Optimizing maternal weight gain to improve neonatal Health: A nationwide birth cohort analysis in Taiwan

Gestational weight gain (GWG) is a modifiable factor influencing maternal and neonatal health. Current GWG guidelines, largely derived from Western populations, may not align with the physiological and sociodemographic characteristics of Asian women. This study examined the associations between GWG and pregnancy outcomes across pre-pregnancy body mass index (BMI) categories in a nationally representative Taiwanese cohort.

We analyzed 18,970 full-term singleton mother-infant pairs from the Taiwan Birth Cohort Study. GWG was calculated from self-reported pre-pregnancy and delivery weights. BMI was classified using Taiwan's Ministry of Health and Welfare standards: underweight (<18.5 kg/m²), normal weight (18.5-23.9 kg/m²), overweight (24.0-26.9 kg/m²), and obese (≥27.0 kg/m²). Outcomes included low birthweight (LBW), small for gestational age (SGA), large for gestational age (LGA), high birthweight, gestational diabetes mellitus (GDM), gestational hypertension, and pre-eclampsia. Multivariable logistic regression was stratified by BMI and adjusted for maternal age, parity, education, urbanization, and infant sex.

GWG was positively associated with birthweight in all BMI groups. Inadequate GWG was linked to higher risks of LBW, SGA, and maternal complications, particularly in underweight women. Overweight and obese women showed greater tolerance to higher GWG for GDM and gestational hypertension; however, excessive GWG consistently increased pre-eclampsia risk across BMI groups.

Findings highlight the need for BMI-specific GWG recommendations in Taiwan. Among underweight women, insufficient GWG was associated with higher risks of adverse outcomes, suggesting that current GWG targets for this group may warrant re-evaluation, while current guidelines appear adequate for overweight or obese women.