Pregnancy, breastfeeding, and infrared sauna

Can I use a sauna when I'm pregnant?

Heat can do a lot of good for your health, but there are several things to consider during pregnancy. Saunas, hot tubs and steam baths are not recommended because of the risk of the body overheating.

"There is not enough research on whether overheating could be harmful to the baby. That is why I do not recommend that pregnant women use a sauna," says Siw Hansson Kaulbach, founder of Radiant Health.

Overheating is defined as a core temperature above 39.0°C.

Passive heat stress during pregnancy

In 2018, a systematic review was carried out of 12 studies with a total of 347 participants, looking more closely at heat stress and risk to the foetus. The aim of the review was, among other things, to determine the critical environmental and exposure limits for exercise and/or heat exposure during pregnancy.

The authors took as their starting point what is already known about the subject, namely that:

• Animal studies have shown that hyperthermia during pregnancy can harm the foetus.
• Pregnant women are advised to avoid heat stress such as exercising in hot conditions, hot baths or saunas, because of concern about the risk of reaching a core temperature above the proposed teratogenic threshold of 39.0°C.
• Current guidelines do not define a critical limit for heat stress that should be avoided.

No increased risk was found. However, none of the participants exceeded a core temperature of 39.0°C. The highest core temperature measured during sauna exposure was 37.7°C. The authors concluded that pregnant women can sit in hot/dry saunas, with temperatures up to 70°C and 15% relative humidity, for up to 20 minutes without reaching a core temperature above 39.0°C.

Even so, a lot remains unclear. The authors did not find the critical limit for heat stress that should be avoided, so using saunas during pregnancy is still not recommended because of concern about the risk of reaching a core temperature above 39.0°C. More research is needed.

"Without objective definitions, the terms 'hot' and 'humid' environments are ambiguous and open to a wide range of individual interpretation."

Retrospective studies in humans have shown that a severely raised core temperature during pregnancy increases the risk of malformations. Such overheating has most often occurred because of fever in the first four to six weeks of pregnancy.

Take a warm bath in a regular bathtub instead. This is the recommendation of The American College of Obstetricians and Gynecologists for pregnant women. Most of the upper body is above the water, and the water also gradually becomes cooler, which in turn reduces the chance of overheating.

Six weeks after birth

Another question the founder of Radiant Health often gets is when you can start using an infrared sauna again after giving birth. She recommends waiting for six weeks.

"After both of my births, I waited about six weeks before using a sauna, and I took it a maximum of two to three times a week. I did not do more because you detox in a sauna, and in purely hypothetical terms this could pass into breast milk, even though there are no direct studies on it."

Disclaimer: The content of this article is intended as general information only. Research on infrared heat and red light therapy is still evolving, and individual results may vary. Our products are not intended to diagnose, treat, cure or prevent disease. Contact a doctor or other qualified healthcare professional if you have questions about your own health, diagnosis or treatment.

Text: Trine Dahlman