Is Tap Water Safe to Drink During Pregnancy?

The Question Every Pregnant Woman Should Ask

Staying hydrated during pregnancy is not optional. The American College of Obstetricians and Gynecologists recommends that pregnant women drink 8 to 12 cups — 64 to 96 ounces — of water every day. Water supports the increased blood volume of pregnancy, helps form amniotic fluid, carries nutrients to the baby, and flushes waste products from both mother and child.

The question is not whether to drink water. The question is whether the water coming out of your tap is safe to drink in those quantities, every day, for nine months.

The honest answer is: it depends on where you live and what is in your water. U.S. tap water is generally regulated and treated, but "regulated" does not mean free of all health risks. Several contaminants that are legal under current federal standards have been linked to pregnancy complications, developmental harm, and adverse birth outcomes in peer-reviewed research.

Here is what you need to know.

Why Pregnancy Changes the Equation

Pregnant women and developing fetuses are not just smaller adults. They are biologically different in ways that make certain contaminants more dangerous.

During pregnancy, blood volume increases by up to 50 percent, meaning more water — and whatever is dissolved in it — is circulating through the body. The placenta, while protective against many threats, does not filter out most chemical contaminants. Lead, arsenic, nitrate, PFAS, and disinfection byproducts can all cross the placental barrier and reach the developing fetus.

Fetal development is exquisitely sensitive to chemical disruption, particularly during the first trimester when organ systems are forming. Exposures that would cause minimal harm to an adult can have lasting effects on a developing nervous system, endocrine system, or immune system. The fetus cannot detoxify chemicals the way an adult liver can, and it cannot excrete them as efficiently.

This is why the EPA and CDC consistently identify pregnant women, fetuses, and infants as among the most vulnerable populations when it comes to drinking water contaminants.

The Contaminants That Matter Most During Pregnancy

### Lead

Lead is perhaps the most well-documented drinking water hazard for pregnant women. It crosses the placental barrier readily, and there is no known safe level of lead exposure for a developing fetus. Lead exposure during pregnancy has been linked to:

• Increased risk of miscarriage and preterm birth
• Low birth weight
• Impaired brain development and lower IQ in children
• Behavioral and learning problems that persist into childhood and adolescence

Lead enters drinking water primarily through aging infrastructure — lead service lines, lead solder in plumbing, and brass fixtures that contain lead. This is a problem in homes built before 1986, when lead solder was banned, and in communities with older water distribution systems. The EPA's action level for lead is 15 parts per billion, but the CDC states that there is no safe level of lead exposure for children, and the same principle applies to fetuses.

Practical step: Always use cold water for drinking and cooking during pregnancy. Hot water dissolves lead from pipes more readily than cold water. If water has been sitting in pipes for several hours, run the cold tap for 30 seconds to 2 minutes before using it.

### PFAS (Per- and Polyfluoroalkyl Substances)

PFAS — the "forever chemicals" — have been detected in the drinking water of an estimated 45 percent of U.S. tap water supplies, according to the USGS. Research published in peer-reviewed journals has linked PFAS exposure during pregnancy to:

• Higher risk of high blood pressure and pre-eclampsia
• Reduced birth weight
• Disrupted immune development in infants
• Altered thyroid function in pregnant women

PFAS are particularly concerning because they accumulate in the body over time and are transferred from mother to fetus through the placenta and from mother to infant through breast milk. The EPA set maximum contaminant levels for six PFAS compounds in 2024, but many more PFAS types remain unregulated.

### Nitrate

Nitrate is one of the most widespread contaminants in U.S. drinking water, particularly in agricultural regions. It enters water supplies from fertilizer runoff, septic systems, and animal waste. While the EPA's legal limit for nitrate is 10 milligrams per liter (mg/L), research has raised concerns about health effects at lower concentrations.

For pregnant women, nitrate exposure has been associated with neural tube defects and other birth defects. For infants under six months, nitrate above 10 mg/L can cause methemoglobinemia (blue baby syndrome), a potentially fatal condition where the blood loses its ability to carry oxygen. This is why the EPA's limit was specifically set to protect infants — and why pregnant women and new mothers should pay particular attention to nitrate levels in their water.

### Arsenic

Arsenic occurs naturally in the geology of many U.S. regions and has no taste, odor, or color. It is a known human carcinogen, and research has linked arsenic exposure during pregnancy to:

• Increased risk of miscarriage and stillbirth
• Low birth weight and preterm birth
• Impaired immune development in infants
• Neurological effects including lower IQ and developmental delays

The EPA's legal limit for arsenic is 10 parts per billion, but the EWG's health guideline is 0.004 ppb — 2,500 times stricter — based on cancer risk calculations. Communities in the Southwest, Midwest, and parts of New England are at highest risk.

### Disinfection Byproducts

Chlorine is added to municipal water to kill bacteria and viruses — a critical public health measure. But chlorine reacts with naturally occurring organic matter in water to form disinfection byproducts (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs). Some research has linked high DBP exposure during pregnancy to:

• Increased risk of miscarriage
• Low birth weight
• Neural tube defects

DBPs are present in virtually all chlorinated municipal water supplies. The EPA regulates them, but at levels that some researchers argue are not protective enough for pregnant women.

A Practical Framework for Pregnant Women

The goal is not to avoid tap water — adequate hydration is essential. The goal is to reduce exposure to the specific contaminants that pose the greatest risks.

Step 1: Find out what is in your water. Enter your ZIP code at ewg.org/tapwater to see the contaminants detected in your local water supply and how they compare to health-based guidelines. If you have a private well, get it tested by a certified lab.

Step 2: Use cold water, never hot, for drinking and cooking. Hot water dissolves lead and other metals from pipes more readily. This is one of the simplest and most effective precautions you can take.

Step 3: Flush your tap before drinking. If water has been sitting in your pipes for more than a few hours, run the cold tap for 30–60 seconds before using it. This flushes out water that has been in contact with pipes and fixtures.

Step 4: Consider filtration. The type of filter matters enormously. For broad protection against the contaminants most relevant to pregnancy:

A whole-house filtration system addresses all of these contaminants at the point of entry, ensuring that every tap in your home — including the shower, where DBPs can be inhaled as steam — delivers treated water.

Step 5: Talk to your OB or midwife. If you have specific concerns about your water quality, bring your EWG report or well water test results to your prenatal appointments. Your provider can help you assess the level of risk and whether additional precautions are warranted.

The Bottom Line

Most U.S. tap water is treated and regulated, and drinking it during pregnancy is generally safer than not drinking enough water. But "generally safe" is not the same as "free of risk." Lead, PFAS, nitrate, arsenic, and disinfection byproducts are real concerns that the research takes seriously — and pregnant women have good reason to take them seriously too.

The most important thing you can do is know what is in your water. From there, targeted filtration can address the specific contaminants of concern in your area.

Get your free personalized water report from FranklyH2O. We pull the latest EPA data for your ZIP code and give you a plain-language summary of what is in your water — so you can make informed decisions for yourself and your growing family.

Sources: American College of Obstetricians and Gynecologists (ACOG), Centers for Disease Control and Prevention (CDC), U.S. Environmental Protection Agency (EPA), U.S. Geological Survey (USGS), Environmental Working Group (EWG), National Institutes of Health (NIH).