A recent study has reportedly claimed that bisphenol A (BPA) can disrupt the maturation of human oocytes in vitro, raising questions about the effect of the substance on human development and fertility. Ronit Machtinger, et al., “Bisphenol-A and human oocyte maturation in vitro,” Human Reproduction, August 2013. Researchers apparently analyzed the impact of both high (20 μg/ml) and lower concentrations (20 ng/ml and 200 ng/ml) of BPA on clinically-discarded oocytes obtained from patients undergoing fertility treatments at Brigham and Women’s Hospital. According to a July 31, 2013, hospital press release, the results evidently showed that as BPA dose increased, there was (i) “a decrease in the percentage of eggs that matured,” (ii) “an increase in the percentage of eggs that degenerated,” and (iii) “an increase in the percentage of eggs that underwent spontaneous activation, the abnormal process when an egg acts as though it has been fertilized, even though it has not been.”

“To our knowledge, this is the first study investigating the effect of BPA on oocyte meiotic maturation, spindle morphology and chromosome alignment in human oocytes,” wrote the study’s authors. “Together with prior animal studies, the data support the negative influences of BPA on cell cycle progression, spindle architecture and chromosome organization during oocyte maturation. Furthermore, the increased rates of abnormal maturation in oocytes exposed to BPA may be relevant to our understanding of the decrease in fertility reported in the last decades.”