BPA effects Thyroid Hormone Levels During Pregnancy and in Newborns

Article by Naturalmedicine.com

More reason to stay away from BPAwhenever you can especially from kids.

New research finds that bisphenol A (BPA), an estrogen-like compound has been linked to changes in thyroid hormone levels in pregnant women and newborn boys.

The research comes from according to a new study by researchers at the University of California, Berkeley.

Normal thyroid function is essential to the healthy growth and cognitive development of fetuses and children. Yet, until this study, little was known about the effects of BPA exposure on thyroid hormones in pregnant womenand newborns.

The new findings add to the wide spread concerns about BPA, a chemical found in hard plastics, linings of canned food, dental sealants, and sales receipts on thermal paper, which is coated with a chemical that changes color when exposed to heat.

BPA Concerns Grow

In July, the U.S. Food and Drug Administration officially banned the chemical in baby bottles and cups, something the industry began doing voluntarily in recent years in response to consumer concerns about the potential risks of BPA.

The researchers analyzed BPA levels in the urine samples of 335 women during the second half of pregnancy, and thyroid hormone levels in blood samples taken from the mothers during pregnancy and from the newborns within a few days of birth. The participants were part of the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study led by Brenda Eskenazi, UC Berkeley professor of epidemiology and of maternal and child health.

Significant Increase in BPA Levels
The researchers found that for each doubling of BPA levels, there was an associated decrease of 0.13 micrograms per deciliter of total thyroxine (T4) in mothers during pregnancy, which suggests a hypothyroid effect. For newborn boys, each doubling of BPA levels linked to a 9.9 percent decrease in thyroid stimulating hormone (TSH), indicating a hyperthyroid effect.

“Most of the women and newborns in our study had thyroid hormone levels within a normal range, but when we consider the impact of these results at a population level, we get concerned about a shift in the distribution that would affect those on the borderline,” said study lead author Jonathan Chevrier, research epidemiologist at UC Berkeley’s Center for Environmental Research and Children’s Health (CERCH). “In addition, studies suggest that small changes in thyroid level, even if they’re within normal limits, may still have a cognitive effect.”

Impact on Child’s Development
The researchers pointed out that several studies in recent years have linked lower thyroid hormone levels to delays in cognitive and motor development in young children. Two years ago, the same group of UC Berkeley researchers also found links between PBDEs (polybrominated diphenyl ethers), a class of flame retardants, and changes in thyroid hormone levels.

They were confident that the BPA was acting on thyroid hormones independently from PBDEs, because levels of the two compounds were not correlated.

“There is good reason to be concerned about PBDEs and BPA, because both of these compounds are ubiquitous in our environment,” said Harley. “More than 90 percent of women of reproductive age have detectable levels of BPA in their urine, and some 97 percent of U.S. residents have detectable levels of PBDEs in their blood. Until we learn more about the human health effects of these chemicals, it would make sense to be cautious and avoid exposure when possible, particularly for those who are pregnant.”