<p>Intrauterine development represents a critical life stage and is highly susceptible to environmental pollutants. Any disruptions during this period can lead to various poor birth outcomes. This cohort study enrolled 493 mother-newborn pairs from southern China and quantified maternal serum levels of nine essential and non-essential trace elements. Quantile-based g-computation (QGC) and Bayesian kernel machine regression (BKMR) were applied to evaluate the joint effects of metal mixture on neonatal birth outcomes and maternal metabolic health. QGC model showed that prenatal exposure to metal mixture was inversely associated with neonatal birth weight (<i>β</i> = −&#xa0;59.8, <i>P</i> = 0.007), birth length (<i>β</i> = −&#xa0;0.23, <i>P</i> = 0.018), head circumference (<i>β</i> = −&#xa0;0.16, <i>P</i> = 0.026), and chest circumference (<i>β</i> = −&#xa0;0.16, <i>P</i> = 0.048). The negative relationship between metals and gestational age (<i>β</i> = −&#xa0;0.21, <i>P</i> = 0.006) was also observed. As and Co were characterized as the major contributors to the overall effect of the mixture on birth outcomes. Besides, increased metal levels correlated with decreased maternal free thyroxine (FT4) and elevated lipid levels. Of note, sex-specific and trimester-specific effects of metal mixture on fetal growth parameters were identified, indicating that the mixture-outcome links were more pronounced or exclusively occurred in male offspring and pregnant women during their second trimester. Further efforts need to focus on comprehensive exposure assessment to capture a more complete picture of prenatal exposures, as well as the underlying mechanisms.</p> Graphical Abstract <p></p>