Mother’s exposure to toxic PFAS chemicals may reduce sperm count

A new peer-reviewed Danish study found that a mother's exposure to toxic PFAS forever chemicals can lead to lower sperm count and quality later in her child's life.

PFAS per and polyfluoroalkyl substances are known to disrupt hormones and fetal development, and future reproductive capacity is defined as testicles develop in utero during the first trimester of a pregnancy, according to co-author Sandra S gaard T ttenborg of Copenhagen University Hospital.

It makes sense that exposure to substances that mimic and interfere with the hormones involved in this delicate process can have consequences for semen quality later in life, S gaard T ttenborg said.

The PFAS are a class of about 12,000 chemicals, which are typically used to make thousands of products resistant to water, stains and heat. They are called forever chemicals because they accumulate in humans and the environment and do not naturally break down. A growing body of evidence links them to serious health problems such as cancer, birth defects, liver disease, kidney disease, and decreased immunity.

The study, published Wednesday in Environmental Health Perspectives, examined semen characteristics and reproductive hormones in 864 young Danish men, born to women who provided blood samples during their pregnancies first trimesters between 1996 and 2002.

The study builds on others that have found similar issues, but it is the first to look for exposure to more than two PFAS compounds and to assess exposure during early pregnancy, which is the male reproductive organ's primary developmental period. Researchers scanned the mothers blood for 15 PFAS compounds and found seven in large enough concentrations to include in the study.

Mothers with higher levels of exposure more often raised adult men with lower sperm counts, as well as elevated immotile sperm levels, meaning their sperm did not swim. This exposure increased the amount of non-progressive sperm that do not swim straight or swim in circles. The ubiquitous chemicals are estimated to be in 98% of Americans' blood, and they can cross the placental barrier and accumulate in the growing fetus. PFAS was detected in all 30,000 samples, according to a study of 40 studies of umbilical cord blood from around the world.

S gaard T ttenborg said that infertility rates are on the rise worldwide, often for unclear reasons.

She added that the results of our studies are an important piece in that puzzle. The more we know, the more we can prevent.