Objective To investigate the relationship between maternal weight changes during early pregnancy, gestational weight gain (GWG), and infant neurodevelopmental trajectories at 0–3 years. Methods This retrospective cohort study analyzed singleton pregnancies with complete clinical data and Ages and Stages Questionnaires, Third Edition (ASQ-3) records from Beijing Obstetrics and Gynecology Hospital (January 2020–June 2024). Participants were divided into four groups based on maternal weight change in early pregnancy and the presence or absence of catch-up weight gain in mid-to-late pregnancy. “Catch-up weight gain” was defined as total GWG meeting or exceeding Chinese recommendations. Neurodevelopment was assessed using ASQ-3 at 2, 6, 8, 12, 18, 24, and 36 months. Statistical analyses included ANOVA, χ² tests, or Fisher’s exact tests, and multivariable logistic regression was used to assess associations between weight-change patterns and neurodevelopmental trajectories. Results A total of 10,570 pregnant women were analyzed, categorized into four groups: appropriate early-pregnancy weight gain (n=4465), early-pregnancy weight loss without catch-up GWG (n=399), and early-pregnancy weight loss with catch-up GWG (n=1092), excessive early-pregnancy weight gain (n=4614). Two distinct neurodevelopmental trajectories were identified across all ASQ-3 domains. Trajectory 1, characterized by low scores, suggests a risk of developmental delay, whereas Trajectory 2, marked by high scores, indicates normal or optimal development. Infants of mothers with early-pregnancy weight loss and inadequate catch-up GWG exhibited a significantly higher prevalence of Trajectory 1 in the personal-social domain (10.5% [42/399]) compared to those with appropriate early-pregnancy gain (6.4% [284/4,465]) or excessive gain (5.4% [250/4,614]) (P < 0.001). Logistic regression revealed a 73.4% increased risk of personal-social delay (adjusted odds ratio [aOR] = 1.734; 95% confidence interval [CI]: 1.232–2.441; P = 0.002) in this group. No significant associations were observed for other domains (P > 0.05) or in groups with catch-up GWG/excessive early-pregnancy weight gain. Conclusion Early-pregnancy weight loss without subsequent catch-up GWG is associated with an elevated risk of delayed personal-social development in infants. Targeted weight management during mid-to-late pregnancy may mitigate neurodevelopmental risks in this population.

Catch-Up Weight Gain, Weight Loss, Early Pregnancy, Neurodevelopmental Trajectories, ASQ-3