TMC PULSE

t m c » p u l s e | m a y 2 0 1 6 34 A team of researchers at The University of Texas Medical Branch at Galveston (UTMB) recently discovered a link between Bisphenol A, more commonly known as BPA, and preterm birth. The results of the three- year study, which was published in the Journal of Maternal-Fetal and Neonatal Medicine this past March, indicated that women with higher levels of BPA in their blood were more likely to give birth prematurely than those with lower levels. According to the Centers for Disease Control and Prevention, preterm birth rates have steadily declined over the past decade, but it still affects approximately one in 10 babies in the United States. Because babies undergo critical growth in the final weeks of pregnancy, preterm birth increases the potential risk of under- developed organs (such as the brain, lungs and liver), cerebral palsy, develop- mental delays and vision impairments. Led by reproductive and perinatal biologist Ramkumar Menon, Ph.D., assistant professor of obstetrics and gynecology at UTMB, the team analyzed BPA concentration levels in maternal plasma and amniotic fluids in selected samples from a biobank of more than 3,500 pregnant women. "My lab is looking at causality and pathways of preterm birth and mater- nal health from a fetal perspective, meaning, 'What is the response of the fetus if the mother is getting exposed to environmental toxicants like BPA?'" Menon said. "We wanted to know why estrogen in their chemical nature. The system is getting fooled by these xenoestrogens and [causing] inflamma- tion—the same type of response as you would expect from estrogen at term but from the xenoestrogen prematurely." The industrial chemical compound has been widely used since the 1960s in common household products, such as water bottles, epoxy-lined canned foods and water piping. In addition, BPA can be found in less conspicuous appli- cations, including the dental sealants used in teeth fillings, sports equipment and even cash register receipts. Although decades of research have shown BPA to be a known endocrine disruptor chemical that interferes with estrogenic signaling and a contributing it has distinct effects on the mother and the baby's tissues during the pregnancy period. Those are the investigations that are ongoing because sometimes we can prevent some of these issues by knowing if it goes here, certain things will happen." Based on the chemical nature of BPA, the compound can be easily metabolized through the liver or detox- ified in the placenta, made inactive and secreted from our bodies, but consistent exposure to BPA can lead it to accumulate either in its active or inactive form. "The liver modifies the chemi- cal and makes it an inactive or inert compound, but it can still be detected in your assay, blood or amniotic fluid," Menon said. "If the exposure level is high, detectable levels of BPA are get- ting accumulated in the amniotic fluid and maternal blood and those high lev- els of BPA are linked to preterm birth." The prevalent use of BPA has caused the scientific community to closely examine its effects on the human body, particularly in pregnant women and children. Because BPA and estrogen share structural similarities, BPA is able to bind to estrogen recep- tors and chemically mimic the female hormone when introduced in the mater- nal blood or amniotic fluid. "If you look at the normal parturi- tion in humans, estrogen increase is associated with normal labor and deliv- ery," Menon said. "What happens when the mother is exposed to BPA, or what we call xenoestrogen, is that they mimic factor in brain and reproductive devel- opment problems, BPA is still one of the highest volume chemicals produced worldwide, with approximately six billion pounds produced each year, according to the CDC. The heightened safety concerns surrounding BPA in consumer goods have led many food and beverage companies to rethink their approach to packaging. In 2012, the Food and Drug Administration officially banned the use of the chemical in baby products in response to growing public concern and a petition filed by the chemical industry's main trade association, the American Chemistry Council. A num- ber of manufacturers have followed suit, but even though many plastic bottles and food containers now tout "BPA- free" labels, Menon's colleague on the study, Cheryl Watson, Ph.D., professor of biochemistry and molecular biology at UTMB, said those descriptions create a false sense of security and safety. "BPA is an incredibly common plas- tic, and people like it because it's clear More Bad News for BPA UTMB Galveston scientists have discovered a link between BPA and increased risk of preterm births B y S h a n l e y C h i e n BECAUSE BPA AND ESTROGEN SHARE STRUCTURAL SIMILARITIES, BPA IS ABLE TO BIND TO ESTROGEN RECEPTORS AND CHEMICALLY MIMIC THE FEMALE HORMONE WHEN INTRODUCED IN THE MATERNAL BLOOD OR AMNIOTIC FLUID.

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