Higher exposure to “forever chemicals” found in the environment and many everyday products may help explain why some women struggle to get pregnant, new research suggests.
The study found that higher levels of perfluoroalkyl substances – known as PFAS – in the blood of would-be mothers were associated with up to 40 per cent lower chances of achieving a successful pregnancy.
The researchers at the Icahn School of Medicine at Mount Sinai in New York, the US, say women trying to conceive should therefore avoid products known to contain PFAS, such as non-stick cookware, microwaveable popcorn or anti-stain fabrics.
“PFAS does reduce fertility in women, and PFAS exposure should be reduced in women who are planning a pregnancy in order to make it easier for them to conceive,” the study’s lead author Dr Nathan Cohen told Euronews Next.
He and his colleagues looked at blood samples from 382 women aged 18-45 who were trying to get pregnant and were enrolled in a preconception study in Singapore.
The samples were collected from the women between 2015 and 2017, and the women were followed up for at least one year.
The researchers found that higher exposure to a handful of specific and common PFAS was associated with a lower probability of pregnancy and live birth – not only when looking at each PFAS individually, but even more so when combined.
For women who did get pregnant, the higher the exposure to a mixture of PFAS, the longer it took to get a positive pregnancy test.
What are PFAS?
PFAS are a class of manmade chemicals that have been used for decades across a wide range of industries to make products resistant to heat, water, grease and stains.
They have also recently been found in more unexpected places, such as toilet paper and period underwear.
Because of their very strong fluorine-carbon bonds, these chemicals don’t break down easily in the environment and in our bodies. Instead, they accumulate for months or years, and traces of them have been found in virtually every place on Earth, including in polar bears in the Arctic.
Previous research has linked PFAS to a weaker response to vaccination and an increased risk of certain types of cancer, particularly kidney and testicular cancer.
The team at Mount Sinai noted that while other studies have demonstrated that PFAS impair reproductive functioning in female mice, theirs is one of the first to show its impact in humans.
Disrupting reproductive hormones
The researchers suspect the way PFAS affects female fertility is by wreaking havoc on reproductive hormones.
“But we didn’t have data available on female reproductive hormone levels, so we can’t we couldn’t really confirm that with the data that we had,” Cohen said.
Another limitation of the study was that it only looked at seven of the most prevalent PFAS – out of the thousands that existed – and that it did not have any data on would-be fathers’ exposure to these chemicals.
Recent research has found that women’s exposure to PFAS during early pregnancy could result in their children having a lower sperm count and quality later on.
“PFAS can disrupt our reproductive hormones and have been linked with delayed puberty onset and increased risks for endometriosis and polycystic ovary syndrome in several previous studies,” senior author Dr Damaskini Valvi, Assistant Professor of Environmental Medicine and Public Health at Icahn Mount Sinai, said in a statement.
“What our study adds is that PFAS may also decrease fertility in women who are generally healthy and are naturally trying to conceive.”
The biggest contributor to the PFAS mixture associations was perfluorodecanoic acid (PFDA) – a breakdown product of stain- and grease-proof coatings on food packaging, couches, and carpets – which was individually linked to reduced fertility.
Associations with infertility were also observed for exposure to perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluoroheptanoic acid (PFHpA).
The researchers, whose findings were published in Science of the Total Environmentare now calling for stricter regulations banning the use of toxic chemicals, such as PFAS, from everyday products.
Last year, the US Environmental Protection Agency (EPA) found that PFAS could cause harm at levels “much lower than previously understood” and that almost no level of exposure was safe.
PFAS are not the only chemicals seeping into our water and food products to be suspected of impaired fertility. Research has also linked phthalates and bisphenolswhich are found in many packagings, to lower sperm counts.