Influence of Prenatal Lead Exposure on Genomic Methylation of Cord Blood DNA

This study aims to determine if prenatal lead exposure leads to alterations in the epigenome of the developing fetus. Data suggest the mother’s current and past lead burden may have long-term influence on the developing epigenome and on disease susceptibility throughout the life course.

Fetal lead exposure is associated with adverse pregnancy outcomes and developmental and cognitive deficits, yet the mechanisms remain unknown. In this study, researchers examined the associations between maternal lead burden and genomic DNA methylation levels, as assessed by Alu and LINE-1 methylation via pyrosequencing. Levels were measured using 103 umbilical cord blood samples from the Early Life Exposures in Mexico to Environmental Toxicants study group. Maternal bone lead levels at the midtibial shaft and the patella were used to measure prenatal lead exposure.

Key Findings:

  • Prenatal lead exposure is inversely associated with genomic DNA methylation in cord blood.
  • In mixed effects regression models, maternal tibia lead was negatively associated with umbilical cord genomic DNA methylation of Alu.
  • No associations were found between cord blood lead and cord genomic DNA methylation.

This study of epigenitics provides evidence of how early life events and environmental risk factors may impact human populations.