants who
walk at moderate pace, only 15.5% experienced spontaneous abortion compared to
84.4% controls suggesting positive effect of exercise in preventing spontaneous abortion.
Another study conducted in Denmark37 by the National Institute of Public Health showed
a significant association between exercise early in pregnancy and spontaneous abortion;
there was an increased risk of miscarriage with exercise prior to 18 weeks of pregnancy,
while our study showed no such significance. Probably the type and duration of exercise
could account for the difference in the results; our result supports the same in that, as
the number of days of exercise per week increases, the risk also increases from 15.3%
to 38.4%. A study from South Korea, found that 20% of working women who regularly
handled heavy items during pregnancy experienced spontaneous abortion38.
A case control study conducted in UK reported that women who described their
index pregnancy as ‘planned’ had 40% reduced odds of miscarriage39.While Our study
indicated no greater risk of spontaneous abortion among women who experience an
unplanned pregnancy than among women experiencing a planned pregnancy, which is
consistent with another study that confirmed the lack of evidence for an association
between unplanned pregnancies and adverse pregnancy outcome40.In our study, there
was no clear association between regular checkups and spontaneous abortion. On the
other hand, there was an observed reduced risk of abortion in women with regular
checkups, by increasing early detection of risk factors and providing women with
information to help them avoid risky behaviors during pregnancy41.This difference was
believed to be a result of increased awareness about the importance of professional
supervising pregnancy among the women. In our study population, more than 90%
among women with spontaneous abortion as well as controls had regular checkups
throughout their pregnancies.
A hospital based case control study in Milan, Italy reported that the risk of
spontaneous abortion was inversely and significantly related to green vegetables, fruit,
milk, cheese, eggs and fish consumption. Odds ratio showed a 2 (CI 1.1-3.6) and 1.6 (CI
1.1-2.3) times higher chance of spontaneous abortion among the participants who used
butter and oil respectively. The study also reported that there was no association
between meat, liver, ham and carrots intake and the risk of spontaneous abortion42. Our
study noted less intake of salted fish and frequent intake of leafy or any other vegetables,
fruits/juices, beef, chicken, eggs increased the risk of spontaneous abortion.
A prospective study found 1.3 times higher risk for spontaneous abortion if they
used alcohol more than 300 mg/day, after adjustment for maternal age, pregnancy
history, cigarette and alcohol consumption, employment, race, gestational age at
interview, and marital and socioeconomic status. If they consume three or more cups of
decaffeinated coffee during the first trimester, OR was found to be 2.4 (CI = 1.3-4.7) in
the same model43. Drinking 3 cups of tea or coffee was found to be associated with
elevated risks of spontaneous abortion (Adjusted OR= 2.63, 95% CI = 1.29-5.34) in one
study44 whereas another study found no association between caffeine consumption and
miscarriage45. But a recent study reports strong evidence for association between
caffeine consumption during pregnancy and miscarriage46. Our study also supported
this fact by a proportion of 71.7% in those who had the habit of consuming caffeinated
drinks and had exposure to spontaneous abortion.
A retrospective case-control study indicated the family history of spontaneous
abortion among I, II and III generation relatives of the couples to be two to three times
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higher than that of the general population (55.5, 47.6 and 32.6% for female relatives,
and 45.8, 44.1 and 15.1% for male relatives)47. But our study shows that 66.7% of the
cases do not have family history of spontaneous abortion. Only 25% of the cases had
family history of repeated abortions.
A prospective study conducted on 3,953 pregnant women to find the relation of
work-related psychological stress to spontaneous abortion reported that stressful work
had no association with an increased risk of spontaneous abortion, cigarette smoking (p
= 0.02), and primi gravidity (p = 0.06)48. In our study, self-reported stress was reported
among 48.3% of cases and 58.3% of controls with no statistically significant relationship.
A review article reported that consanguineous marriages were associated with an
increased risk for birth defects and disorders, but no major adverse associations with
reproductive parameters such as miscarriages are documented49. Our study support the
same result as blood related marriage has not shown any significant effect on
spontaneous abortion, but 22.3% who were blood related experienced miscarriage.
Limitations of this research include many women who just had an abortion
refused to participate in the study as they were stressed emotionally and physically,
recall bias and whatever information gathered it is self-reported.
CONCLUSION
This study concluded that there was no association for any of the socio-demographic
characteristics, participants’ life style factors, reproductive health history, sleeping habits,
and dietary habits towards the occurrence of spontaneous abortion among women; except
regular exercise of walking at a moderate space, consuming leafy vegetables and soft
drinks. It was found that walking at moderate pace is a protective factor for spontaneous
abortion, and pregnant women who walk regularly during pregnancy are 80% less likely
to have a spontaneous abortion than those who do not. From the observations made, the
authors recommend to conduct a nationwide research for more generalizable results.
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