BPA Influences Thyroid Function in Pregnant Women and Newborns
According to a new study led by researchers at the University of California, Berkeley, BPA (bisphenol A) is associated with decreased levels of thyroid hormone in pregnant women and newborns. The study was published in the journal Environmental Health Perspectives, and reveals the effects of exposure to bisphenol in pregnant women and newborns. These effects in thyroid function may lead to cognitive and motor development disorders in young children.
Thyroid hormones, released by the thyroid gland, have many roles in the body. It should be noted that the thyroid is affected by pituitary thyroid-stimulating releasing hormone (TSH). Also, the pituitary gland is in turn influenced by the hypothalamus that releases thyroid releasing hormone (TRH). Thyroxine (T4) and triiiodotironin (T3) have an important role both in fetal life and after birth. Thyroid hormones are involved in the development and differentiation of cells in the body. In addition to neuronal development and maturation, hormones released by the thyroid gland have a role in regulating protein, lipid and carbohydrate metabolism. TSH and TRH secretion begin in fetal life from week 18-20 of pregnancy.
Now researchers at the University of California, Berkeley, found that exposure to bisphenol A affects thyroid hormone levels in both pregnant women and neonates. Studies on the effects of bisphenol exposure have been made in the past. Bisphenol is a compound found in plastics, such as bottles, cans, etc.. Concerns about this chemical began several years ago when it was discovered that bisphenol is harmful in children. Therefore, the use of this compound has been banned in baby bottles. It seems that bisphenol has multiple health effects: endocrine disorders, obesity, neurological disorders, some studies have associated bisphenol with certain cancers.
To see the effects of BPA on thyroid function, researchers conducted a study that included 335 women. They did more tests and measured the levels of BPA in urine and thyroid hormone levels in both pregnant and newborns in the first days of life. The researchers found that the more exposure to bisphenol was higher the more this affected thyroid function. There was a decrease by 0.13 micrograms per deciliter of thyroxine for each doubling of BPA levels. This decrease means hypothyroidism.
In addition, in male infants it was found that doubling the level of BPA lead to a decrease of 9.9% of TSH. It is still not clear why this effect occurs only in male newborns. The same was found in laboratory animal experiments where female rats were not affected by exposure to bisphenol as male rats were affected. One possible explanation is that male rats have a smaller amount of enzyme that metabolizes bisphenol.