Saunas and Jacuzzis During Pregnancy: What to Know

Medically Reviewed by Dany Paul Baby, MD on April 11, 2022
5 min read

While using a sauna or a jacuzzi during pregnancy may not seem like a big deal, it can be bad for you and your baby. Yet, you can easily avoid the risks by following a few safety guidelines. Here’s what you need to know.

Getting in a sauna or jacuzzi during pregnancy means exposing yourself to higher-than-usual temperatures. Because your body is going through heavy hormonal changes, this can lead to severe side effects:

Overheating. Saunas hamper your ability to lose heat by sweating. Even though this is not risky normally, it can cause harm if you’re pregnant. For example, overheating can cause nausea and disorientation.

Fainting. While exposed to a high temperature, your body sends more blood to your skin’s surface to cool you down by sweating. Combined with the hormonal changes that come with pregnancy, this can reduce blood flow to your brain — leading to fainting.

Dizziness. Overheating can also make you feel dizzy. Just like fainting, this is caused by a lack of blood flow to your brain. 

Dehydration. The high temperature of a hot tub makes your body sweat much more than usual. And if you’re pregnant, your body may already be lacking some water. The combination of the high temperature and lack of water may cause mild dehydration

To avoid some of these symptoms, make sure to keep hydrated and dress properly. Otherwise, if you start feeling overheated, get out of the sauna or hot tub as soon as possible and try to cool down with a glass of water.

Like fevers, steam rooms and hot tubs can raise your body temperature to 38 degrees Celsius or higher. This can not only take a toll on your body but also seriously affect your baby. 

While related research is limited, studies have pointed out the risk of neural tube defects can increase after fevers during the first trimester. Neural tube defects are serious abnormalities of the brain or spinal cord that can put your baby at risk. 

Because of the lack of research, there’s no way to know if high temperatures have the same effects whether it’s from a fever or a hot tub. Still, it’s best to avoid them to erase any possible chance of neural tube defects.

The most common neural tube defect is spina bifida. This birth defect happens when the baby’s neural tube doesn’t close all the way, and as a result, the backbone, which is supposed to protect the spinal cord, doesn’t form correctly. 

Anencephaly is another defect where the open neural tube is exposed at the base of the skull. It’s one of the most severe birth defects because it causes the baby to be born without parts of their skull and brain.

Other neural tube defects caused by exposure to high temperature during pregnancy include:

  • Encephalocele — When the neural tube doesn't close correctly, it can lead to a sac-like protrusion on the back of the baby's head. While it can be treated with surgery, neurological damage will remain.
  • Hydranencephaly — In rare cases, a failure in the neural tube can lead to parts of the baby's brain being replaced by sacs filled with fluid. This can lead to seizures, deafness, or even death.
  • Iniencephaly — An open neural tube can cause the fusion of some parts of the spine, forcing the baby's head into an unnatural position. It's a lethal defect, but doctors can sometimes spot it on prenatal tests.

Yet, keep in mind that the baby is only vulnerable to neural tube damage during the first six weeks of pregnancy. This means that getting in a hot tub or a sauna after the first trimester is mostly safe for the baby.

If you still want to use a sauna or jacuzzi during pregnancy, there are a few safety measures you should take:

Reduce the water temperature. You can ensure a safe hot tub temperature for pregnancy by cooling the water in the jacuzzi. Ideally, it shouldn’t go above 35 degrees Celsius.

Don’t soak your whole body. Keeping your upper torso, arms, and head out of the water will help you avoid overheating.

Avoid long baths. Your body takes about 10 minutes to raise its temperature to a dangerous number for pregnancy. If you ensure that your time in the hot tub is shorter than that, you’ll avoid most of its side effects.

Watch out for possible discomforts. If you feel dizzy, light-headed, or unusually heated, get out of the water as soon as possible. 

Don’t sit near the heat source. Hot tubs have a small inlet that sends heated water into the jacuzzi. Naturally, sitting close to it will increase your chances of overheating and other side effects.

The only way to remain sure of avoiding all risks both for you and for your baby is to stay away from jacuzzis and saunas. Instead, try other ways to relax like a massage or a warm bath.

If you got into a steam room, jacuzzi, or hot tub during the early stages of your pregnancy, check with your doctor. Though the risk of neural tube defects is low, getting a prenatal test done will help you clear all your doubts.

Birth defect tests usually consist of blood tests and ultrasound checks. Your doctors will also ask you questions regarding your medical history and recent medications you’ve taken. 

In case they detect something abnormal, experts will inform you of all the available options. Some neural tube defects, like spina bifida, can be repaired even while the baby is still inside you.

Still, birth defects are relatively uncommon, so there’s no need to worry until your doctor gives you a proper diagnosis. For example, spina bifida only affects about one out of 2,800 babies in the U.S. 

There’s no way to use a hot tub during pregnancy and be completely safe. If you still want to soak in a hot tub or a jacuzzi during the early stages of your pregnancy, make sure to do it for no longer than 10 minutes.

After the first trimester, you can use hot tubs or saunas without posing any significant risks to your baby. Even then, you should be on the lookout for potential discomforts. If you feel your temperature rising too much, if you feel dizzy, or if to think you're going to faint, get out of the jacuzzi immediately.

You can also take folic acid — a B vitamin that helps prevent major birth defects. Most pregnant women need to take about 400 micrograms of it every day — but check with your doctor to make sure.