Overview
- Researchers pooled 40 observational studies from 2009–2024 covering 1.6 million pregnancies across five WHO world regions, with 36 studies judged high quality.
- Only 32% of women gained weight within recommendations, while 23% gained below and 45% gained above the advised ranges.
- Excess gestational weight gain correlated with higher birth weight, hypertensive disorders, cesarean delivery, large-for-gestational-age infants, and increased NICU admissions, with lower risks of preterm birth and small-for-gestational-age infants.
- Insufficient gain was linked to preterm birth, low birth weight, small-for-gestational-age infants, and neonatal respiratory distress, with lower risks of cesarean delivery and high birth weight.
- Authors and a linked editorial urge WHO to develop international reference standards and encourage personalized, non-punitive counseling, noting limits such as heterogeneous BMI/GWG categories, under-representation of low-income countries, and possible unmeasured confounders.