Chemical Exposure During Pregnancy

What you need to know about environmental hazards in pregnancy.

caution tape
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Proceed with Caution

If you stopped to think about the many chemicals you come into contact with each day, from cleaning supplies to pesticides, you might be concerned about their effect on your health and the health of your unborn baby. The good news? Many of the chemicals you encounter on a regular basis won't pose a risk to your growing baby.

Chemical exposure can occur in a variety of ways. You can breathe it in, ingest it in foods or beverages, or in some cases, absorb it through your skin. For most hazardous substances, pregnant women must be exposed to a large amount of chemicals for a prolonged period of time for them to be harmful to baby. The truth is, only a few of these substances have been proven to be dangerous during pregnancy. Fortunately there are many ways you can reduce your risk. Here are some simple precautions you can take to keep yourself -- and your home and work environment -- safe.


While lead poses problems for everyone, unborn babies and young children are at the greatest risk. Studies have shown that exposure to high levels of lead during pregnancy may potentially cause problems such as miscarriage, preterm delivery, low birth weight, and, in some cases, developmental delays in infants. Well-documented research has also demonstrated that even small amounts of lead can affect your unborn baby's learning and behavioral development.

This dangerous substance often lurks in your drinking water. Find out if your home has lead pipes, lead solder on copper pipes, or brass faucets (all brass contains some lead), and follow up with your state health department, who can perform a test on your water. The U.S. Environmental Protection Agency (EPA) also recommends running water for 30 seconds before use to reduce lead levels.

To keep potential health problems at bay, it's best to use cold water (which contains less lead than hot water) for cooking and drinking.

Unfortunately you could also be at risk for lead exposure if you live in a structure built before 1978. Most homes constructed earlier have lead-based paint in their interiors. If you believe your home may have a problem, stay away from areas with peeling paint, have someone vacuum up any paint chips or dust to avoid potential inhalation or ingestion, and employ a professional to scrape and repaint while you leave the premises. Sanding or scraping lead paint can contaminate the air with lead dust, which can be harmful to you and your unborn baby.

Other sources of lead may include crystal glassware and some imported or antique ceramics, so avoid frequent use of these items. If you suspect a problem, test the items with a lead kit you can purchase at your local hardware store. Though scented candles are pretty and smell good, it's a good idea not to use them -- some of their wicks may contain lead, which can be released into the air when burned.

Fish and Mercury

You may think of fish as a healthy, low-fat, high-protein food choice. But when it comes to mercury exposure, fish are a common culprit. The U.S. Food and Drug Administration (FDA) advises pregnant women to abstain from eating fish that have high mercury levels, such as shark, swordfish, king mackerel, and tilefish. New moms who are breastfeeding should also beware, since these fish can contain enough mercury to harm your baby's developing nervous system and motor skills.

The FDA and the EPA advise pregnant women to limit their consumption of tuna. Mercury levels in this fish can vary, with fresh tuna and canned albacore (white tuna) generally containing higher amounts than canned light tuna. So consume 6 ounces or less per week. To protect yourself while still enjoying all of the health benefits of fish, limit your total fish consumption to 12 ounces a week and opt for fish with lower mercury levels. Farmed salmon, flounder, perch, sole, cod, and catfish are all good choices. If you have a fisherman in the family, don't eat any locally caught fish unless your area health department has deemed it safe for consumption.

Avoiding Arsenic

Aside from its dramatic appearances in murder mysteries, arsenic may be lurking in your own backyard. In fact, most outdoor wooden structures, such as decks, play sets, and picnic tables are made with pressure-treated lumber that contains an arsenic-based preservative called chromated copper arsenate. High levels of this poison have been linked to various cancers and diabetes, as well as miscarriage and stillbirth. (As of June 1, 2004, new federal regulations will prohibit the use of this lumber, but stores may still sell older sets from their inventory. So even if your furniture is new, it may still contain arsenic.)

Because arsenic may be found on the surface of these items, wash your hands after touching them and cover picnic tables with a plastic cloth before dining. Avoid pressure-washing these products and have them treated each year with a polyurethane sealant to help prevent arsenic exposure.

High levels of arsenic can also be found near some hazardous waste sites and agricultural areas, where older arsenic-based fertilizers may still be in the soil. In some states, high levels of arsenic are found in rock, which can leach into soil and drinking water. Western areas tend to have higher arsenic levels, as do certain parts of the Midwest and New England. If you think you live in an area with arsenic trouble, have your well water tested, drink bottled water, and limit hand contact with soil. Your local public health department can also provide you with further information and testing options.

Pesticide Problems

While there is no proof that exposure to small amounts of pesticides at home pose a risk to the fetus, they are still poisonous and should be avoided whenever possible. Some studies have shown that large amounts of pesticides can contribute to problems such as miscarriage, preterm delivery, and birth defects. In fact, a new Columbia University study found that mothers who had heavy exposure to two commonly used insecticides had smaller babies than mothers who had less insecticide exposure. Reduce your risk by controlling pests with less toxic options, such as boric acid. However, if you must use pesticides, adhere to the following guidelines:

  • Have someone else apply the chemicals while you leave the area for several hours.
  • Remove foods, dishes, and utensils before the chemicals are applied. Afterward, have someone open the windows and thoroughly wash off all surfaces on which food is eaten or prepared.
  • If pesticides are used outdoors, close all windows and turn off air conditioning to prevent fumes from coming into the house.
  • Wear rubber gloves when gardening to prevent skin contact with soil.

Solvent Safety

If you've ever painted your walls, you've probably worked with solvents. Solvents are chemicals that dissolve other substances and may be found in alcohols, paint thinners, household cleaners, and varnish removers.

A Canadian study found that women who were exposed to solvents during their first trimester of pregnancy were 13 times more likely than unexposed women to have a baby with a major birth defect. Studies have also shown that women exposed to high levels of solvents called glycol ethers were almost three times more likely to miscarry than unexposed women.

If you're pregnant and working with solvents, read labels carefully and avoid toxic products (such as some oven cleaners). It's also best to work in a well-ventilated area, wear appropriate protective equipment, such as gloves, and never eat or drink in the area.

Most likely, your home is free of environmental hazards that could harm your baby. But by taking some simple precautions to minimize your exposure to potential hazards, you can protect your baby from possible risks.

Dr. Schwarz is an obstetrical consultant to the March of Dimes. He is also past president of the American College of Obstetricians and Gynecologists; Vice Chairman for Clinical Services, Department of Obstetrics and Gynecology, Maimonides Medical Center; Emeritus Distinguished Service Professor of Obstetrics and Gynecology, SUNY Downstate Medical Center, both in Brooklyn.

Originally published in American Baby magazine, May 2004.

All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.

All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your won health or the health of others.

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