Environment/Climate Change
Maternal Early-pregnancy and Newborn Prenatal Exposure to Hg, Mn, Se and Zn and Child Neurodevelopment Development in the First 24 Months: A Prospective Cohort Study Fengxiu Ouyang* Fengxiu Ouyang Ting Zhang Yichun Xuan Yanlin Li Jinqian Ma Junxia Liu Chong-Huai Yan Jun Zhang
There is limited information on the joint effect of multiple-metal(loid)s on infant development. This study aimed to investigate the joint impact of early pregnancy and newborn exposures to mercury (Hg), selenium (Se), manganese (Mn) and zinc (Zn) on child neurodevelopment in the first 24 months. Included were 2771 mother-infant pairs from the Shanghai Birth cohort who had Hg, Mn, Se and Zn measured in early pregnancy maternal and cord blood samples. These elements were analyzed as both categorical in tertiles and log-transformed continious variables. Neurobehavior was assessed using the Ages and Stages Questionnaire, 3rd edition (ASQ-3) and the ASQ: Social-Emotional (SE) instrument at the age of 6 months, and Bayley Scales of Infant & Toddler Development, 3rd edition (BSID-III) at the age of 24 months. Using multiple linear regression, maternal blood Hg levels > 2.09μg/L were associated with 1.78 points higher ASQ:SE scores (95%CI: 0.22, 3.33; P < 0.05), and 1.20 points lower ASQ-3 communication scores (95%CI: -2.06, -0.35; P 5.62μg/L was associated with 2.74 points higher cognition score (95%CI 0.53, 4.94; p<0.05) at age 24 months. Similar results were observed by using Bayesian kernel machine regression (BKMR) with the four elements adjusted for each other. Overall, the maternal blood metal mixture was negatively associated with infant ASQ-3 communication scores at the age of 6 months, with Mn being identified as the dominant (cond PIP = 0.998) element with an inverse “U” shape association. Associations between maternal blood metal mixtures of Hg, Mn, Se and Zn with infant 24 months outcomes were found not significant. Our study findings suggest that maternal blood Hg concentrations, and the metal mixture in early pregnancy adversely impact infant neurobehavior development at the age of 6 months.