Micronutrients during pregnancy and child psychomotor development: Opposite effects of Zinc and Selenium

Studies on the impact of micronutrient levels during different pregnancy periods on child psychomotor functions are limited. The aim of this study was to evaluate the association between maternal plasma concentrations of selected micronutrients, such as: copper (Cu), zinc (Zn), selenium (Se), and child neuropsychological development. The study population consisted of 539 mother-child pairs from Polish Mother and Child Cohort (REPRO_PL). The micronutrient levels were measured in each trimester of pregnancy, at delivery and in the cord blood. Psychomotor development was assessed in children at the age of 1 and 2 years using the Bayley Scales of Infant and Toddler Development. The mean plasma Zn, Cu and Se concentrations in the 1st trimester of pregnancy were 0.91 +/- 0.27 mg/l, 1.98 +/- 0.57 mg/l and 48.35 10.54 mu g/l, respectively. There were no statistically significant associations between Cu levels and any of the analyzed domains of child development. A positive association was observed between Se level in the 1st trimester of pregnancy and child language and motor skills (beta=0.18, p =0.03 and beta=0.25, p=0.005, respectively) at one year of age. Motor score among one-year old children decreased along with increasing Zn levels in the 1st trimester of pregnancy and in the cord blood (beta= -12.07, p = 0.003 and beta= -6.51, p = 0.03, respectively). A similar pattern was observed for the association between Zn level in the 1st trimester of pregnancy and language abilities at one year of age (beta= 7.37, p = 0.05). Prenatal Zn and Se status was associated with lower and higher child psychomotor abilities, respectively, within the first year of life. Further epidemiological and preclinical studies are necessary to confirm the associations between micronutrient levels and child development as well as to elucidate the underlying mechanisms of their effects.