PFAS (per- and polyfluoroalkyl substances) are among the most extensively studied environmental chemicals in reproductive medicine. The evidence base connecting PFAS exposure to impaired fertility in both men and women has grown substantially over the past decade. This article reviews what the research actually shows, separating robust findings from preliminary associations, and explains what steps couples trying to conceive can take to reduce their PFAS load.
PFAS and female fertility
Multiple prospective studies have found associations between higher serum PFAS concentrations and reduced fecundability (the probability of conceiving in any given menstrual cycle). A 2009 study in Human Reproduction, analysing data from the Danish National Birth Cohort, found that women with higher PFAS levels had significantly longer time to pregnancy. A 2012 American Journal of Epidemiology study of Danish women found that women in the highest quartile of PFOS and PFOA levels were 70 to 134% more likely to have subfertility requiring more than 12 months to conceive.
The biological mechanisms include disruption of oestrogen and progesterone signalling, interference with thyroid function (which is essential for ovulation and early pregnancy), and direct effects on ovarian reserve. PFAS have been detected in follicular fluid surrounding developing eggs, suggesting direct ovarian exposure. PFAS also interfere with luteinising hormone, the pituitary signal that triggers ovulation.
PFAS and male fertility
The evidence for male reproductive harm is also substantial. A 2009 study in Human Reproduction found that men with higher PFOS and PFOA exposure had significantly lower sperm concentration, lower total sperm count, and reduced sperm motility. A 2012 study in Environmental Health Perspectives found reduced sperm quality at PFAS concentrations within the range found in the general US population. PFAS disrupt androgen signalling by binding to androgen receptors and reducing testosterone production in Leydig cells, the testicular cells responsible for testosterone synthesis.
IVF and PFAS
For couples undergoing IVF, PFAS exposure is associated with lower fertilisation rates, reduced embryo quality and lower live birth rates per transfer. A 2019 study in Environment International found that women undergoing IVF with higher PFAS levels had lower odds of clinical pregnancy and live birth. Critically, the researchers found dose-dependent effects at concentrations that overlap with concentrations found in the general population, not just in highly exposed occupational groups. This is significant because it implies that reducing PFAS exposure in the general fertility population, not just in highly exposed individuals, could improve IVF outcomes at a population level.
Reducing exposure
The highest dietary sources of PFAS are non-stick cookware, microwave popcorn, fast food packaging, and contaminated drinking water. Switching non-stick cookware to cast iron, carbon steel or stainless steel, installing a reverse osmosis filter on the drinking water supply, and avoiding PFAS-coated packaging addresses the primary exposure routes. PFAS body burden falls after stopping exposure, though slowly: PFOA has a serum half-life of approximately 3.8 years. Beginning to reduce exposure well before a planned pregnancy is therefore more valuable than starting at conception.