Plasticizers, Pregnancy, and Stress, Oh My! Stress Enhances Relationship Between Plastic Chemicals and Infant Neurodevelopment
Abstract
Prenatal exposure to phthalates, a group of synthetic chemicals widely used in everyday consumer products, has previously been associated with adverse infant and child neurodevelopment. Studies suggest that maternal exposure to psychosocial stressors, such as depression and anxiety, may amplify the harmful effects of phthalates on infant and child neurodevelopment. By understanding which factors lead to a healthy pregnancy, public health practitioners can intervene at critical periods in early development. Mother-child pairs (N=75) included in this analysis were a subset of those enrolled in the Atlanta African American Maternal-Child cohort. Eight phthalate metabolites were measured in first and second trimester maternal urine samples and had the geometric means calculated, as well as natural log transformed for analysis. Validated questionnaires administered during the first trimester were used to assess maternal depression and anxiety. The NICU Network Neurobehavioral Scale (NNNS) was administered at two weeks of age. Our primary outcomes included two composite NNNS scores reflecting newborn attention and arousal, defined using principal component analysis. Linear regression was used to estimate the effect of prenatal exposure to individual phthalates on newborn attention and arousal. We found that overall, higher levels of maternal prenatal urinary phthalate metabolites were associated with lower levels of infant attention and arousal and that these associations were strongest among those who experienced high levels of anxiety. We observed no evidence of effect modification by maternal depression. These results suggest that the adverse effect of phthalates on infant neurodevelopment may be exacerbated by maternal anxiety.
Keywords
: Research, Environmental Health, Epidemiology, Infant Development, Stress, Pregnancy
Plasticizers, Pregnancy, and Stress, Oh My! Stress Enhances Relationship Between Plastic Chemicals and Infant Neurodevelopment
Prenatal exposure to phthalates, a group of synthetic chemicals widely used in everyday consumer products, has previously been associated with adverse infant and child neurodevelopment. Studies suggest that maternal exposure to psychosocial stressors, such as depression and anxiety, may amplify the harmful effects of phthalates on infant and child neurodevelopment. By understanding which factors lead to a healthy pregnancy, public health practitioners can intervene at critical periods in early development. Mother-child pairs (N=75) included in this analysis were a subset of those enrolled in the Atlanta African American Maternal-Child cohort. Eight phthalate metabolites were measured in first and second trimester maternal urine samples and had the geometric means calculated, as well as natural log transformed for analysis. Validated questionnaires administered during the first trimester were used to assess maternal depression and anxiety. The NICU Network Neurobehavioral Scale (NNNS) was administered at two weeks of age. Our primary outcomes included two composite NNNS scores reflecting newborn attention and arousal, defined using principal component analysis. Linear regression was used to estimate the effect of prenatal exposure to individual phthalates on newborn attention and arousal. We found that overall, higher levels of maternal prenatal urinary phthalate metabolites were associated with lower levels of infant attention and arousal and that these associations were strongest among those who experienced high levels of anxiety. We observed no evidence of effect modification by maternal depression. These results suggest that the adverse effect of phthalates on infant neurodevelopment may be exacerbated by maternal anxiety.
