Prenatal and early postnatal phthalate exposure and child neurodevelopment at age of 7 years – Polish Mother and Child Cohort

Abstract

Phthalates are among of the most frequently investigated environmental chemicals influencing children's health and particularly their neuropsychological development. However, the reported effects of these compounds on child behavior, cognitive and psychomotor outcome are not fully consistent. The aim of this study is to evaluate the associations between prenatal and early postnatal phthalate exposures and child neurodevelopment at age of 7 years. A total of 134 mother-child pairs from Polish Mother and Child cohort (REPRO_PL) constitute the basis for current analysis. Eleven phthalate metabolites were measured in urine samples collected from mothers in the 3 rd trimester of pregnancy and from children at the age of 2 years. Child neuropsychological development at early school age (7 years) was assessed by both the Strengths and Difficulties Questionnaire (SDQ) filled by mothers and the Polish adaptation of the Intelligence and Development Scales (IDS) performed by psychologists. MEP concentration during pregnancy was significantly associated with increased risk of peer relationship problems in SDQ (OR=2.7, p=0.03). The concentration of two phthalate metabolites (oxo-MEHP and MiBP) in the urine collected from mothers during pregnancy, as well as MnBP concentration at age of 2 years were of borderline significance on prosocial behaviour and hyperactivity/inattention problems, respectively (OR=2.6, p=0.08; OR=2.2, p=0.07; OR=2.6, p=0.08). The results of the IDS analyses focused on child's cognitive and psychomotor development are not fully conclusive. Negative associations were evident between some phthalates in early childhood period and fluid intelligence and cognition (MEP: β=-5.2; p=0.006; β=-4.2; p=0.006; MnBP: β=-4.9; p=0.03; β=-4.0; p=0.03; respectively) and psychomotor skills (OH-MiNP: β=-1.2; p=0.07), while positive associations have been found in the prenatal period (MEP: β=2.9; p=0.07 for cognition; β=1.4; p=0.06 for language skills; oxo-MEHP: β=3.6; p=0.03 for fluid intelligence; β=2.9; p=0.03 for cognition; β=1.2; p=0.08 for psychomotor development). Further studies are required in order to elucidate which are the most critical periods of phthalate exposure on children's neurodevelopmental outcomes.

Gestational Exposure to Phthalates and Social Responsiveness Scores in Children Using Quantile Regression: The EARLI and HOME Studies

“…Only when we assessed this relationship across percentiles of child SRS T-scores, did we observe associations of gestational MBP, MiBP, MCPP, MBzP, and ΣDEHP concentrations with SRS T-Scores in HOME. One potential reason for the discrepancy between our results and prior studies is that prior studies estimated associations at the mean of the outcome [34][35][36][37][38][39][40], and these individuals at the mean may be less susceptible compared to those at higher percentiles of SRS scores.…”

“…We too observed stronger associations for MBP, MiBP, MCPP in HOME. When we examined these associations using linear regression models in HOME, we observed modest (MBzP, MiBP, MCPP, and ΣDEHP), or null associations (MBP, MEP) with child SRS T-scores, which was consistent with some prior literature [34,35,40]. Only when we assessed this relationship across percentiles of child SRS T-scores, did we observe associations of gestational MBP, MiBP, MCPP, MBzP, and ΣDEHP concentrations with SRS T-Scores in HOME.…”

“…Previous reports have identified heterogeneity of the association between urinary phthalate concentrations and atypical social behaviors in childhood. While some studies have identified an inverse relationship between prenatal phthalate concentrations and behavior traits associated with Autism Spectrum Disorder (ASD) in childhood [34][35][36], others report null findings [37][38][39][40]. However, these inconsistent findings may depend on the source population and method of assessing ASD related traits, presence and potential of ASD related risk factors, and neurodevelopmental outcomes measured.…”

A Review of Recent Studies on Bisphenol A and Phthalate Exposures and Child Neurodevelopment

“…However, the opposite association was observed among boys [50]. Similarly, prenatal exposure to DBP and BBzP was significantly associated with language delay in children in the US and Sweden [53]. The adverse mental and psychomotor development of children in association with maternal exposure to DEHP was reported in a Korean study [52].…”

Similar names, different results: Consistency of the associations between prenatal exposure to phthalates and parent-ratings of behavior problems in preschool children

“…In preschool-aged children, higher maternal phthalate concentrations during pregnancy have been associated with higher internalizing (i.e., emotionally reactive, anxious/depressed, withdrawal) and externalizing (i.e., aggression, attention) problems ( Engel et al, 2010 ; Philippat et al, 2017 ; Whyatt et al, 2012 ). However, there have also been reports of null associations or positive associations between prenatal phthalate concentrations and child behavior outcomes ( Jankowska et al, 2019 ; Kobrosly et al, 2014 ; Whyatt et al, 2012 ). Less is known about potential sex-differences in neurobehavioral development following prenatal exposure to phthalates, but some research suggests that prenatal exposure may be associated with different behavioral problems in male children (i.e., aggression, attention, emotionally reactive) compared to female children (i.e., anxious/depressed) ( Engel et al, 2010 ; Kobrosly et al, 2014 ; Whyatt et al, 2012 ).…”