Abstract:
Background: Aberration of Body Mass Index (BMI) is becoming a significant public
health problem globally. Even though abnormal first trimester BMI has been
identified as a risk factor to safe pregnancy, there are limited local studies in Kenya
on its extent and impact on pregnancy outcomes.
Objective: To determine the association between first trimester BMI and pregnancy
outcomes among women seeking antenatal care in the first trimester and delivery at
Moi Teaching and Referral Hospital.
Methods: This was a prospective cohort study of pregnant women seeking antenatal
care at Moi Teaching and Referral Hospital within their first trimester. Systematic
sampling was used; socio-demographic and clinical data were collected using an
interview schedule and review of chart notes, respectively at recruitment. Participants‟
first-trimester BMI was measured at recruitment. The women were followed up
during subsequent antenatal visits (second and third trimesters), admission to
labor/antenatal wards or at termination of pregnancy to record clinical events or
pregnancy outcomes. Those who failed to show up on subsequent visits, were
followed up through phone calls. Association between first-trimester maternal BMI
and adverse pregnancy outcomes were reported using p-value (critical value ≤0.05)
and odds ratios at 95% confidence interval. Logistic regression was used to adjust for
the effect of intermediate variables.
Results: This study enrolled 256 participants but only 255 completed the study
follow-up, of whom 128 (50.2%) had an abnormal first trimester BMI while127
(49.8%) had a normal first trimester BMI. The women with abnormal first trimester
BMI were categorized according to WHO BMI classification as: underweight,
overweight, and obese at 11.4%, 36.5% and 2.4% respectively. About one fifth
(19.6%; n=50) of all study participants had an adverse maternal outcome with more
than two-thirds of them (68%; n=34) having an abnormal first trimester BMI.
Abnormal first trimester maternal BMI increased the risk of adverse maternal
outcome two-fold (AOR=2.159; 95% CI: 1.258, 3.707). Abnormal maternal first
trimester BMI increased the risk of adverse neonatal outcomes three-fold
(AOR=3.076; 95% CI: 1.575, 6.006).
Conclusion: Caesarian section and miscarriage were the most common maternal
adverse outcomes reported in this study. Intrauterine fetal death was the most
common adverse neonatal outcome observed. There was a statistically significant
association between maternal first-trimester body mass index and adverse neonatal
and maternal outcomes.
Recommendation: There is need for a multidisciplinary approach in the management
of expectant women with abnormal first trimester BMI to achieve favourable neonatal
and maternal outcomes. Future studies using more robust study designs in multiple
sites and matched larger populations of expectant women should be conducted to
validate the findings of this study.