Pregnancy, breastfeeding, and infrared sauna

Can I use a sauna when pregnant?

There are many health benefits to heat, but during pregnancy, there are several considerations to take into account. Saunas, jacuzzis, and steam baths are not recommended due to the risk of overheating the body.

– There isn't enough research on whether it can be dangerous for the baby due to overheating. Therefore, I do not recommend pregnant women to use saunas, says Siw Hansson Kaulbach, founder of Radiant Health.

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

Passive heat stress during pregnancy

In 2018, a systematic review of 12 studies with a total of 347 participants was conducted to examine heat stress and fetal risk. The goal 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 based their findings on what is known about the subject, such as:

• Animal studies have shown that hyperthermia during pregnancy can harm the fetus.
• Pregnant women are advised to avoid heat stress such as exercising in the heat, hot baths, or saunas, due to concerns about the risk of reaching a core body temperature above the suggested 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 body temperature of 39.0°C. The highest measured core body temperature for 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 with 15% relative humidity – for up to 20 minutes without reaching a core body temperature exceeding 39.0°C.

Nevertheless, much remains unclear. The authors did not find the critical limit for heat stress that should be avoided, and the use of saunas during pregnancy is therefore still not recommended due to concerns about the risk of reaching a core body temperature above 39.0°C. More research is needed.

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

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

Instead, take a warm bath in a regular bathtub. This is The American College of Obstetricians and Gynecologists' recommendation for pregnant women. Here, most of the upper body is above the water. The water also gradually cools down, which further reduces the chance of overheating.

Six weeks after birth

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

– I myself waited about six weeks after both births before using a sauna and did so a maximum of two to three times a week. I didn't do more because you detoxify in a sauna, which hypothetically could pass into breast milk, although there are no direct studies on it.

The article is intended as interesting reading, not medical advice.

Text: Trine Dahlman