Does exposure to flame retardants increase the risk for preterm birth?

During the past 40 years, polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants and nearly all women have some level of exposure. PBDEs have been isolated from amniotic fluid and cord plasma indicating vertical transmission; however, their effects on pregnancy outcome are largely unknown. Therefore, we quantified PBDE-47, the most common congener in maternal plasma samples collected at the time of labor from women who subsequently had term or preterm birth (PTB). Women were then scored based on whether or not they had very low, low, medium, high or very high peripheral plasma concentrations of PBDE-47. Probit regression analysis suggested that women in the PTB group had a greater chance of scoring higher on this scale (P<0.001). Women with high (OR=3.8, CI: 1.6, 9.7; P=0.003) or very high PBDE-47 concentrations were at greater odds (OR=5.6, CI: 2.2, 15.2; P<0.001) for PTB than women with very low levels of PBDE-47. Results became even more significant after adjustment for maternal race, age, and marital status. These findings suggest that high levels of maternal exposure to PBDEs might increase the risk for PTB.