One of the most challenging aspects of Sarah Bly’s work is helping women cope with infertility.

“It’s not only a mental desire you have around creating a life, but a very deeply physical, primal and biological urge, and these women are dealing with this on all of those levels,” said Bly, a women's health counselor and fertility awareness educator in Oregon.

Bly, who runs a private practice in Ashland, home of Oregon's famous Shakespeare festival, urges women to listen to their bodies in pursuing health and pregnancy. Increasingly, she's asking them to also pay attention to scientists’ alarms over chemical exposure.

“When I first started, I’d say ‘do a cleanse’,” Bly said. “Now I teach classes on how to avoid chemicals in our lives and homes.... Where have you lived? What foods did you eat?”

For women trying fertility treatments, research indicates that exposure to one ubiquitous chemical, bisphenol-A, might greatly impair their chances of having a baby.

But federal agencies remain steadfast in the safety of the chemical, known as "BPA" and found in some canned foods and beverages, paper receipts and dental sealants.

“That position is just untenable,” said Wade Welshons, an associate professor at the University of Missouri who studies estrogen chemicals. “One study after another shows BPA exposure leads to one adverse effect after another.”

FDA stays silent

Multiple studies have found that higher bisphenol-A levels in women undergoing fertility treatment—in vitro fertilization, or IVF—meant a reduction in successful pregnancies.

The most recent study, published last month in the Journal of Clinical Endocrinology and Metabolism, examined 239 women who underwent IVF in Massachusetts from 2007 to 2012. Of the women with the highest exposure to BPA, 17 percent had a baby, compared to 54 percent of women with the lowest exposure.

BPA—used to make plastic hard and shatterproof—mimics the hormone estrogen and acts an endocrine disruptor. Properly functioning hormones are crucial to reproduction, as well as development, brain function and immune systems.

The compound can leach out of can linings and into the food. Studies show that just about everyone has traces of the chemical in their body, and researchers believe diet is the major exposure route.

Welshons said virtually all reproductive impacts from BPA exposure shown in animal studies have been found in humans. The chemical has been shown to impact cell division in the ovaries, and alter menstrual cycles and the uterus.

“We consider it an ovarian toxicant. In addition, strong evidence suggests that BPA is a uterine toxicant,” a group of 11 leading scientists wrote in a 2014 review of the chemical.

Despite this, the U.S. Food and Drug Administration maintains that the amount of BPA leaching from food packaging will not harm people.

The agency declined several opportunities to comment about mounting evidence of BPA and IVF outcomes.

Over the past few years, Environmental Health News has sent multiple requests to speak with FDA scientists about BPA research and been denied every time.

Agency assessments declare that BPA is rapidly cleared from the body, leaving no time for health effects.

“They need to stop pretending that there is no human BPA exposure," Welshons said.

"It’s widely found and in the urine of 90 percent of people,” he added. “We wouldn’t see all of these associations without exposure.”

Soy offers protection, calls previous testing into question

The recent study had a novel finding: soy may protect women from the reproductive impacts of BPA. As levels of the estrogen-mimicking chemical increased, the women who did not eat soy foods had lower birth rates, said senior author Russ Hauser, a professor of reproductive physiology at Harvard University.

It’s not clear why soy, which also interacts with estrogen receptors, appears to mitigate the BPA impacts, Hauser said.

But the results suggest that other studies that do not show a link between BPA and pregnancy might be flawed unless they account for what women eat, Welshons said.

“If there wasn’t control of diet, the study might not find effects that are actually there,” he said.

Hauser’s work builds on previous research suggesting interplay between BPA and fertility treatment success.

A study of 174 women from Boston, Massachusetts, undergoing IVF found that higher BPA concentrations in urine were linked to decreases in cells that eventually mature into eggs. The women with the highest BPA exposure had, on average, 24 percent fewer of the cells than women with the lowest exposure.

A 2011 study of 44 women undergoing IVF found BPA levels linked with reduced estrogen responses during the fertility treatments.

And it may not just be female exposure: researchers report that BPA levels in men’s blood may affect embryo quality during IVF, according to a 2011 study.

The American Chemistry Council, which represents chemical manufacturers, is not convinced. Steve Hentges, a representative from the council, said in an emailed response that “comprehensive multi-generation studies have found that BPA has no effect on reproduction at any dose remotely close to typical human exposure levels.”

When asked specifically about Hauser’s study, Hentges said it is “not adequate to support any medical advice or decisions.”

“Women who are pregnant or trying to become pregnant should consult with their own doctors on questions of nutrition and lifestyle, and certainly should not make critical health decisions based on a single, small-scale study,” he said.

The “most painful loss”

Bly, the fertility counselor, said understanding the possible impacts chemicals such as BPA have on fertility has become “absolutely integral" to her practice. While most women she sees are aware of endocrine-disrupting chemicals, some are not. She encourages natural diets, cleaning products and cosmetics free from endocrine disrupting chemicals, and drinking water out of glass or stainless steel.

But the effort required to avoid these compounds leaves many women intimidated, she said.

“When they look at the science, the studies that show what’s in mother’s breast milk, it’s overwhelming,” Bly said. “It’s a lot to take in … we’re full of this stuff. I try to be careful, encouraging one step at a time. But the struggle with infertility can take a severe toll on women.

“It’s the most painful loss,” Bly said. “Just wanting, waiting, and not happening.”

This article originally ran at Environmental Health News, a news source published by Environmental Health Sciences, a nonprofit media company.