Combined Exposure to Folate and Lead during Pregnancy and Autistic-Like Behaviors among Canadian Children from the MIREC Pregnancy and Birth Cohort.

Background: Folic acid (FA) supplementation may attenuate the associations between gestational exposure to certain chemicals and autism or autistic-like behaviors, but to our knowledge, this has not been assessed for lead.

Objectives: We examined whether the relationship between gestational blood-lead levels (BLLs) and autistic-like behaviors was modified by gestational plasma total folate concentrations, FA supplementation, and maternal methylenetetrahydrofolate reductase () 677C>T genotype.

Methods: We used data from the Maternal-Infant Research on Environmental Chemicals study (2008-2011), a Canadian pregnancy and birth cohort study.

Gestational exposure to organochlorine compounds and metals and infant birth weight: effect modification by maternal hardships.

Background: Gestational exposure to toxic environmental chemicals and maternal social hardships are individually associated with impaired fetal growth, but it is unclear whether the effects of environmental chemical exposure on infant birth weight are modified by maternal hardships.

Methods: We used data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a pan-Canadian cohort of 1982 pregnant females enrolled between 2008 and 2011. We quantified eleven environmental chemical concentrations from two chemical classes - six organochlorine compounds (OCs) and five metals - that were detected in ≥ 70% of blood samples collected during the first trimester.

Effects of gestational exposures to chemical mixtures on birth weight using Bayesian factor analysis in the Health Outcome and Measures of Environment (HOME) Study.

Unlabelled: Studying the effects of gestational exposures to chemical mixtures on infant birth weight is inconclusive due to several challenges. One of the challenges is which statistical methods to rely on. Bayesian factor analysis (BFA), which has not been utilized for chemical mixtures, has advantages in variance reduction and model interpretation.

Prenatal exposure to endocrine disrupting chemical mixtures and infant birth weight: A Bayesian analysis using kernel machine regression.

Background: Pregnant women are regularly exposed to a multitude of endocrine disrupting chemicals (EDCs). EDC exposures, both individually and as mixtures, may affect fetal growth. The relationship of EDC mixtures with infant birth weight, however, remains poorly understood.

Associations of prenatal urinary phthalate exposure with preterm birth: the Maternal-Infant Research on Environmental Chemicals (MIREC) Study.

Objectives: To examine the relation between prenatal urinary phthalate metabolite concentrations and preterm birth (PTB).

Methods: The data were drawn from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a pan-Canadian cohort of 1857 pregnant women enrolled between 2008 and 2011. We quantified urinary concentrations of 7 phthalate metabolites that were detected in > 70% of urine samples collected during the first trimester.