Pesticides Could Seriously Affect Women's Pregnancies, New Study Finds

For women struggling with infertility, sometimes in vitro fertilization offers them the best chance at getting pregnant. If you ask any woman whose undergone IVF — myself included — they'll tell you all the myriad of complementary lifestyle changes they've made at the same time to optimize their chances for a successful IVF cycle: everything from tossing back wheat grass shots, to eliminating dairy, gluten, sugar, or unprocessed foods from their diets. According to a new study published in JAMA Internal Medicine, women undergoing IVF have something else to consider, too: Women who consumed high-pesticide produce were less likely to get pregnant via IVF.

The study tracked 325 women undergoing infertility treatments to get pregnant and several factors that could influence their IVF cycles, such as weight, age, and diet. Using detailed diet questionnaires, researchers matched the foods these women ate against the U.S. Department of Agriculture pesticide database, a comprehensive list of foods with pesticide residue. Foods with some of the the highest amounts of pesticide residue include strawberries, spinach, and tomatoes. What the researchers found was startling: Women who were exposed to the highest amounts of pesticide via high-pesticide produce were 18 percent less likely to get pregnant during their IVF cycles. Even more jarring: These women were also 26 percent less likely to have a live birth, meaning they were more likely to suffer miscarriages.

The researchers were quick to point out that 90 percent of the population in the United States has "detectable concentrations of pesticides or their metabolites" in their urine and blood — ew. That said, their data seems to provide a link between pesticides and IVF failure rates — more specifically, that higher amounts of pesticides consumed post-infertility treatment can result in increased IVF cycle failures or miscarriage.

The researchers also noted that theirs was the first study to specifically evaluate the relationship between pesticide consumption via diet and human "reproductive success" — which is why they tracked women undergoing infertility treatments: IVF is a far more carefully controlled human reproduction scenario than couples trying to have a baby the old-fashioned way. Between cycle timing and the amount of diagnostics and monitoring that occurs in a normal IVF cycle, there are a lot more variables about "reproductive success" that researchers are able to observe and record.

One of the biggest limitations of the study is that the researchers only examined self-reported pesticide exposure. The study participants' blood and urine were not tested, and researches relied solely on the comparative data between what participants reported they ate with a U.S. government database of known high-pesticide foods.

Associate professor of nutrition and epidemiology at Harvard T. H. Chan School of Public Health, Dr. Jorge Chavarro, was the senior investigator for the study. The researchers noted that, because this was the first study of its kind, their findings must be confirmed — like all good scientific studies. This is a particularly salient point, as the study doesn't specifically prove that pesticides can cause infertility; however, it's the first study of its kind to point researchers in the direction of where and how to investigate the relationship between fertility and pesticides further. Chavarro told TIME:

I was always skeptical that pesticide residues in foods would have any impact on health whatsoever. So when we started doing this work a couple of years ago, I thought we were not going to find anything. I was surprised to see anything as far as health outcomes are concerned.

So what does this mean for women who need or plan to undergo IVF? You might want to give any fruits and veggies in your fridge an extra scrub, and perhaps, on the next trip to Whole Foods, head right to the organic produce section.