Health risks after a flood or hurricane while pregnant

What does the evidence say about natural disaster exposure during pregnancy?

1. Floodwater can contain germs, dangerous chemicals, and human and livestock waste. Flooding also increases mosquito populations, and pregnant people are specifically advised to take precautions against mosquito-borne illnesses such as Zika virus and West Nile virus, including protective clothing and an EPA-registered insect repellent. 1
2. Never run a generator, kerosene heater, or grill indoors during a power outage. Carbon monoxide has no color or smell, and it is a poison to both a pregnant person and the baby, which is why detector placement and immediate fresh air matter as much as any other disaster precaution. 1
3. If a home has been affected by floods, mold may be present, and pregnant people or those with a young infant are advised to avoid entering a building with mold damage. Anyone who does touch floodwater should wash the exposed skin with soap and clean water afterward. 2
4. CDC includes emotional health in disaster planning because severe stress is associated with adverse pregnancy outcomes, including preterm birth and low birth weight. This does not predict an individual pregnancy outcome or mean a parent caused a complication. Seek support for overwhelming distress and urgent medical care for signs of labor. 2
5. Natural disasters can bring chemical and pollutant exposure, including lead, on top of infection risk from contaminated food, water, and crowding. Contacting a healthcare provider or Poison Control at 1-800-222-1222 is the recommended step for a suspected harmful exposure rather than guessing at the risk. 3
6. Standing water and wet building materials left after a flood are a breeding ground for viruses, bacteria, and mold, which can cause illness and trigger allergic reactions long after the flood itself has passed. This is general flood-cleanup guidance rather than pregnancy-specific research, so it applies to anyone doing or supervising cleanup. 4

Is natural disaster exposure safe in each trimester?

• First trimester. Early pregnancy doesn't change the core disaster guidance, but miscarriage and ectopic pregnancy are more common in this window and harder to manage away from your usual care team, so keep prenatal records and contact information easy to grab if you need to evacuate.
• Second trimester. By the second trimester, energy and mobility are often at their best, which can make it tempting to help with heavy cleanup, but strenuous disaster cleanup and floodwater contact are still discouraged. Let someone else handle the physically demanding work.
• Third trimester. Late pregnancy adds practical urgency: know your backup delivery location in case your usual hospital is unreachable, keep pregnancy records and due-date information with you, and act on any sign of labor immediately rather than waiting out the disaster.

Disaster health risks at a glance