Maternal data collection
Participants were followed up at the recruitment visit in the first trimester of pregnancy (9-13 weeks) and at 18-23 weeks gestation in the second trimester of pregnancy. Questionnaires were administered to collect information on demographics, socio-economic status, lifestyle, obstetric and medical history. Pre-pregnancy weight was self-reported while height at early pregnancy was measured in the prenatal care clinic at KKH using the Avamech B1000-M. Pre-pregnancy body mass index (BMI; kg/m2) was calculated as pre-pregnancy weight (kg) divided by height2 (m2).