Impact of early-pregnancy weight loss and catch-up weight gain on neurodevelopmental outcomes and trajectories in infants aged 0-3 years: the Beijing Birth Cohort Study.

To examine associations of maternal early-pregnancy weight change, total gestational weight gain (GWG), and mid-to-late pregnancy GWG rate (GWGR) with infant neurodevelopment from 0-3 years. Utilizing data from the prospective Beijing Birth Cohort Study, this study investigated 5,951 singleton mother-infant pairs. Infant neurodevelopment was assessed via Ages and Stages Questionnaires, Third Edition (ASQ-3) at 2, 6, 8, 12, 18, 24, and 36 months. Latent trajectory modeling identified domain-specific ASQ-3 trajectories. Multivariable logistic regression evaluated associations of early-pregnancy weight loss, total GWG, and GWGR with risk of developmental delay based on ASQ-3 screening thresholds and ASQ-3 low-score trajectories. Early-pregnancy weight loss was associated with increased risks of infant developmental delay based on ASQ-3 screening thresholds in problem-solving (aOR=1.565, 95% CI: 1.211-2.021) and personal-social domains (aOR=1.222, 95% CI: 1.049-1.424), along with a higher likelihood of following ASQ-3 low-score trajectories in problem-solving domain(aOR=1.209, 95% CI: 1.008-1.451). Among women with early-pregnancy weight loss, failure to achieve catch-up GWG correlated with less favorable ASQ-3 screening outcomes and low-score trajectories across multiple domains. Conversely, catch-up GWG after weight loss was only linked to personal-social and problem-solving developmental delays respectively. Additionally, excessive GWGR after weight loss also showed less favorable ASQ-3 screening outcomes and trajectories. Among women with early-pregnancy weight loss, failure to achieve catch-up GWG or having excessive GWGR was significantly associated with higher risk of infant developmental delay based on ASQ-3 screening thresholds and adverse ASQ-3 low-score trajectories. However, adverse neurodevelopmental associations remained present despite subsequent GWG within recommended ranges.