Objective: To analyze the impact of maternal metal exposure during early pregnancy on the physical development of offspring at 1 and 3 years of age, so as to provide scientific evidence for reducing the adverse effects of heavy metals on their health. Methods: From 2024 to 2018, a total of 1 588 mother child pairs from the Jiangsu Birth Cohort (JBC) were included in this study. Multiple linear regression models, generalized estimating equations (GEE), and weighted quantile sum (WQS) regression models were used to assess the associations between 24 urinary metal mass concentrations (adjusted for specific gravity, SG) during early pregnancy and offspring growth outcomes, including length/height for age Z score(HAZ), weight for age Z score(WAZ), weight for length/height Z score(WHZ), and head circumference for age Z score(HCAZ) at 1 and 3 years of age. Results: After adjusting for confounders, GEE analysis revealed that each natural log unit increase in maternal urinary concentrations of vanadium, tin, cerium, lead, and uranium during early pregnancy was associated with an average reduction in HCAZ by 14.29%, 4.82%, 2.62 %, 5.04 %, and 8.33%, respectively, at 1 and 3 years of age (FDR- P <0.05). Multiple linear regression analysis revealed that increased urinary vanadium concentration was associated with reduced HAZ at 1 year of age, while increased urinary concentrations of vanadium, chromium, tin, antimony, and uranium were associated with reduced HCAZ at 1 year of age (FDR- P <0.05). In the WQS regression model, each unit increase in the WQS index was associated with a 22.64% reduction in HCAZ at 1 year of age, with tin (22.2%) contributing the highest weight, followed by uranium (16.2%), lead (11.5%), vanadium (10.0%), arsenic (6.5%), and chromium (5.0%). Conclusions Prenatal exposure to specific metals and their mixtures may significantly impact the physical development of offspring at 1 and 3 years of age, particularly head circumference. These findings highlight the need to enhance monitoring of maternal metal exposure during early pregnancy to reduce the potential health risks posed by environmental metal pollution to infants and young children.