Early Gestational Exposure to High-Molecular-Weight Phthalates and Its Association with 48-Month-Old Children’s Motor and Cognitive Scores

Libni A Torres-Olascoaga,John D Meeker,Maritsa Solano-Gonzalez,Karen E Peterson,Lourdes Schnaas,Marcela Tamayo-Ortiz,Martha María Tellez-Rojo,Deborah Watkins,Erika Osorio-Valencia

doi:10.3390/ijerph17218150

Abstract

In utero phthalate exposure has been associated with neurodevelopmental disorders, nevertheless, trimester-specific susceptibility remains understudied. Our aim was to identify susceptible windows to the effects of gestational High-Molecular-Weight Phthalates (HMWP) exposure on 48 months’ neurodevelopment. We measured six HMWP metabolites (MEHP, MEHHP, MEOHP, MECPP, MBzP and MCPP) in urine samples collected during each trimester from women in the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) cohort (n = 218). We assessed children’s motor (MS), cognitive (GCI) and memory (MeS) abilities using McCarthy Scales of Children’s Abilities (MSCA). We used linear regression models to examine associations between trimester-specific phthalate metabolites and MSCA scores, adjusted for sex, gestational age, breastfeeding, and maternal IQ. Although phthalate concentrations were similar across trimesters, first and second trimester phthalates were inversely associated with MS and GCI, with first trimester associations with MS being the strongest and statistically significant. Stronger associations were seen with MS and GCI among boys compared to girls, however interaction terms were not statistically significant. Our results suggest that early gestation is a sensitive window of exposure to HMWP for neurodevelopment, particularly in boys. Regulations on phthalate content in food as well as pregnancy consumption guidelines are necessary to protect future generations.

Highlights

Neurodevelopment is a critical life process, beginning in utero and ending in adolescence [1].Identifying risk factors for neurodevelopment at the earliest possible life stages is of high public health relevance since long-term effects of neurodevelopment can impact an individual’s life, and, at a population level, can translate into economic loss for a country [2]
Phthalates were classified into two groups based on molecular weight and typical sources of exposure: For the present analysis we focused on the High-Molecular-Weight Phthalates (HMWP)
We found a negative and significant association for the first trimester phthalates and most of the metabolites with motor scale (MS), which was consistent for the second trimester

Summary

Introduction

Neurodevelopment is a critical life process, beginning in utero and ending in adolescence [1]. Identifying risk factors for neurodevelopment at the earliest possible life stages is of high public health relevance since long-term effects of neurodevelopment can impact an individual’s life, and, at a population level, can translate into economic loss for a country [2]. Gestational exposure to endocrine disruptors, such as phthalates has been increasingly associated with neurodevelopment. Res. Public Health 2020, 17, 8150; doi:10.3390/ijerph17218150 www.mdpi.com/journal/ijerph

Objectives

Methods

Results

Conclusion