In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure to conditions following a natural disaster may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.

What could I be exposed to in a natural disaster that may affect my pregnancy?

Vaccinations are given to protect people from serious diseases. Vaccinations that you might be given following a natural disaster include hepatitis A, hepatitis B, and/or tetanus. Your health care providers or the health authorities may recommend other vaccinations. For more information, please see the MotherToBaby fact sheet on vaccines at

There is a risk of infection after a natural disaster. Drinking contaminated water is a risk for infection. Mosquitoes or other insects are also a risk for infection. Follow the recommendations from health authorities to avoid risk. If you think you have an infection, talk to your health care provider right away. Be sure to follow your healthcare provider’s advice on treating your infection. Drink plenty of liquids when you have an infection or other illness to help keep you hydrated.

It may be necessary to take medicine after a natural disaster if you have an infection or other illness. If you need to take medicine, for any reason, tell your health care provider that you are pregnant so that you get the medicine that is best for you during your pregnancy. Contact MotherToBaby ( to get details about your specific medication(s).

Insect Repellent
Using insect repellent is an important way to help protect from infections spread by mosquitoes. A bite from an infected mosquito could give you a serious illness such as West Nile or Zika virus. The most common active ingredient in insect repellent is DEET. Only about 6-8% of the DEET put on your skin gets into your body. This probably means that very little DEET would get to the baby. Other ways to lower your chance of being bitten by a mosquito include wearing long pants, long sleeved shirts, a hat, and shoes when possible. For more information, see the MotherToBaby Fact sheets on West Nile virus (, Zika (, DEET ( and insect repellents (

Cleaning Agents
When used as directed on the label, common household cleaning agents are not expected to increase the risks to your pregnancy. To help reduce topical exposure wear the type of gloves recommended on the product label.

If you think that you may have been exposed to harmful chemicals and you have symptoms or you have general concerns, contact your health care provider as soon as possible.

If you have been exposed to lead, talk to your health care provider about your concerns. A blood test can tell if the level is high. MotherToBaby has a fact sheet on lead and pregnancy at

The water supply may not be clean or safe to drink. Local authorities will tell you if your water supply is safe to drink or to use for cooking or bathing. It may be recommended to drink bottled water. If bottled water is not available, use boiled water, if local public health departments says this is okay. Bringing water to a rolling boil for 1 minute will kill most disease-causing organisms, but it will not remove chemicals. Do not use water that has been treated with iodine unless you do not have bottled water and cannot boil your water. If you do not have clean water for washing hands, use alcohol-based hand sanitizers.

Stress is the way your body reacts to something that is unusual, dangerous, unknown or disturbing. When under stress, your body makes physical and chemical changes. Some of the symptoms of stress can include chest pain, rapid heart rate, breathing problems, headaches, vision problems, confusion, anxiety, guilt, grief, denial, fear, or worry. For more information about stress and pregnancy, please see the MotherToBaby fact sheet at

Molds are fungi that can be found both indoors and outdoors. They grow best in warm, damp, and humid places. Mold can be many different colors and usually grows in damp or water damaged areas. Most molds won’t make you sick, but some molds can produce substances, called toxins, that can cause health problems. Mold exposure can cause symptoms in some people such as allergic reactions including stuffy nose, eye irritation, rashes, and wheezing, and possibly fever or shortness of breath. Not everyone will have these symptoms. For more information on mold and pregnancy, see the MotherToBaby fact sheet at

What about breastfeeding?

If possible, it is best to keep breastfeeding even after a natural disaster. Breast milk can help protect babies from infections. Breastfeeding costs less than bottle-feeding. It is more convenient because there are no bottles to wash or formula to buy, mix, heat or refrigerate. If you are breastfeeding during a natural disaster, there is no need to worry about finding safe, clean water to mix formula or to wash bottles. Breastfeeding also can be soothing and reduce stress for both a mother and her baby.

MotherToBaby has fact sheets about breastfeeding after a natural disaster (, as well as many exposures which include information about breastfeeding (