In a big U.S. study, boys and girls seemed equally affected by mom's exposure to PFAS chemicals during pregnancy when it comes to behavior problems — there's no clear difference between them.

What we've found so far is that prenatal exposure to PFAS chemicals appears to affect behavior in U.S. children between the ages of 1.9 and 15 years, but there is no clear difference in how boys and girls are impacted [1]. Our analysis of the available research suggests that both boys and girls show similar links between maternal PFAS exposure during pregnancy and later behavioral issues. We looked at one key assertion from a large U.S. study, which reported that the effects of prenatal PFAS exposure on child behavior do not strongly favor one sex over the other [1]. In other words, the evidence we’ve reviewed so far does not point to a meaningful sex-specific pattern — boys and girls seem to be affected in comparable ways. This finding is based on data from a broad sample, but we are relying on a single assertion for this conclusion. It’s important to note that while the current evidence leans toward no major difference between sexes, our analysis is limited by the small number of assertions we’ve reviewed — just one so far. We cannot rule out subtle differences that future studies might detect. Also, “behavior problems” can cover a wide range of outcomes, and the evidence does not specify which types of behaviors are most affected. Our current analysis shows that sex may not be a key factor in how prenatal PFAS exposure influences child behavior, at least based on what we’ve seen so far. But because the body of evidence is still narrow, we expect our understanding to evolve as more data becomes available. Practical takeaway: For now, it looks like boys and girls may face similar behavioral risks from PFAS exposure before birth — so steps to reduce exposure during pregnancy could be equally important for all families.