Heat Exposure Risks in Pregnancy
The short answer
Elevated body temperature (hyperthermia) in early pregnancy has been associated with an increased risk of neural tube defects. Hot tubs and saunas, which can raise core body temperature above 101F (38.3C), should be avoided during pregnancy, especially in the first trimester. Warm baths (not hot) at a comfortable temperature are safe and can be soothing.
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By Age
What to expect by age
The first trimester is the most sensitive period for heat exposure because neural tube development occurs in weeks 3-4. Avoid hot tubs, saunas, and steam rooms. Warm baths where your upper body stays above water are fine. If you used a hot tub before knowing you were pregnant, try not to worry - brief exposure is different from prolonged, repeated use.
Continue to avoid hot tubs and saunas. Warm (not hot) baths are safe and can help with aches and pains. Avoid overheating during exercise - work out in cool environments, stay hydrated, and stop if you feel overheated. Avoid prolonged sun exposure in extreme heat.
Same guidelines apply. Warm baths can be especially soothing for back pain and swelling. Keep the water comfortable, not hot. If you are unsure about the temperature, it should feel warm and comfortable, not hot enough to make your skin red.
What Should You Do?
When to take action
- Taking warm (not hot) baths throughout pregnancy
- Mild sweating during exercise that resolves with rest and hydration
- You were exposed to prolonged high heat before knowing you were pregnant
- You are unsure about safe temperatures for bathing
- You have been in extreme heat and have symptoms of heat exhaustion: heavy sweating, weakness, nausea, rapid heartbeat, or confusion
Sources
Related Resources
Trust your instincts. If something feels wrong, reach out to your pediatrician.
Worrying about your baby means you care. That is a good thing.
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