Search

Background: Toxic metals, such as lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg), may be associated with a higher risk of gestational hypertension and preeclampsia, whereas manganese (Mn) is an essential metal that may be protective. OBJECTIVES: We estimated the individual, independent, and joint associations of Pb, Cd, As, Hg, and Mn on the risk of developing gestational hypertension and preeclampsia in a cohort of Canadian women. Methods: Metal concentrations were analyzed in first and third trimester maternal blood (n = 1,560). We measured blood pressure after 20 wk gestation to diagnose gestational hypertension, whereas proteinuria and other complications defined preeclampsia. We estimated individual and independent (adjusted for coexposure) relative risks (RRs) for each doubling of metal concentrations and examined interactions between toxic metals and Mn. We used quantile g-computation to estimate the joint effect of trimester-specific exposures. Results: Each doubling of third trimester Pb (RR = 1.54; 95% CI: 1.06, 2.22) and first trimester blood As (RR = 1.25; 95% CI: 1.01, 1.58) was independently associated with a higher risk of developing preeclampsia. First trimester blood As (RR = 3.40; 95% CI: 1.40, 8.28) and Mn (RR = 0.63; 95% CI: 0.42, 0.94) concentrations were associated with a higher and lower risk, respectively, of developing gestational hypertension. Mn modified the association with As such that the deleterious association with As was stronger at lower concentrations of Mn. First trimester urinary dimethylarsinic acid concentrations were not associated with gestational hypertension (RR=1.31; 95% CI: 0.60, 2.85) or preeclampsia (RR = 0.92; 95% CI: 0.68, 1.24). We did not observe overall joint effects for blood metals. Discussion: Our results confirm that even low blood Pb concentrations are a risk factor for preeclampsia. Women with higher blood As concentrations combined with lower Mn in early pregnancy were more likely to develop gestational hypertension. These pregnancy complications impact maternal and neonatal health. Understanding the contribution of toxic metals and Mn is of public health importance. https://doi.org/10.1289/EHP10825, Introduction Gestational hypertension and preeclampsia are major contributors to maternal (1,2) and newborn (3,4) morbidity and mortality. Women with these conditions have an increased risk of developing hypertension and other [...]

Background: The etiology of autism spectrum disorder is poorly understood. Few studies have investigated the link between endocrine-disrupting chemicals and autistic traits. We examined the relationship between gestational phthalates and autistic traits in 3- to 4-y-old Canadian children. We also investigated potential effect modification by sex and folic acid supplementation. Methods: We enrolled 2,001 women > 18 years of age during the first trimester of pregnancy between 2008 and 2011 from 10 cities in Canada. At 3-4 years of age, 610 children underwent neuropsychological assessments including the Social Responsiveness Scale-II (SRS-2) as a measure of autistic traits and social impairment. We measured 11 phthalate metabolites in maternal first trimester urine samples and assessed folic acid supplementation from reported intakes. We estimated covariate-adjusted differences in SRS-2 T-scores with a doubling in phthalate concentrations in 510 children with complete data. Results: Mean total SRS T-score was 45.3 (SD = 6.1). Children with higher gestational exposure to mono-n-butyl (MBP) and mono-3-carboxypropyl (MCPP) concentrations exhibited significantly higher total SRS T-scores, indicating greater overall social impairment, as well as higher scores on subdomains, indicating deficits in social cognition, social communication, social motivation, and restricted interests/repetitive behaviors. A doubling in MBP or MCPP concentrations was associated with 0.6 (95% CI: 0.1, 1.0) and 0.5 (95% CI: 0.1, 0.8) higher total SRS T-scores. Associations were consistently and significantly stronger in boys ([[beta].sub.MBP] = 1.0; 95% CI: 0.4, 1.6; n = 252) compared with girls ([[beta].sub.MBP] = 0.1; 95% CI: -0.6, 0.7; n = 258) and among children who had lower prenatal folic acid supplementation ( Conclusions: Higher gestational concentrations of some phthalate metabolites were associated with higher scores of autistic traits as measured by the SRS-2 in boys, but not girls; these small size effects were mitigated by first trimester-of-pregnancy folic acid supplementation., Background Autism Spectrum Disorder (ASD), which affects about 1.7% of children (Baio et al. 2018), comprises a complex group of brain-based disorders characterized by social deficits, atypical communication, and repetitive [...]

Fetal and child development are shaped by early life exposures, including maternal health states, nutrition and educational and home environments. We aimed to determine if suboptimal pre-pregnancy maternal body mass index (BMI; underweight, overweight, obese) would associate with poorer cognitive outcomes in children, and whether early life nutritional, educational and home environments modify these relationships. Self-reported data were obtained from mother-infant dyads from the pan-Canadian prospective Maternal-Infant Research on Environmental Chemicals cohort. Relationships between potential risk factors (pre-pregnancy maternal BMI, breastfeeding practices and Home Observation Measurement of the Environment [HOME] score) and child cognitive development at age three (Weschler's Preschool and Primary Scale of Intelligence, Third Edition scale and its subcategories) were each evaluated using analysis of variance, multivariable regression models and moderating analyses. Amongst the 528 mother−child dyads, increasing maternal pre-pregnancy BMI was negatively associated with scores for child full-scale IQ (β [95% CI]; −2.01 [−3.43, −0.59], p = 0.006), verbal composite (−1.93 [−3.33, −0.53], p = 0.007), and information scale (−0.41 [−0.70, −0.14], p = 0.003) scores. Higher maternal education level or HOME score attenuated the negative association between maternal pre-pregnancy BMI and child cognitive outcome by 30%–41% and 7%–22%, respectively, and accounted for approximately 5%–10% greater variation in male children's cognitive scores compared to females. Maternal education and higher quality home environment buffer the negative effect of elevated maternal pre-pregnancy BMI on child cognitive outcomes. Findings suggest that relationships between maternal, social and environmental factors must be considered to reveal pathways that shape risk for, and resiliency against, suboptimal cognitive outcomes in early life. [ABSTRACT FROM AUTHOR]