Toddler temperament and prenatal exposure to lead and maternal depression

Background: Temperament 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. Methods: A 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. Results: 500 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. Conclusions: Maternal 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

Neonatal Intensive Care Unit Phthalate Exposure and Preterm Infant Neurobehavioral Performance

Every year in the United States, more than 300,000 infants are admitted to neonatal intensive care units (NICU) where they are exposed to a chemical-intensive hospital environment during a developmentally vulnerable period. The neurodevelopmental impact of environmental exposure to phthalates during the NICU stay is unknown. As phthalate exposure during the third trimester developmental window has been implicated in neurobehavioral deficits in term-born children that are strikingly similar to a phenotype of neurobehavioral morbidity common among children born premature, the role of early-life phthalate exposure on the neurodevelopmental trajectory of premature infants may be clinically important. In this study, premature newborns with birth weight less than 1500g were recruited to participate in a prospective environmental health cohort study, NICU-HEALTH (Hospital Exposures and Long-Term Health), part of the DINE (Developmental Impact of NICU Exposures) cohort of the ECHO (Environmental influences on Child Health Outcomes) program. These two files contain urinary phthalate biomarker levels and NICU Network Neurobehavioral Scale assessment scores for this cohort

Congenital Malformations in the Newborn Population: A Population Study and Analysis of the Effect of Sex and Prematurity

Congenital malformation (CM) is a leading cause of infant mortality. We hypothesized that the current estimates of the prevalence of CM are obsolete because of the increased rate of terminating fetuses with severe CMs and the widespread use of prenatal vitamins. Methods: This population-based cross-sectional study analyzed the effect of sex and prematurity on CM prevalence. All data were derived from birth entries in the 2008 Nationwide Inpatient Sample (NIS) database. Our objectives were to determine the prevalence of CM diagnoses among all birth hospitalizations in 2008 and to analyze the effect of sex and gestational maturity on CM prevalence. Results: We identified 29,312 patients with CMs from among 1,014,261 live births, which yielded a CM prevalence of 28.9 per 1000 live births. Associated genetic syndromes were present in 1172 (4%) patients. Among newborns with nonsyndromic CM, 91% of newborns had an isolated CM and 9% of newborns had multiple CMs. The cardiovascular system was the most commonly involved organ system. The risk of CM was significantly higher in preterm newborns for an isolated CM [odds ratio (OR), 1.5; confidence interval (CI), 1.4–1.5]; multiple CMs (OR, 2.1; CI, 2.0–2.3); and overall CMs (OR, 1.4; CI, 1.3–1.5). Males had higher risk of isolated CMs (OR, 1.3; CI, 1.2–1.5). However, there was no sex difference in the risk of overall CM. Conclusion: We reported up-to-date national estimates of the prevalence of CM, which is important for monitoring trends, determining service planning, and assessing disease burden because of congenital malformations in the United States of America. We also showed a strong association between CM and prematurity. Further study of this association is needed to provide insight into the etiology of these relatively common public health problems

Association of Preterm Birth with Risk of Ischemic Heart Disease in Adulthood

Importance: Preterm birth has previously been associated with increased risks of hypertension and diabetes, but not ischemic heart disease (IHD), in adulthood. The reasons for this lack of association with IHD despite associations with its risk factors have been elusive, but may be associated with methodologic issues, such as survivor bias, in prior studies. Objective: To determine whether preterm birth is associated with an increased risk of IHD in adulthood in a large population-based cohort. Design, Setting, and Participants: This national, population-based cohort study included all 2141709 persons who were born as singleton live births in Sweden during 1973 to 1994. The data were analyzed in September 2018. Exposures: Gestational age at birth, identified from nationwide birth records in the Swedish Birth Registry. Main Outcomes and Measures: Ischemic heart disease that was identified from nationwide inpatient and outpatient diagnoses through 2015 (maximum age, 43 years). A Cox regression was used to examine gestational age at birth in association with IHD in adulthood while adjusting for other perinatal and maternal factors. Cosibling analyses assessed for potential confounding by unmeasured shared familial factors. Results: Of 2141709 participants, 1041906 (48.6%) were female and there were 1921 persons (0.09%) who received a diagnosis of IHD in 30.9 million person-years of follow-up. Gestational age at birth was inversely associated with IHD risk in adulthood. At ages 30 to 43 years, adjusted hazard ratios for IHD associated with preterm (gestational age <37 weeks) and early-term birth (37-38 weeks) were 1.53 (95% CI, 1.20-1.94) and 1.19 (1.01-1.40), respectively, compared with full-term birth (39-41 weeks). Preterm-born women had lower IHD incidence than preterm-born men (15.16 vs 22.00 per 100000 person-years) but had a higher adjusted hazard ratio (1.93; 95% CI, 1.28-2.90 vs 1.37; 95% CI, 1.01-1.84). These associations did not appear to be explained by shared genetic or environmental factors in families. Conclusions and Relevance: In this large national cohort, preterm and early-term birth were associated with an increased IHD risk in adulthood. Persons born prematurely need early evaluation and preventive actions to reduce the risk of IHD