Mercury is a metal. If you’re exposed to high levels of mercury during pregnancy, it can cause real problems for you and your baby.

Mercury can damage many parts of your body, including the nervous system, lungs and kidneys. It also can cause hearing and vision problems. The seriousness of the damage depends upon how much mercury you’re exposed to.

Babies who are exposed to mercury in the womb can suffer brain damage and affect your baby’s hearing and vision.

How are you exposed to mercury?

Mercury has several forms:

  • It’s the shiny, silvery-white liquid used in thermometers. It’s also used in some dental fillings and in some light bulbs.
  • It can be a colorless, odorless vapor in the air. It’s released into the air through industrial processes, like burning waste or burning coal in power plants.
  • Mercury in the air falls back to earth and builds up in oceans, lakes, rivers and streams. The fish in these waters absorb the mercury. If you eat these fish, you can be exposed to mercury.

You can be exposed to mercury through:

  • Your skin, by touching it
  • Through the air, by breathing it in
  • By eating or drinking food or water contaminated with it

How can you limit or prevent exposure to mercury? 

Follow these tips to help you stay away from mercury during pregnancy:

  • Don’t eat fish that contain high amounts of mercury. And limit fish with lower amounts.
  • If you work in a job where you may be exposed to mercury, talk to your employer about safety precautions. Ask if you can switch to a different position or task during pregnancy.
  • If you need to have a tooth filled , talk to your dentist about filling options. The Food and Drug Administration says that mercury fillings are safe for most people, including pregnant women. But you may be able to have a filling that doesn’t contain mercury. Don’t have any mercury fillings removed unless they are broken or damaged.
  • Ask an adult who’s not pregnant to throw away any broken thermometers, fluorescent light bulbs or high-intensity light bulbs. Store these items in a way that prevents them from breaking, and don’t let children handle them. Don’t use a vacuum cleaner to clean spilled mercury.

For specific information, see the recommendations provided by the U.S. Environmental Protection Agency.

Last reviewed July 2012

See also: Environmental risks and pregnancy

Most common questions

Is air travel safe during pregnancy?

If your pregnancy is healthy, it’s usually safe to travel by plane. Follow these tips when traveling by air:
  • Ask your airline if they have a cut-off time for traveling during pregnancy. You can fly on most airlines up to 36 weeks of pregnancy. But if you’re flying out of the country, the cut-off time may be earlier.
  • If you’ve had morning sickness during pregnancy, ask your provider if you can take medicine to help with nausea.
  • Book an aisle seat so you don't have to climb over other passengers when you need to get up to use the restroom or walk around. Try sitting towards the front of the plane where the ride feels smoother.
  • Drink plenty of water. Don’t drink carbonated drinks, such as soda. And don’t eat foods, such as beans, that may cause gas.Gas in your belly can expand at high altitudes and make you feel uncomfortable.
  • Fasten your seat belt when you’re in your seat. This can help keep you from getting hurt in case of turbulence. Turbulence happens when the air around a flying plane causes a bumpy ride.
  • Wear loose, comfortable clothing. Flex your ankles during the flight, and take a walk when it's safe to leave your seat. Doing these things can help your blood flow and lower your risk of deep vein thrombosis (DVT), a blood clot inside a vein. Sitting for long stretches of time during any kind of travel raises your chances of having DVT. Ask your health care provider if you should wear support stockings during your flight. They may help prevent DVT. But if you have diabetes or problems with blood circulation, you probably shouldn’t wear them.
  • Tell the flight attendant if you feel sick or very uncomfortable during your flight. Contact your health care provider as soon as you can.

Is it safe to get or have a tattoo during pregnancy?

It's best to wait until after having your baby to get one. Here's why: Hepatitis B, a dangerous liver infection, and HIV/AIDS are two of many diseases that can be passed along through bodily fluids. This means you can catch these diseases if you get a tattoo from someone who uses a dirty needle. And you can pass these diseases along to your baby during pregnancy.

We don't know how tattoo dyes and inks affect a developing baby. Small amounts of chemicals that might be harmless to an adult can have a much bigger impact on a growing baby.

Most healthcare providers will give an epidural to a woman with a tattoo on her lower back. But they may decide not to if the tattoo is recent and fresh. If you have a tattoo on your back and are considering getting an epidural for pain relief during childbirth, find out what the hospital's policy is before you're admitted.

Is it safe to get spa treatments during pregnancy?

Some spa treatments are safe. Others may be more painful than usual. And some - like mud baths - are a bad idea while you're pregnant.

Any spa treatments that raise your body temperature (like mud baths, hot wax and seaweed wraps) are almost always unsafe during pregnancy. Steam rooms, hot tubs, and saunas also raise your body temperature. They can make you dehydrated and overheated. This can be dangerous for you and your baby. Avoid these treatments while you're pregnant.

Be careful with skin treatments like facials and body scrubs. During pregnancy, your skin changes a lot and may be extra sensitive. Before you cover your whole body with a product, test it on a small area of skin to be sure it doesn't irritate.

Getting your eyebrows done and having your bikini line waxed are usually safe during pregnancy, but they may feel more painful to your sensitive skin.

©2013 March of Dimes Foundation. The March of Dimes is a non-profit organization recognized as tax-exempt under Internal Revenue Code section 501(c)(3).