Pregnancy changes the answer to a lot of ordinary questions, and this is one of them. The concern isn’t the sauna itself. It is your core temperature.
This article gathers what pregnancy health organizations say. It sits under our overview of sauna health benefits. This is general information, not medical advice, and it doesn’t replace your obstetrician or midwife. Ask them before you use a sauna.
Short answer: the cautious advice is to avoid saunas in early pregnancy and to limit them after that, because overheating is linked to a small increase in the chance of certain birth defects. If your provider says a sauna is fine for you, keep sessions short. Ask first.
Why heat is the issue
MotherToBaby, a service of the Organization of Teratology Information Specialists, describes hyperthermia as “a rise in body temperature” that happens when the body takes in more heat than it gives off.
Its fact sheet says studies have linked fever or hyperthermia to a small chance of neural tube defects when it occurs “before the 6th week of pregnancy.” After week 6, it says, high temperatures are “not expected to increase the chance” of those particular defects. For other birth defects, the concern is in “early pregnancy (before week 12).”
On miscarriage it reports mixed findings. Some studies “suggest there might be an increased chance.” Others have not.
Its bottom line on this topic: “Hot tub or sauna use during pregnancy should be limited.”
What other organizations say
| Source | Advice |
|---|---|
| MotherToBaby (2025) | Hot tub or sauna use during pregnancy should be limited |
| March of Dimes (2020) | No more than 15 minutes at a time in a sauna, or 10 in a hot tub |
| CDC (2025) | “If you are pregnant, talk to a healthcare provider before using a hot tub” |
| Cleveland Clinic (2024, 2026) | Check with a provider first; its infrared sauna article cites ACOG that sauna use, especially early in pregnancy, can harm the fetus |
March of Dimes explains its limit: “Some studies suggest that spending too much time in a sauna or hot tub may make your body temperature too high.” It also notes that body temperature runs slightly higher in pregnancy.
The first 12 weeks
Every source that names a window names the early one. That is awkward, because many people don’t know they are pregnant in the first weeks.
A UK general practice page, using guidance in the style of the NHS, puts it this way: “There’s little research on using saunas, jacuzzis, hot tubs and steam rooms during pregnancy.” It adds that a significant rise in core temperature “could be harmful in pregnancy,” “particularly in the first 12 weeks,” and mentions overheating, dehydration, and fainting as the risks.
If you are trying to conceive, that is the practical reason to be careful before a positive test.
The research is older and doesn’t fully agree
Two older papers are often quoted, and they pull in different directions.
A 1981 study in the Canadian Medical Association Journal measured body temperature in 20 nonpregnant women using hot tubs and a sauna. “None of the women were able to remain in the sauna long enough for their temperature to reach 39.9 degrees C.” The authors concluded that usual hot tub use was unlikely to reach it, “although prolonged use may.”
A 2001 review states that sauna bathing “is safe during the uncomplicated pregnancies of healthy women.”
Against those sit the more recent, more cautious recommendations above. I’d give the current guidance from pregnancy organizations more weight than a 1981 study of 20 women. That is my reading. Your provider knows your pregnancy and I don’t.
Other risks that aren’t about the baby
Heat can drop your blood pressure. Dizziness and fainting are more common in pregnancy to begin with, and a faint in a hot room next to a heater is dangerous. Dehydration is the other one.
If your provider says yes
Their instructions come first. The general cautions from the sources here:
- Keep it short. March of Dimes gives 15 minutes as the upper limit.
- Drink water before and after.
- Sit low, where the air is cooler, and near the door. That tip is mine.
- Leave at the first sign of dizziness, nausea, or feeling too hot.
- Never use the sauna alone.
If you own a sauna
It will keep. Pausing costs nothing, and the question goes away after the birth. If you are shopping for one during pregnancy, the home sauna buying guide covers lower-temperature infrared cabins, though the cautions above were written about heat in general and apply to those too.
Bottom line: avoid the sauna in early pregnancy, limit it later, and let your obstetrician or midwife make the call for your case.
Sources
- MotherToBaby (Organization of Teratology Information Specialists), “Fever/Hyperthermia,” February 1, 2025: mothertobaby.org
- March of Dimes, “Exercise during pregnancy,” last reviewed September 2020: marchofdimes.org
- CDC, “What You Can Do to Stay Healthy in Hot Tubs,” May 20, 2025: cdc.gov
- Cleveland Clinic, “6 Possible Benefits of Infrared Saunas,” October 9, 2026, and “Get Your Sweat On: The Benefits of a Sauna,” August 12, 2024: health.clevelandclinic.org
- Collingwood Health Group (UK general practice), “Is it safe to use a sauna or jacuzzi if I’m pregnant?” accessed October 12, 2026: collingwoodsurgery.nhs.uk
- Harvey MA, McRorie MM, Smith DW, “Suggested limits to the use of the hot tub and sauna by pregnant women,” Canadian Medical Association Journal, 1981 (abstract): pubmed.ncbi.nlm.nih.gov
- Hannuksela ML, Ellahham S, “Benefits and risks of sauna bathing,” The American Journal of Medicine, 2001 (abstract): pubmed.ncbi.nlm.nih.gov