New York: Pregnant women with higher blood levels of a common plastic chemical used in the coatings of food containers are more likely to deliver their babies early compared with women with lower levels of that chemical, says a study led by an Indian-origin researcher. The researchers investigated the role of Bisphenol A, or BPA, blood levels on risk of preterm birth. "Women are continuously exposed to BPA because it's used in the construction and coatings of food containers and its release into food is increased by microwave or other heat sources," said Ramkumar Menon, assistant professor at The University of Texas Medical Branch (UTMB) at Galveston, US. "In fact, BPA is so widely used that nearly all women have some level of exposure," Menon pointed out. Conducting in collaboration with Winthrop University Hospital and Kaiser Permanente Southern California, the UTMB investigators analysed blood samples from pregnant women when they were admitted to the hospital for labour and delivery and from the amniotic fluid of the fetus collected during labour. Increased BPA concentration is associated with an increased risk for preterm birth, the findings showed. The study was published in The Journal of Maternal-Fetal and Neonatal Medicine. "Widespread use of BPA in materials of our daily life and our findings that all patients have some level of exposure suggests that contact with these materials is unavoidable," Menon said. "This suggests that a better understanding of how BPA may alter maternal physiology is needed to minimise the risk of adverse pregnancy outcomes," he pointed out.