Heat and Pregnancy

Explore Other Kids and Climate Health Impacts

Find information on how heat can affect pregnancy. Start by reading the fictional story of a pregnant woman who is affected by extreme heat and learn how similar situations can impact pregnant women across the country. Also get tools to help families prepare and cope with outcomes from extreme heat. Finally, check out the regional spotlight.

On this page:

Climate Change Impacts
Impacts on Pregnancy
More Resources

Sarah's Story

Sarah is pregnant and living on the fourth floor of a city apartment. She does not have air conditioning. During her pregnancy, Sarah is exposed to temperatures that are much higher than normal for prolonged periods. Sarah is worried because she has heard that exposure to heat can increase her risk of having a preterm birth.

Climate Change Impacts

The United States is warming. Since 1970, the continental United States has experienced warming nearly 60% faster than the global average. Puerto Rico has warmed by more than 1°F since 1950.¹
The amount of warming has differed by region, with the greatest temperature increases occurring in the Southwest, upper Midwest, Alaska, and the Northeast.¹
Extreme heat or temperatures much hotter and/or more humid than average was estimated to be responsible for more than 700 deaths per year between 2004 and 2018.¹

Impacts on Pregnancy

As little as one day of high heat increases risk of high blood pressure disorders of pregnancy and related pregnancy complications.²
People who are pregnant experience heat exhaustion, heat stroke, or other heat-related illness more easily than people who are not pregnant. This is because the body of someone who is pregnant must work harder to cool down both herself and her developing baby.³
People who are pregnant require more liquids to remain hydrated, which means they may become dehydrated more easily, especially during days that are hotter than normal.⁴ This interferes with their ability to cool themselves by sweating.³
A pregnant woman’s circulation helps protect her developing baby, but when working in hot or physically demanding conditions, her internal body temperature may rise. In some cases, this has been linked to health problems for the pregnant woman and her developing baby.⁵
When women are pregnant they are in a period of vulnerability, meaning that events that occur during their pregnancy can affect their health later in life such as cardiovascular disease and other chronic illnesses.⁶

What can I do?

DO drink plenty of water.
DO cool down with water and ice.
DO take steps to keep the air in your home cool. Use air conditioning if you have it. Have air conditioning systems cleaned and serviced before heat arrives. Use an electric fan to exhaust hot air from rooms or draw in cooler air. Only use a fan if indoor air temperatures are less than 90°F. Learn how you can use ventilation and shading strategies to help control indoor temperatures and conserve energy during extreme heat.
DO find a location that has air conditioning by dialing 2-1-1 or searching for cooling centers by state, especially if you cannot maintain safe temperatures in your home. Learn more about heat and your health.
DO seek medical care immediately if you or someone you know experiences symptoms like unusually heavy sweating, headache, cramping, shortness of breath, tiredness, weakness, nausea, and dizziness.
DO check the local news for health and safety updates regularly.
DO talk to your healthcare provider about how to safely replace salt and minerals lost through sweating and to create a medication and care plan.
DO eat water-rich foods like fruits and vegetables.

What should I not do?

DON'T engage in strenuous activities.
DON'T spend long periods outside on hot days. Tools like the CDC Heat Risk Dashboard can help you determine if it is safe to be outside.
DON’T use an electric fan in a closed room.
DON’T use electric fans for cooling when the room temperature is in the mid-90s or higher. When it is that hot, electric fans will not prevent heat-related illness.

Regional Spotlight: Heat in the Northeast

The Northeast includes Connecticut, Delaware, District of Columbia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and West Virginia.

Heat waves in the Northeast are becoming more frequent, lasting longer, and becoming more intense. This trend is expected to continue, resulting in an increase in the number of heat-related illnesses and deaths.⁷
The number of nights with above-average temperatures has increased over the last 100 years and is expected to continue to increase, alongside decreases in the number of cold days. Parts of the region have already warmed by more than 2°F since the beginning of the 20th century.⁷
During periods of higher-than-average temperature, nighttime temperatures in the region’s big cities are generally several degrees higher than in surrounding regions, leading to higher risk of heat-related death.⁸
Homes in the Northeast are also less likely to have air conditioning than homes in the South or Midwest.⁹