A growing body of evidence suggests that women who have high urine levels of bisphenol-A—a chemical used in some hard plastics and to coat metal cans—are more likely to suffer from infertility, and now researchers have found a possible reason why. BPA may disrupt eggs from maturing properly, according to a study from Brigham and Women’s Hospital researchers.
“As many as 20 percent of infertile couples have unexplained infertility, and this might just shed a glimmer of light on a contributing factor that plays a role,” said study co-author Catherine Racowsky, director of the hospital’s assisted reproductive technologies laboratory.
In the study published Wednesday in the journal Human Reproduction, she and her colleagues exposed more than 350 immature eggs, which were left over from infertility procedures, to varying amounts of BPA in lab dishes. Only 35 percent of eggs exposed to the lowest levels of BPA had a normal number and configuration of chromosomes after they fully matured compared with 71 percent of those in a control group of eggs that weren’t exposed to BPA.
Most of the eggs exposed to the highest levels of BPA failed to mature at all, and the rest had abnormal chromosomes.
Women trying to get pregnant shouldn’t panic, however, since the lowest BPA levels used in the study were still far higher than levels measured in most women in previous research studies examining BPA and infertility. And lab findings don’t necessarily reflect what happens to eggs in the ovary.
There’s also not much women can do for the time being to reduce their exposure to BPA. “It’s everywhere in our environment,” Racowsky said. “And it likely doesn’t act independently” but acts with other chemicals that also disrupt reproductive hormones. “We really need a better understanding of all this,” she added, “and that will take more research funding.”