PFAS in pregnancy: what forever chemicals can mean for mothers and babies

PFAS — per- and polyfluoroalkyl substances, the so-called forever chemicals — are synthetic compounds that barely break down in the environment and leave the human body only very slowly. They build up over years. That is why two groups matter more than anyone else: women who are pregnant or hoping to be, and the babies and young children they carry and feed.

What follows is what the large health bodies say the evidence shows — the US Environmental Protection Agency (EPA), the Agency for Toxic Substances and Disease Registry (ATSDR, part of the CDC) and the National Academies of Sciences, Engineering, and Medicine — together with some of the larger recent studies. We have tried to say how strong each finding is. “Linked to” is not the same as “causes”, and a worried parent deserves to know the difference.

What the evidence says for mothers

Pregnancy changes the body quickly — hormones, metabolism, blood pressure — and it is a window in which chemical exposure can matter more than usual.

• High blood pressure and pre-eclampsia. EPA lists increased blood pressure in pregnant women among the possible effects of PFAS, and ATSDR names pregnancy-induced hypertension and pre-eclampsia for PFOA and PFOS. The National Academies rate the evidence as limited or suggestive: a real signal, not yet a settled one.
• Gestational diabetes. Many studies link higher PFAS levels, PFOA in particular, to higher blood sugar in pregnancy and to gestational diabetes, though not all of them do. A 2025 review that pooled 28 studies found the association held overall.
• Fertility. EPA lists decreased fertility. In a 2023 study of 1,032 women trying to conceive in Singapore, led by researchers at Mount Sinai, women with higher PFAS levels took longer to become pregnant and were less likely to — by as much as 40 per cent, the researchers estimated.
• The mother’s own health, years later. In Project Viva, a long-running study in Massachusetts, women with higher PFOS in early pregnancy weighed more and carried more body fat almost 18 years later. Weight gained in midlife matters, because it raises the risk of diabetes and heart disease.

What the evidence says for babies and children

PFAS cross the placenta, so a baby is exposed before birth, and they pass into breast milk afterwards. That does not make breastfeeding the problem — see the box below — but it explains why the effects can show up so early.

• Lower birth weight. This is one of the best-established findings. The National Academies rate the evidence that PFAS reduce a baby’s growth before birth as sufficient, their strongest category; on average the effect on birth weight is small.
• A weaker response to vaccines. Also rated sufficient by the National Academies: children with higher PFAS levels make fewer antibodies after routine vaccinations. EPA describes it as a reduced ability of the immune system to fight infections.
• Blood pressure in childhood and the teenage years. In the Boston Birth Cohort — 1,094 children followed for a median of twelve years — higher PFAS in the mother’s blood around delivery was linked to higher blood pressure later in childhood, most clearly in adolescence.
• Weight and obesity. Among Project Viva’s children, higher PFAS in pregnancy was linked to a 13 to 59 per cent higher risk of obesity at 16 to 20, depending on the compound, with body mass index climbing faster from around the age of nine.
• Development and hormones. EPA’s list also includes developmental effects in children — accelerated puberty, bone variations, behavioural changes — and interference with the body’s natural hormones.

What you can do

Nobody can bring their exposure to zero: PFAS reach us through food, dust and everyday products as well as water. Drinking water is the part a household can do most about, and it matters most for a baby fed on formula.

• Find out what is in your water. In the United States, ask your water utility for its PFAS results or look in its annual water quality report; a private well needs its own test. In the European Union, every member state has had to monitor PFAS against a binding limit since January 2026 — more on that here.
• If PFAS are there, treat the water at the tap. Reverse osmosis, or a filter certified for PFAS reduction under NSF/ANSI 53 or 58, lowers them. Check that the certification names PFAS, and replace cartridges on schedule. Boiling does not remove PFAS.
• Keep breastfeeding, and make formula with safe water.
• Tell your doctor if your exposure may have been high — near an airfield, a factory or a supply known to be contaminated. The National Academies advise doctors to offer PFAS blood testing to people likely to have had high exposure.

Why this matters to us

The Foundation funds water systems for children’s homes and shelters in Greece, and in New York and New Jersey we are building partnerships with organisations that house pregnant women, young mothers and their babies. The people living there drink whatever water the building has.

That is why we ask for proof rather than promises. The Twin system fitted by our partner NearonYdor in the homes we fund in Greece was tested by the Chemistry Department of the National and Kapodistrian University of Athens for fifteen PFAS compounds, including the short-chain ones that are hardest to remove. After filtration every one of them was below the limit of detection.

If you would like to help us bring the same water to more mothers and children, the ways to give are on our donate page.

Sources

1. US Environmental Protection Agency, Our current understanding of the human health and environmental risks of PFAS (updated July 2026).
2. Agency for Toxic Substances and Disease Registry, How PFAS impacts your health (2025) and Breastfeeding and PFAS (2024).
3. National Academies of Sciences, Engineering, and Medicine, Guidance on PFAS exposure, testing, and clinical follow-up (2022).
4. Centers for Disease Control and Prevention, Breastfeeding and environmental exposures.
5. Systematic review and meta-analysis of 28 studies, prenatal PFAS exposure, glucose homeostasis and gestational diabetes, Journal of Hazardous Materials (2025).
6. Mount Sinai, PFAS exposure linked to significantly reduced fertility, S-PRESTO cohort, Science of the Total Environment (2023).
7. Project Viva, Early pregnancy plasma PFAS and maternal midlife adiposity, Journal of Clinical Endocrinology & Metabolism (2025).
8. Boston Birth Cohort, Prenatal PFAS exposures and blood pressure in children aged 3 to 18, Journal of the American Heart Association (2025).
9. Project Viva, prenatal PFAS and obesity in adolescence, Environmental Health Perspectives (2023).
10. US Environmental Protection Agency, Reducing PFAS in your drinking water with a home filter.
11. Laboratory report, Chemistry Department, National and Kapodistrian University of Athens (fifteen PFAS compounds, LC-MS/MS).