Umbilical cord Metals concentration and Neurodevelopment in a birth cohort - Pipa Project - Rio de Janeiro - Brazil

Abstract

The world population, in general, is simultaneously exposed to various metals that can affect children’s neurodevelopment. Aims: Analyze the association between metal concentrations in umbilical cord blood and the child's neurodevelopment up to the sixth month old. Methods: A pilot study was conducted from October 2017 to August 2018, at the Maternity School of the Federal University of Rio de Janeiro, Brazil. Infant’s neurodevelopment was evaluated using Denver Developmental Screening Test II (Denver-II) at six months old. The neurodevelopment assessment considered the conclusions according to the test criteria and the proportion of failure according to the test analysis fields. Exposure was assessed for lead (Pb), Arsenium (AS), Mercury (Hg) and Cadmium (Cd) based on tertiles. Results: 135 babies participated in the cohort, 58 attended the 6 month follow-up and among these 5.17% were considered suspected according to the classification criteria for neurodevelopment of DENVER II. The analysis of the occurrence of failures showed a total of 31.7%, 4.8% in personal social development, 4.8% fine motor, 4.8% language and 19.5% gross motor. The concentration of metals in the umbilical cord blood, classified by tertile, did not show a clear association for lead (RR = 0.735 95% CI - 0.199 - 2.714) and mercury (RR = 0.59 95% CI 0.191 - 1.828). Arsenic and cadmium showed an association with the proportion of failures only in the first month of follow-up, with RR = 6.26 (0.856 - 45.85) when comparing the second tertile of AS with the first (reference). And the Cd RR = 0.18 CI 95% 0.024 - 1.298). New studies with a greater number of follow-ups are needed to reinforce the rejection of such notes. The PIPA Project cohort will start in the year 2020 and allow greater power of analysis.