First trimester body mass index and pregnancy outcomes in expectant women at Moi Teaching and Referral Hospital, Eldoret-Kenya

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.