Extreme heat during pregnancy: What to know to stay safe
As dangerously high temperatures continue to grip much of the United States, the Centers for Disease Control and Prevention says pregnant women should take extra precautions because pregnancy increases the risk of heat-related illness.
According to the CDC, pregnancy makes it harder for the body to stay cool because it must work harder to cool both the mother and the developing baby.
Pregnancy also makes women more likely to become dehydrated, making it more difficult for the body to cool itself through sweating and increasing the risk of heat exhaustion, heat stroke and other heat-related illnesses.
Research suggests prolonged exposure to extreme heat during pregnancy may increase the risk of certain complications.
A 2024 study published in JAMA Network Open, which analyzed more than 53 million births in 50 U.S. metropolitan areas, found that rates of preterm and early-term births increased slightly after four consecutive days of extreme heat. Researchers found the association was stronger during longer and more intense heat waves.
The CDC says heat exposure during any trimester has been associated with adverse pregnancy outcomes, including preterm birth, stillbirth and low birth weight. The agency also says exposure to extreme heat during the first trimester may increase the risk of certain birth defects.
How to stay safe during extreme heat
The CDC recommends pregnant women drink more water than usual and not wait until they are thirsty to drink water. According to the agency, dehydration makes it harder for the body to cool itself through sweating.
The agency also advises staying in air-conditioned places as much as possible and limiting outdoor activities during the hottest part of the day. If you need to be outside, wear lightweight, loose-fitting clothing and take frequent breaks in the shade or indoors.
The Environmental Protection Agency encourages checking local weather forecasts and heat advisories before spending time outdoors.
The CDC also recommends pregnant women who sweat heavily talk with their healthcare provider about how to replenish electrolytes, noting that drinking water alone may not always be enough.
Signs of heat-related illness
According to the CDC, pregnant women should watch for signs of heat-related illness, including dizziness, headache, nausea or vomiting, muscle cramps, heavy sweating, weakness, a rapid heartbeat and fainting.
Confusion, loss of consciousness or a very high body temperature may be signs of heat stroke, a life-threatening medical emergency that requires immediate treatment, according to the CDC.
With dangerous heat expected to continue across parts of the country, the CDC recommends pregnant women take extra precautions to stay cool, stay hydrated and avoid prolonged exposure to high temperatures.
