10th U6+ Consortium of African Universities International Conference

Maternal body mass index (BMI) in early pregnancy is a modifiable determinant of maternal and fetal health. Sub-Saharan Africa faces a dual nutritional burden of persistent undernutrition alongside rising overweight and obesity. In Kenya, where both extremes coexist, the relationship between early-pregnancy BMI and stillbirth risk remains poorly characterised, limiting evidence-based antenatal care. We examined this relationship using the STRiDE (Stratification of Risk of Diabetes in Early Pregnancy) cohort, Eldoret, Kenya. The objective of the study was to examine the association between early-pregnancy BMI category and stillbirth risk, before and after adjustment for maternal and pregnancy-related factors. This secondary analysis of the STRiDE prospective cohort (a multicentre gestational diabetes study; Eldoret, Kenya, April 2015–May 2019) used multivariable logistic regression to assess stillbirth risk by early-pregnancy BMI category, adjusting for maternal age, parity, gestational age at enrollment, and family history of diabetes, hypertension, or gestational diabetes (clustering by recruitment site was negligible, ICC <0.001). Of 4,101 enrolled women, 2,612 (2,533 live births, 79 stillbirths) had complete data and were included. Stillbirth (fetal death at ≥20 weeks gestation) was the primary outcome; BMI was categorised as underweight (<18.5 kg/m²), normal (18.5–24.9 kg/m², reference), overweight (25.0–29.9 kg/m²), or obese (≥30.0 kg/m²). Most participants had a normal BMI (57.7%); 38.3% were overweight/obese, and 4.0% were underweight. Overall, stillbirth prevalence was 3.0%, highest among underweight (5.8%) and overweight women (4.3%) versus normal BMI (2.2%), and 3.4% among obese women. After adjustment, both underweight (aOR 3.29, 95% CI: 1.29–8.36, p=0.01) and overweight (aOR 2.48, 95% CI: 1.37–4.48, p<0.001) were significantly associated with stillbirth; obesity was not (aOR 1.65, 95% CI: 0.68–4.01, p=0.27). Both underweight and overweight, but not obesity, were independently associated with increased stillbirth risk, consistent with a J-shaped relationship between early-pregnancy BMI and stillbirth. Early BMI assessment may help identify women at elevated stillbirth risk in similar LMIC settings.