PBDE's are used as flame retardants in furniture, carpeting, textiles, electronics, and plastics. Commercial mixtures of PBDE's contain a variety of congeners [see http://en.wikipedia.org/wiki/Congeners]. Data collected by the Centers for Disease Control and Prevention suggest 97% of Americans may have detectable levels of PBDE's in their blood.
Researchers examined 223 pregnant women enrolled in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), a longitudinal birth cohort study focused on environmental exposures and reproductive health in California's Salinas Valley. Upon enrollment, the women reported their reproductive history, previous use of contraception and fertility medication, whether the pregnancy was planned, and how long it took to become pregnant after stopping contraception.
Blood samples collected around 26 weeks of pregnancy were analyzed for 10 PBDE congeners. Statistical analyses focused on those most commonly found: BDE-47, BDE-99, BDE-100, and BDE-153. BDE-100 and BDE-153 were the most strongly associated with longer time to pregnancy. For each month, the likelihood of becoming pregnant was 40% or 50% lower with a 10-fold increase in concentration of BDE-100 or -153, respectively. With a 10-fold increase in the total of all 4 congeners, there was a 30% decrease in the odds of pregnancy each month.
The study has several shortcomings, which the researchers recognize. For example, the study relied on self-reported time to pregnancy, which is subject to a number of biases. In addition, the study's findings are limited to 4 PBDE congeners, and thus may not extend to a broader population.
Given its shortcomings, the study suggests that at least some PBDE's may influence impact the time it takes to become pregnant.
The study can be found at http://ehsehplp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.0901450.