New study—flame retardant risks to pregnant women and babies

Normal thyroid hormone levels in pregnant mothers are essential for fetal growth and brain development. New findings from the University of California suggest that exposure to common flame retardants is lowering the levels of these hormones in pregnant women. As part of a large, long-term study of environmental exposures and reproductive health, the researchers analyzed blood samples from 270 pregnant women taken around the end of their second trimester. What they found may represent a public health problem, the scientists say. The chemical flame retardants most frequently detected --PBDEs-- were associated with significant decreases in the expectant mothers' thyroid-specific hormone (TSH) levels. These changes "...are an indication of subclinical hyperthyroidism, which is often the first step leading toward clinical hyperthyroidism," said the study’s lead author, Jonathan Chevrier, a UC Berkeley researcher. "....Maternal clinical hyperthyroidism is linked to altered fetal neurodevelopment, increased risk of miscarriage, premature birth and intrauterine growth retardation."