76. Prenatal perfluoroalkyl substances and newborn anogenital distance in a Canadian cohort (lay summary)

Arbuckle TE, MacPherson SH, Foster WG, Sathyanarayana S, Fisher M, Monnier P, Lanphear BP, Muckle G, Fraser WD. Reproductive Toxicology. 2020 Apr 10;94:31-39. doi: 10.1016/j.reprotox.2020.03.011

Perfluoroalkyl substances (PFAS) are persistent chemicals used to resist stains and repel water on items such as furniture, carpets and clothing, and provide non-s​tick capabilities for cookware and other products. Most Canadians have measurable levels of PFAS in their blood.  Some of these chemicals may be endocrine disruptors – chemicals that interfere with hormone systems.  Only a few studies have examined exposure to PFAS during pregnancy and markers of endocrine disruption such as changes in anogenital distance (AGD) in infants.  AGD is the distance between the anus (bottom of the rectum) and penis in infant boys and between the anus and clitoris in infant girls.

In the MIREC study, three PFAS (PFOA, PFOS and PFHxS) were measured in mothers’ first trimester blood samples.  As part of MIREC-ID, anogenital distances were measured in their babies shortly after birth (205 boys and 196 girls).

No consistent associations were observed between PFAS levels in blood of mothers and AGD in their female infants.  In infant boys, increases in mothers’ level of PFOA, but not PFOS or PFHxS, were associated with a small increase in AGD.

Previous research has suggested that shorter AGD in boys may be associated with poorer reproductive health in adulthood.  It is unknown whether the slightly longer AGD in boys associated with PFAS exposure in this study is real or due to chance, or if true, would have any long-lasting effect on their reproductive health.  By following these children as they age, such as in MIREC-ENDO, researchers will be able to examine whether there are any adverse effects of early life exposure to these chemicals on child puberty.