Many women grow up believing they'll be able to get pregnant and have children when they're ready, and see parenthood as an important part of their identity, yet 10 percent of women in the United States have difficulty conceiving or staying pregnant. A recent study suggests a common household chemical could be one of the many risk factors that affect a woman's fertility.

Researchers at Harvard T.H. Chan School of Public Health found a type of flame retardant known as PFRs, which are used in polyurethane foam in furniture, carpet and gym mats, can decrease a woman's chances of fertilization, pregnancy and live birth for those undergoing in-vitro fertilization treatment.

In the study, published in Environmental Health Perspectives, 80 percent of women had traces of three PFRs in their urine. Women with the highest levels of byproducts experienced the following: a 10 percent decrease in fertilization rate; a 31 percent lower rate of embryo implantation; 41 percent lower rate of a clinical pregnancy (fetal heartbeat confirmed by ultrasound); and a 38 percent lower rate of a live birth.

Originally, PFRs were introduced as a safer alternative to the flame retardant PentaBDE, which was used in polyurethane foam, but was phased out more than a decade ago after it was linked to health problems in both animal and epidemiological studies, where researchers are looking to see how frequently certain problems appear in different groups of people, and why. But evidence that PFRs are endocrine disruptors, which interfere with the body's hormones, is mounting. These substances are also hard to avoid; they can easily transfer from dust into the body, where they can be found in high concentrations in urine, blood, and even breast milk.

Courtney Carignan, study co-author and a research fellow in the Department of Environmental Health at Harvard, believes the findings show PFRs could be another risk factor for lower reproductive success among women undergoing IVF. Previous research has also linked pesticides and phthalates - hormone-disrupting chemicals - to infertility and lower chances of getting pregnant. Limiting exposure to these chemicals, in addition to PFRs, could boost a woman's fertility.

The study "also adds to the body of evidence indicating a need to reduce the use of these flame retardants and identify safer alternatives," said Carignan in a statement.

How do you limit your exposure to a chemical that's in the air? Carignan suggests looking for furniture with barrier technology or a naturally flame retardant fabric, such as leather or wool, that meets flammability standards. When it comes to mattresses, they don't come with flame retardants, but polyurethane foam mattress pads can. Other alternatives include carpet-free floors or carpet with padding not made from foam.

But don't worry if you have items in your home that might contain these chemicals. In an interview with The Huffington Post, Carignan said it's OK if finding alternatives isn't possible: “This is just one factor, and people need to be careful not to beat themselves up over these types of exposures," she said. Simple solutions, like good-hand washing practices before meals, can help lower levels of these chemicals in the body.

Carignan and her colleagues focused on a small subset of 211 women undergoing IVF at the Massachusetts General Hospital Fertility Centre between 2005 and 2015. This group signed up to be a part of the the Environment and Reproductive Health (EARTH) study. The women provided one to two urine samples for each IVF cycle for researchers to analyze for any chemical byproducts.

Women doing IVF treatments were selected because the researchers believed it was the most efficient way to observe every step of conception and early pregnancy. Women who conceive naturally may not be aware they're pregnant until they are six to eight weeks along.

This is the first study of its kind to link PFRs and pregnancy outcomes, the statement noted. Further research is needed to assess how these chemicals also affect men, and the effects that different types of chemicals may have on both sexes.

Until then, hopeful mothers should not stress about removing carpet or buying new furniture just yet.

Source: Carignan CC, Minguez-Alarcon L, Butt CM et al. Urinary Concentrations of Organophosphate Flame Retardant Metabolites and Pregnancy Outcomes among Women Undergoing in Vitro Fertilization. Environ Health Perspect. 2017.