Radiation and pregnancy

Radiation is a kind of energy. It travels as rays or particles in the air. Radiation can attach itself to materials like dust, powder or liquid. These materials can become radioactive, which means that they give off radiation. 

You are exposed to (come in contact with) small amounts of radiation nearly every day. This radiation comes from natural sources (like sun rays) and man-made sources (like microwave ovens and medical X-rays). These kinds of radiation don’t cause serious harm. However, radiation emergencies, like a nuclear power plant accident, may expose you to larger, more dangerous amounts of radiation. This may cause harm to you and your baby.

If you think you've been exposed to large amounts of radiation, tell your health care provider immediately.

How can you protect yourself and your baby from radiation during pregnancy?

Tell any health care provider you see, including your dentist, that you’re pregnant before you get an X-ray or other tests that use radiation, like computed tomography (also called CT or CAT scan). CT scans use special X-ray equipment and powerful computers to make pictures of the inside of your body. Most X-rays are safe to get during pregnancy. But if you’re pregnant and need an X-ray or a CT scan of your belly, your provider may want to wait until your baby’s born, modify the test to reduce the amount of radiation or use another test that doesn't use radiation, like ultrasound. You and your provider can decide what treatment is best for you.

If you work with radiation at your job, talk to your boss. Tell him that you’re pregnant. You may be able to change job responsibilities to help keep you and your baby safe during pregnancy.

If you've been in a radiation emergency with possible exposure to large amounts of radiation, follow these guidelines from the Centers for Disease Control and Prevention (also called CDC):

  1. Get inside. Get to the middle of a building or a basement, away from doors and windows. Bring pets inside.
  2. Stay inside. Close and lock windows and doors. Take a shower or wipe any exposed parts of your body with a damp cloth. Drink bottled water and eat food in sealed containers.
  3. Stay tuned. Use radios, TVs, computers and mobile devices to get current information from officials in your area.

If you think you’ve been exposed to large amounts of radiation, tell your health care provider immediately.

How does radiation affect you and your baby during pregnancy? 

During pregnancy, your body protects your baby from most radiation that you’re exposed to every day. Most babies born to moms who come in contact with low amounts of radiation during pregnancy aren’t at increased risk for birth defects. A birth defect is a health condition that a baby has at birth. Birth defects change the shape or function of one or more parts of the body. They can cause problems in overall health, in how the body develops, or in how the body works.

If you swallow or breathe in radioactive material during pregnancy, it can get into your bloodstream and pass through the umbilical cord to your baby. It also can build up in areas of your body that are close to your uterus (womb), such as your bladder. The effect on your baby depends on the amount of radiation your body takes in, the kind of radiation it is, and the length of time you’re in contact with it. Your baby is most sensitive to radiation between 2 and 18 weeks of pregnancy.  Exposure to radiation during pregnancy can:

  • Slow your baby’s growth
  • Cause birth defects
  • Affect your baby’s brain development
  • Cause cancer in your baby
  • Cause miscarriage. This is the death of a baby in the womb before 20 weeks of pregnancy.

Exposure to large amounts of radiation, equal to having more than 500 chest X-rays at one time, is not common. It did happen to women in Japan after the atomic bombs dropped on Hiroshima and Nagasaki in 1945. If you do come in contact with large amounts of radiation, you may not feel sick, but the radiation may cause serious problems in your baby

Exposure to extremely large amounts of radiation, equal to having more than 5,000 chest X-rays at one time, also is not common. It did happen to women in the Chernobyl nuclear power plant accident in the Ukraine in 1986. If you do come in contact with extremely large amounts of radiation, you may show signs of radiation sickness, including:

  • Vomiting, diarrhea, bloody stools
  • Fever
  • Fatigue (being really tired)
  • Hair loss

Contact your health care provider immediately if you think you’ve been exposed to large amounts of radiation. 

Last reviewed: December, 2014