Association between thyroid hormone levels and 4,4'-DDE concentrations in pregnant women (Valencia, Spain)

Environ Res. 2009 May;109(4):479-85. doi: 10.1016/j.envres.2009.02.003. Epub 2009 Mar 16.


Introduction: Several epidemiological studies have reported that some organochlorine compounds (OCs), such as polychlorobiphenyls (PCBs) and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4'-DDE), may alter thyroid function.

Objective: The aim of the present study was to investigate the association of maternal serum OC concentrations of 4,4'-DDE and the sum of seven PCB congeners (PCB 28, 52, 101, 118, 138, 153, and 180) with thyroid hormone (TH) status.

Methods: We measured OC concentrations in 157 maternal serum samples at 12 weeks of pregnancy in a cohort from Valencia (Spain). Thyroid-stimulating hormone (TSH), total triiodothyronine (TT3), and free thyroxine (FT4) were measured as biomarkers of thyroid function in the same samples. Linear and logistic regression analyses were performed between OCs and TH levels, and variables were log transformed.

Results: Mothers with higher levels of 4,4'-DDE had higher odds of having TSH levels >2.5 mIU/L (OR=2.53; 95% CI=1.36; 4.73; p=0.004), and we found a significant negative association between serum 4,4'-DDE concentrations and FT4 levels (beta=-0.03; 95% CI=-0.05; 0.00; p=0.050) after adjustment for covariates and total lipids. No association was found between sum of PCBs and TH levels.

Conclusion: Serum concentrations of 4,4'-DDE were associated with increased TSH and reduced FT4 but not TT3 levels. Our results suggest that some environmental chemicals may interfere with the thyroid system of pregnant women. The major role that maternal THs may play in fetal neurodevelopment makes these findings especially relevant.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Biomarkers / blood
  • Cohort Studies
  • Dichlorodiphenyl Dichloroethylene / adverse effects
  • Dichlorodiphenyl Dichloroethylene / blood*
  • Female
  • Fetal Development / drug effects*
  • Fetal Development / physiology
  • Humans
  • Insecticides / adverse effects
  • Insecticides / blood
  • Linear Models
  • Logistic Models
  • Maternal Exposure / adverse effects
  • Odds Ratio
  • Polychlorinated Biphenyls / adverse effects
  • Polychlorinated Biphenyls / blood*
  • Pregnancy
  • Pregnancy Trimester, First / blood
  • Prenatal Exposure Delayed Effects / blood*
  • Prenatal Exposure Delayed Effects / epidemiology
  • Spain / epidemiology
  • Thyroid Gland / drug effects*
  • Thyroid Gland / physiopathology
  • Thyroid Hormones / blood*
  • Thyroid Hormones / physiology
  • Thyrotropin / blood
  • Thyroxine / blood
  • Triiodothyronine / blood
  • Young Adult


  • Biomarkers
  • Insecticides
  • Thyroid Hormones
  • Triiodothyronine
  • Dichlorodiphenyl Dichloroethylene
  • Thyrotropin
  • Polychlorinated Biphenyls
  • Thyroxine