PFAS Exposure During Pregnancy: What Expecting Parents Need to Know

Why Pregnancy Is a Critical Window

Of all the periods in life when PFAS exposure matters most, pregnancy and early infancy stand out. The developing fetus is exquisitely sensitive to chemical exposures — systems that take years to fully mature can be disrupted by relatively small amounts of PFAS. And unlike adults, the fetus has no choice in the matter: PFAS from the mother’s bloodstream cross the placental barrier and accumulate in fetal tissue.

This article summarizes what the science says about PFAS exposure during pregnancy, what it means for you and your baby, and the concrete steps you can take right now to reduce risk.

PFAS Cross the Placental Barrier

Multiple studies have confirmed that PFAS transfer from maternal blood to fetal circulation during pregnancy. A 2020 study published in Environmental Health Perspectives measured PFAS in umbilical cord blood and found detectable levels of PFOA, PFOS, and other compounds in essentially all samples — meaning PFAS exposure begins before birth for most babies in the United States today.

PFAS also accumulate in breast milk. Breastfed infants can receive additional PFAS exposure through nursing. The critical balance to understand: the known, well-documented benefits of breastfeeding substantially outweigh the risks from PFAS in breast milk for most women. The recommendation from the American Academy of Pediatrics and major health organizations remains to breastfeed where possible — but to reduce the underlying PFAS exposure through water filtration.

What the Research Shows: Pregnancy Risks

A large and growing body of research has associated maternal PFAS exposure with a range of adverse pregnancy and birth outcomes.

Preeclampsia

Preeclampsia — dangerous pregnancy-induced hypertension — has been linked to PFAS exposure in several studies. A 2019 meta-analysis of nine studies found that women with higher PFOA blood levels had increased odds of developing preeclampsia. The biological mechanism likely involves PFAS-induced disruption of endothelial function (the inner lining of blood vessels).

Gestational Diabetes

Multiple studies have found associations between PFAS exposure and gestational diabetes. PFAS appear to interfere with insulin signaling and glucose metabolism — pathways that are already under stress during pregnancy.

Preterm Birth

Higher maternal PFAS concentrations have been associated with increased risk of preterm birth (birth before 37 weeks) in several cohort studies. Preterm birth is a leading cause of infant mortality and long-term health complications.

Birth Weight and Growth

One of the most consistently replicated findings in PFAS research is that higher maternal PFAS levels are associated with lower infant birth weight. Low birth weight is a risk factor for respiratory problems, immune deficiency, and long-term cardiovascular and metabolic disease.

Thyroid Function During Pregnancy

Thyroid hormones are critical during pregnancy for fetal brain development. PFAS disrupt thyroid hormone production and transport. Even modest thyroid disruption during the first trimester — when the fetus relies entirely on maternal thyroid hormones — can have lasting neurological consequences.

Risk to the Developing Baby

Beyond the pregnancy itself, PFAS exposure in utero and during early infancy carries long-term risks for the child:

• Immune system development — PFAS impair the developing immune system. Studies show that children with higher in-utero PFAS exposure produce fewer antibodies in response to childhood vaccines.
• Neurodevelopment — Some research has linked prenatal PFAS exposure to changes in cognitive development, attention, and behavior, though this area is still being studied.
• Metabolic programming — Early PFAS exposure may affect how the body regulates fat storage, cholesterol, and blood sugar in ways that persist throughout life.
• Endocrine disruption — Prenatal PFAS exposure can alter sex hormone levels, potentially affecting pubertal timing and reproductive function decades later.

What Level of PFAS Is Considered Risky During Pregnancy?

The 2022 National Academies of Sciences, Engineering, and Medicine (NASEM) report on PFAS health effects specifically addressed vulnerable populations including pregnant women. The report noted that the current evidence suggests pregnant women and their fetuses may be affected at lower PFAS blood concentrations than the general adult population.

The NASEM report’s clinical guidance for anyone with measured PFAS blood levels above 2 ng/mL is to consult with a physician — and this threshold is especially relevant for pregnant women and those planning pregnancy. If you have reason to believe you have elevated PFAS exposure (you live near a military base, industrial site, or your water has tested above MCL limits), asking your OB or midwife about PFAS blood testing is a reasonable step.

Reducing PFAS Exposure During Pregnancy

You cannot eliminate PFAS exposure entirely, but you can meaningfully reduce it — particularly from drinking water, which is the primary controllable exposure route.

1. Filter Your Drinking and Cooking Water

This is the single most impactful step. Reverse osmosis filtration removes 99%+ of all PFAS compounds and is the recommended choice during pregnancy. If RO is not feasible, a pitcher or under-sink filter certified to NSF P473 (specifically for PFOA and PFOS) is a meaningful step.

If you have not yet checked whether your tap water contains PFAS, look up your ZIP code on CheckPFAS to see EPA test results for your area. Even if your results are below the MCL, a filter provides an additional margin of safety during pregnancy.

See our filter reviews for specific product recommendations at every budget, including countertop options that require no installation.

2. Avoid PFAS in Non-Water Sources

PFAS in water are the most significant controllable exposure, but dietary and contact exposures also contribute:

• Nonstick cookware — Switch to cast iron, stainless steel, or ceramic-coated cookware. Avoid Teflon (PTFE-coated) pans, especially at high heat.
• Food packaging — Microwave popcorn bags, fast food containers, and some paper products are treated with PFAS. Cook from scratch when possible during pregnancy.
• Stain-resistant products — Scotchgard-treated furniture, PFAS-treated carpeting, and waterproof clothing can off-gas PFAS. Prioritize natural fibers and untreated fabrics.
• Canned goods — Some can liners contain PFAS; reduce reliance on canned foods when fresh or frozen alternatives are available.

3. Use Ready-to-Feed Formula if Not Breastfeeding

If you are formula-feeding, ready-to-feed liquid formula is manufactured without tap water and avoids the risk of mixing concentrated formula with PFAS-contaminated water. If you are using powdered formula and your tap water has PFAS detections, use filtered water (reverse osmosis or NSF P473-certified) to prepare it.

4. Know Your Water Test Results

If you are pregnant or planning pregnancy and have not yet checked your local water system’s PFAS levels, do it now. Enter your ZIP code on our homepage to see EPA UCMR 5 results for your area. Understanding your specific exposure level helps you make proportionate decisions about filtration.

A Note on Medical Advice

This article is an educational overview. Nothing here constitutes medical advice, and individual risks depend on your specific PFAS blood levels, health history, and other factors. If you have specific concerns about PFAS exposure during your pregnancy, discuss them with your obstetrician, midwife, or a physician familiar with environmental health. The NASEM 2022 report is a good reference to share with your provider if they are not familiar with PFAS clinical guidance.

PFAS contamination is widespread but the risk is reducible. Filtering your drinking water is something you can do today. Check your water quality and browse our certified filter reviews to find the right solution for your home.