Prenatal Exposure to Flame Retardants Disrupts Fetal Thyroid Hormone in Sex-Specific Ways

Strategic Insights -

Research from Shanghai Institute for Biomedical and Pharmaceutical Technologies has shed light on the potential risks of prenatal exposure to flame retardants on fetal thyroid hormone. According to a study published in Ecotoxicology and Environmental Safety, exposure to organophosphate esters (OPEs) and polybrominated diphenyl ethers (PBDEs) during early pregnancy can disrupt fetal thyroid hormone, with sex-specific differences in DNA methylation patterns. The study analyzed OPE metabolite concentrations in maternal urine and PBDE levels in cord plasma, revealing associations between prenatal exposure and DNA methylation of placental thyroid hormone-related genes.

Key Takeaways:

  • Prenatal exposure to organophosphate esters (OPEs) and polybrominated diphenyl ethers (PBDEs) has been linked to disrupted fetal thyroid hormone.
  • Sex-specific differences in DNA methylation patterns were observed in placental thyroid hormone-related genes in relation to PBDE and OPE exposure.
  • OPE metabolites were positively associated with DIO3 and TTR methylation in females.
  • PBDEs showed sex-specific relationships with DIO3 and SLC16A2 methylation, with a significant positive association in females and a non-significant inverse association in males.
  • Mediation analyses suggested that SLCO1C1 hypermethylation mediated 6.5-7.0% of the association between SPBDE exposure and reduced free triiodothyronine.

Statistics:

  • 240 mother-newborn pairs were analyzed for OPE exposure and DNA methylation of placental thyroid hormone-related genes.
  • 327 mother-newborn pairs were analyzed for PBDE exposure and DNA methylation of placental thyroid hormone-related genes.
  • 6.5-7.0% of the association between SPBDE exposure and reduced free triiodothyronine was mediated by SLCO1C1 hypermethylation.

Sources:

  • Sex-specific DNA methylation changes in placental thyroid hormone regulatory genes following prenatal exposure to flame retardants. Ecotoxicology and Environmental Safety, 2025;303:118840.
  • Shanghai Institute for Biomedical and Pharmaceutical Technologies, Shanghai 200237, People's Republic of China.
  • Academic Press Inc Elsevier Science, 525 B St, Ste 1900, San Diego, CA 92101-4495, USA.