Maternal Exposure to Trace Elements, Toxic Metals, and Longitudinal Changes in Infancy Anthropometry and Growth Trajectories: A Prospective Cohort Study

Exploration of stage-specific effects of maternal exposureto traceelements and toxic metals on infancy continuous growth and trajectoriesis critical for early-life health management. Within a Chinese prospectivecohort in 2014-2015, a total of 919 mother-infant pairswere included, and the urinary levels of 17 elements including vanadium(V), chromium (Cr), manganese, iron, cobalt, nickel, copper, zinc,arsenic, molybdenum, palladium, cadmium, tin, gold, mercury, thallium,and lead in early (mean: 11.9 weeks), and late pregnancy (mean: 32.4weeks) were assessed. Standardized anthropometric assessments of infantswere conducted at 1, 3, 6, 8, and 12 months of age. A three-step longitudinaland high-dimensional data analysis procedure was carried out to estimatethe impacts of exposome on dynamic growth. Early-pregnancy exposuresto V and Cr were positively associated with repeated measurementsof length-for-age z-scores (LAZ). Six trajectorieswere identified based on LAZ. Maternal single exposure to V and Cras well as mixed exposure to trace elements in early pregnancy wereassociated with raised odds for the high-stable group. Our resultssuggested positive associations between maternal trace element exposomeand infancy dynamic growth. V and Cr were the key elements and theearly pregnancy might be the critical window. This study reported the key role of early-pregnancyexposureto V and Cr on longitudinal changes in infancy anthropometry and growthtrajectories, emphasizing the health management of pregnant women.