Working with human eggs discarded during in vitro fertilization, scientists from Boston have discovered that bisphenol A affected the egg's ability to mature and disrupted the organization and alignment of chromosomes. It is the first study to investigate effects of BPA on human egg development.
According to Patricia Hunt, the scientist who discovered BPA's effects on maturing mouse eggs, and who was not involved in the new study, these effects could reduce fertility and increase the likelihood of health conditions related to chromosomal damage, including miscarriages and birth defects such as Down Syndrome. The results also may be relevant to growing evidence that fertility is decreasing in both men and women.
Some of the effects are statistically significant at the lowest level tested, which is within the range that the researchers have measured in the fluid in women's follicles. Follicular fluids normally bathe the eggs as they are maturing. "As the BPA dose increased, there was a decrease in the percentage of oocytes that progressed to metaphase II [the second phase of meiosis] and increases in the percentage of oocytes that were degenerated or that had undergone spontaneous activation," the authors wrote.
The authors, who tested 352 eggs from 121 patients, wrote that "additional studies with a larger number of oocytes are required to confirm the present results." They only had access to "clinically discarded oocytes," so they could only evaluate eggs that had failed to mature in the women.
The US Centers for Disease Control has reported that more than 90 percent of Americans have detectable levels of BPA in their urine. Exposure results from the widespread use of the chemical in a variety of products, including some cash-register receipts, cans, and polycarbonate liquid containers. The Food and Drug Association has banned the use of BPA in baby bottles and sippy cups, and also containers for infant formula. In 2012, the French counterpart to the FDA, the French Agency for Food, Environmental and Occupational Health & Safety, banned BPA in all food contact material.
This report was originally published by EnvironmentalHealthNews.org