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Presentation Time: 4:25-4:45
Home University: UNC-Chapel Hill
Research Mentor: Dr. Gidi Shemer, Biology
Program: SMART
Research Title: Evaluating the Association Between Prenatal Toxic Metal Exposure and Placental DNA Methylation

Toxic metals belong to a major class of contaminants that are ubiquitously present in the environment, representing a threat to human health. Exposure to toxic metals during pregnancy has been linked to adverse outcomes at birth and later in life. During pregnancy, the placenta serves as a mediator between maternal and fetal exposures, as it enhances or reduces fetal exposure to toxicants. Thus, placental epigenetic change in response to metal exposure is important in understanding how such metals impact fetal development and birth outcomes. Here, we sought to evaluate the association between prenatal metal exposure and placental epigenetic marks (i.e placental clock alleles, metastable epialleles, and epigenetic aging). Placental DNA methylation was measured in 411 samples in the previously established Extremely Low Gestational Age Newborns (ELGAN) cohort using Illumina 850K DNA methylation array. Linear mixed effects models were fit to evaluate the overall associations between (1) epigenetic aging, (2) placental CpG sites annotated to clock, and (3) placental CpG sites annotated to metastable epialleles. All models were controlled for maternal smoking status, racism, body mass index, socioeconomic status, alcohol use, age, and gestational age based on their potential to confound associations among placental DNA methylation and metal exposure. These findings of the current study may help explain how metals cause adverse birth outcomes, specifically through modifying epigenetic aging and specific pathway(s) during development. Future studies should evaluate these associations in full term pregnancies.