Association of gestational weight gain with pregnancy complications and delivery outcomes in twins: a study in Northern China

This study developed a gestational age-specific GWG reference for twins in northern China and revealed that underweight and normal weight women experienced greater weight gain during pregnancy than overweight and obese women. Improper GWG is associated with a higher risk of adverse maternal and neonatal outcomes across different pregnancy trimesters. The Chinese BMI classification is more suitable for studying the effect of GWG and providing advice for clinical diet control in China.