Toddler temperament and prenatal exposure to lead and maternal depression

Abstract

BackgroundTemperament is a psychological construct that reflects both personality and an infant’s reaction to social stimuli. It can be assessed early in life and is stable over time Temperament predicts many later life behaviors and illnesses, including impulsivity, emotional regulation and obesity. Early life exposure to neurotoxicants often results in developmental deficits in attention, social function, and IQ, but environmental predictors of infant temperament are largely unknown. We propose that prenatal exposure to both chemical and non-chemical environmental toxicants impacts the development of temperament, which can itself be used as a marker of risk for maladaptive neurobehavior in later life.In this study, we assessed associations among prenatal and early life exposure to lead, mercury, poverty, maternal depression and toddler temperament.MethodsA prospective cohort of women living in the Mexico City area were followed longitudinally beginning in the second trimester of pregnancy. Prenatal exposure to lead (blood, bone), mercury, and maternal depression were assessed repeatedly and the Toddler Temperament Scale (TTS) was completed when the child was 24 months old. The association between each measure of prenatal exposure and performance on individual TTS subscales was evaluated by multivariable linear regression. Latent profile analysis was used to classify subjects by TTS performance. Multinomial regression models were used to estimate the prospective association between prenatal exposures and TTS performance.Results500 mother-child pairs completed the TTS and had complete data on exposures and covariates. Three latent profiles were identified and categorized as predominantly difficult, intermediate, or easy temperament. Prenatal exposure to maternal depression predicted increasing probability of difficult toddler temperament. Maternal bone lead, a marker of cumulative exposure, also predicted difficult temperament. Prenatal lead exposure modified this association, suggesting that joint exposure in pregnancy to both was most toxic.ConclusionsMaternal depression predicts difficult temperament and concurrent prenatal exposure to maternal depression and lead predicts a more difficult temperament phenotype in 2 year olds. The role of temperament as an intermediate variable in the path from prenatal exposures to neurobehavioral deficits and other health effects deserves further study.

Cohort profile: the Neonatal Intensive Care Unit Hospital Exposures and Long-Term Health (NICU-HEALTH) cohort, a prospective preterm birth cohort in New York City

“…The LCA can be used as a single neurodevelopmental outcome in multinomial logistic regression modelling to reveal associations between NICU-based exposures and the latent class. As in our prior work,75 LCA can also facilitate probabilistic modelling of the association between a neurophenotype and concurrent NICU-based exposure to varying levels of multiple exposures.…”

Can broad-spectrum multinutrients treat symptoms of antenatal depression and anxiety and improve infant development? Study protocol of a double blind, randomized, controlled trial (the ‘NUTRIMUM’ trial)

“…Pregnancy and neonatal complications such as hypertension, preeclampsia, and gestational diabetes [ 8 ]; low birth weight, foetal growth restriction [ 9 , 10 ] and preterm birth [ 11 – 13 ] are more likely in individuals who experience antenatal depression and anxiety. Depression and anxiety during pregnancy have also been associated with poor cognitive, emotional and behavioural development of the infant [ 12 , 14 – 16 ], poor maternal attachment to the infant and increased risk of depression in partners [ 15 , 16 ].…”

Cross-sectional study of social behaviors in preschool children and exposure to flame retardants

“…Yet there is concern that chemicals commonly found in children’s environments may adversely influence social and emotional behavioral development [11]. For instance, epidemiological studies have reported that children with higher lead exposure have a greater probability of demonstrating negative social behaviors in toddlers, children, and young teens [12–14]. Exposure to bisphenol A (BPA), an endocrine disrupting chemical, has also been linked to behavioral outcomes in young children [15, 16].…”