February 3, 2010
NEW YORK (Reuters Health) – Having difficulty getting pregnant? Perhaps your sofa is to blame. Or your stereo or carpet or any of the things in your house that contain common flame-retardant chemicals known as PBDEs that a new study suggests may be associated with decreased fertility.
In a study in the latest issue of Environmental Health Perspectives, researchers found that, for each 10-fold increase in PBDE blood concentration, women experience a 30 percent decrease in the odds of getting pregnant each month.
PBDEs have been associated with reproductive and hormonal effects in animals, but this is the first study to examine their association with human fertility, lead researcher Dr. Kim G. Harley of the Center for Children’s Environmental Health Research at U.C. Berkeley’s School of Public Health in California and colleagues note in their report.
The researchers measured PBDE levels in blood samples from 223 pregnant women enrolled in a long-term study examining environmental exposures and reproductive health. The investigators also asked the women how many months it had taken them to become pregnant.
They found that women with the highest blood concentrations of PBDE took the longest to become pregnant — up to 12 months. The study cut off at 13 months. In addition, the 107 women who were actively trying to become pregnant were half as likely to conceive in any given month if they had high levels of PBDE in their blood.
Experts say most women become pregnant within the first six months of trying. After 12 months of trying with no pregnancy, women will be classified as “infertile,” Harley added, even though they will likely go on to conceive after that. After 12 months of unprotected intercourse, roughly 85 percent of women younger than age 35 will become pregnant, while half of women older than 35 will. Infertility treatment typically doesn’t start until a couple has been trying for a year, with no luck.