Both males and females should consider trying to lower their exposure to endocrine disrupting chemicals (hormone disrupting chemicals) when contemplating pregnancy. These chemicals are found in many personal care, food packaging, and plastic products. They can interfere with natural hormone function and are linked to a wide assortment of health problems. Evidence (like this study) is mounting that higher levels of endocrine disruptors in the body have a negative effect on the developing embryo. So men - an important time to try to lower your exposure to endocrine disruptors is the 3 months preconception (it takes about 3 months for sperm to mature), and for women it's the entire pregnancy period (from conception to birth). You can't totally avoid endocrine disrupting chemicals (they're detected in almost all of us), but you can lower your exposure.
What to avoid and what to do? Read the ingredient lists of all personal care products and try to avoid those with phthalates, parabens, triclosan, bisphenol-A (BPA), BPS, triclocarbon, and oxybenzone (BP-3). Try to buy "unscented" or "fragrance-free" products. Canned foods are considered one of the most significant routes of human exposure to bisphenol A (BPA), so limit canned foods. Note that "BPA-free" cans and plastic containers also contain endocrine disruptors. Another way to lower exposure to endocrine disruptors is to buy and store food not in plastic containers, but in glass containers or stainless steel. Don't microwave food in any sort of plastic containers. Avoid products with fragrances in them, including air fresheners and dryer sheets. Avoid flexible vinyl (e.g. shower curtains). [For all posts on endocrine disruptors, and an article from National Institutes of Health. Also check ewg.org for lists of products]. From Environmental Health News:
Are plastic chemicals in dads hurting embryos?
Turns out, moms, it's not just about you staying off alcohol and avoiding potentially harmful chemicals while pregnant or trying to become so. Your partners' exposure to plastics and packaging could play an important role in your ability to conceive a child. A father’s exposure to chemicals commonly found in plastics, personal care products and food packaging might decrease the quality of embryos produced by their sperm, according to a new study out of Massachusetts.
The study, published today in the journal Human Reproduction, is the first to examine dads’ exposure to phthalates and embryo quality through five days of in vitro fertilization (IVF). The lower quality embryos had fewer signs of the type of progress that leads to a fetus. The findings suggest men’s exposure to the chemicals—used in vinyl products, food packaging, fragrances and in other plastics to make them pliable—might hamper the development of their unborn. Embryos are the result of a fertilized egg in a woman and are the precursor to the fetus. About 12 weeks into pregnancies, the unborn is considered a fetus.
Most people have phthalates in their bodies and the compounds disrupt the endocrine system—interfering with hormones that are crucial for reproduction.While the study doesn’t prove phthalates in men lead to poor quality embryos, it adds to mounting evidence that the ubiquitous chemicals may impact pregnancies. “Sperm mature over 72 days on average, almost three months,” said senior author of the study, Richard Pilsner, an epidemiologist and assistant professor at the University of Massachusetts Amherst. “During that time, we may tell men to maybe try to avoid phthalates. There’s no way to totally escape exposure but you could minimize it.”
Led by Pilsner, researchers collected 761 immature eggs from 50 couples undergoing IVF at the Baystate Medical Center in Springfield, Mass., and checked their progression to embryos. They tested embryos at three days and five days after the eggs were fertilized, and collected urine samples from the couples on the same day as the semen sample and egg retrieval to test for phthalate metabolites, substances formed after the body processes phthalates. At day five, high exposure to phthalates in men was linked to fewer—or no—signs of the type of development that eventually leads to a fetus and placenta compared to men with lower exposure.
Phthalate exposure for fetuses has been linked to genital defects, lower IQs and miscarriages but it’s not clear what impacts this poor embryo quality could mean for the unborn. Russ Hauser, a professor of reproductive physiology at Harvard University, said in an email that the impacts might range from pregnancy loss to effects on children's health later in their life.
Shanna Swan, a professor of reproductive science at Mount Sinai Hospital in New York who was not involved in the study, said the study is limited in that it is small, and not representative of the general population because it only included couples undergoing IVF. They also didn’t see any association with the women’s exposure and decreased embryo quality. But this isn’t the first study to report a male-only effect. Higher phthalates in father’s urine was associated with an increased time for couples to conceive, according to a 2014 study. Swan said the current study was strengthened in that it is “remarkably consistent” with the 2014 study. Some phthalate metabolites linked to impacts in both studies are known to target male reproductive hormones, she said.