Sauna During Pregnancy: Is It Safe? What You Need to Know

Sauna During Pregnancy: Is It Safe? What You Need to Know

If you're pregnant and used to regular sauna sessions, giving it up for nine months sounds rough. But the question of whether sauna is safe during pregnancy doesn't have a simple yes or no answer. It depends on timing, temperature, duration, and your individual health situation.

Here's what the research actually says, what most doctors recommend, and how to make informed decisions about heat exposure while you're expecting.

The Core Concern: Elevated Core Body Temperature

The main risk with sauna during pregnancy isn't the sauna itself. It's what happens when your core body temperature rises above 101-102F (38.3-38.9C) for an extended period. This condition, called hyperthermia, has been associated with an increased risk of neural tube defects during early pregnancy, particularly during the first trimester when the baby's brain and spinal cord are forming.

A traditional sauna at 170-190F can raise your core temperature by 1 to 2 degrees Fahrenheit within 15 to 20 minutes. For a non-pregnant person, this is perfectly safe and even beneficial. During pregnancy, especially in the first 12 weeks, that temperature increase carries more weight.

What Does the Research Say?

The research picture is mixed, which is part of why guidance varies.

Studies from Finland - where sauna use during pregnancy is far more common than in the U.S. - suggest that moderate sauna use doesn't significantly increase birth defect risk. Finnish women have used saunas during pregnancy for generations, and Finland has some of the lowest rates of neural tube defects in the world.

However, these studies come with caveats. Finnish women who sauna during pregnancy tend to use lower temperatures, shorter durations, and have lifelong heat tolerance that most people don't share. The Finnish tradition also involves cooling off frequently, which prevents core temperature from climbing too high.

On the other side, some animal studies have shown that sustained hyperthermia during early development can cause problems. These studies typically used temperatures and durations far beyond what a normal sauna session would produce, but they're part of why medical organizations err on the side of caution.

What Do Doctors Recommend?

Most medical organizations, including the American College of Obstetricians and Gynecologists (ACOG), advise pregnant women to avoid activities that could raise core body temperature above 102F. This applies to saunas, hot tubs, and very hot baths.

In practice, most OB-GYNs in the United States will tell you one of two things:

• Avoid saunas entirely during the first trimester when the risk of neural tube defects is highest
• If you use a sauna later in pregnancy, keep it short (under 10 minutes), keep the temperature moderate (under 150F), and get out immediately if you feel overheated, dizzy, or uncomfortable

Some doctors take a stricter approach and recommend avoiding saunas throughout the entire pregnancy. Others, particularly in Scandinavian countries, are more permissive with experienced sauna users who know their limits.

Trimester-by-Trimester Breakdown

First Trimester (Weeks 1-12): Highest Risk

This is when neural tube development occurs and when hyperthermia poses the greatest theoretical risk. Most healthcare providers recommend avoiding sauna during this period. If you didn't know you were pregnant and used a sauna during early pregnancy, don't panic. Brief, occasional exposure is very different from prolonged, repeated hyperthermia.

Second Trimester (Weeks 13-26): Moderate Caution

The neural tube risk drops significantly after the first trimester. Some doctors will give a cautious green light for short, moderate-temperature sessions during this period. Your body is also better at regulating temperature by this stage.

Third Trimester (Weeks 27-40): Additional Considerations

Late in pregnancy, heat can affect blood pressure and increase swelling. Your body is already working harder to regulate temperature with the extra weight and blood volume. Keep sessions short if your doctor approves, and listen to your body carefully.

If You Do Use a Sauna While Pregnant

If your healthcare provider gives you the go-ahead for modified sauna use, follow these guidelines:

• Keep it short. 10 minutes maximum, not the usual 15 to 20.
• Lower the temperature. Stay at 140-150F rather than the typical 170-190F.
• Sit on the lower bench. It's cooler down there since heat rises.
• Hydrate aggressively. Drink plenty of water before, during, and after.
• Listen to your body. If you feel lightheaded, nauseous, or overly hot at any point, get out immediately.
• Skip the upper bench and steam. Don't pour water on the stones, as the humidity burst raises the perceived heat significantly.
• Never sauna alone while pregnant. Have someone nearby in case you need help.

Safer Alternatives During Pregnancy

If you're missing the relaxation benefits of sauna during pregnancy, there are lower-risk ways to get similar effects:

• Warm baths (not hot). Keep the water at or below 100F. This provides relaxation without significant core temperature increase.
• Infrared sauna at low settings. Some practitioners consider low-temperature infrared sessions (under 120F) to be safer since they warm the body more gently. Still check with your doctor first.
• Foot soaks. Warming your feet in hot water provides surprising relaxation benefits without raising core temperature meaningfully.
• Gentle stretching and breathing exercises. Much of the mental benefit of sauna comes from the forced pause and relaxation. You can replicate that without the heat.

After Pregnancy

Once you've delivered and your doctor clears you for normal activities (usually 4 to 6 weeks postpartum for uncomplicated deliveries), you can return to your regular sauna routine. Many new parents find that sauna becomes even more valuable as a stress relief tool during the demanding early months with a newborn.

If you're breastfeeding, sauna use is generally considered safe. Just make sure you're drinking plenty of water to stay hydrated, since dehydration can affect milk supply.

The Bottom Line

Talk to your OB-GYN. That's the honest answer. Every pregnancy is different, and your doctor knows your specific health situation. Most will recommend avoiding saunas in the first trimester and being cautious in the second and third.

The sauna will still be there after the baby arrives. And when you're ready to get back to it, check out our outdoor saunas and indoor saunas for home setups that make consistent use easy - something you'll really appreciate during those early parenting months when getting to a gym sauna feels impossible.