Pregnancy transforms the body in profound ways—including how it regulates temperature. If you've been enjoying infrared sauna sessions and have recently learned you're pregnant, or if you're planning pregnancy and wondering about sauna safety, you're asking the right question. The American College of Obstetricians and Gynecologists (ACOG) has clear guidance on maternal hyperthermia and sauna use, and understanding this evidence matters for both you and your developing baby.
At Peak Saunas, we believe in evidence-based wellness. Infrared saunas offer genuine health benefits for many people—but pregnancy is a special circumstance that demands a reassessment of heat exposure practices. This article walks you through ACOG's position on sauna use during pregnancy, explains the biological risks of overheating, and offers practical guidance for staying safe while maintaining your wellness routine.
Understanding ACOG's Stance on Heat Exposure During Pregnancy
The American College of Obstetricians and Gynecologists does not explicitly forbid sauna use during pregnancy. However, their clinical guidance emphasizes avoiding maternal core temperature elevation, especially during the first trimester.
The concern centers on a well-documented biological fact: elevated maternal core temperature—particularly above 38.9°C (102°F) in the first 13 weeks of pregnancy—has been associated with increased risk of neural tube defects and other birth defects in epidemiological studies. This risk appears highest when hyperthermia occurs during the critical window of fetal neural development (weeks 3–8).
ACOG's general recommendation is that pregnant individuals should avoid activities or exposures that raise core temperature significantly, especially in the first trimester. This includes:
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Prolonged exposure to very hot environments
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Strenuous exercise in heat
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Hot tubs and saunas at high temperatures
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Fever or heat-related illness
The key word here is "significantly." ACOG acknowledges that brief, mild temperature elevations during normal daily activities pose minimal risk. The hazard appears specific to sustained hyperthermia—the kind that raises core temperature substantially and keeps it elevated.
How Infrared Saunas Affect Core Temperature Differently Than You Might Expect
A critical point for infrared sauna users: infrared saunas raise core temperature differently than traditional Finnish saunas, and this distinction matters for pregnancy safety.
Recent research provides some clarity. In a study of 10 healthy women using infrared sauna, tympanic (core) temperature rose an average of 1.05°C above baseline during a typical infrared sauna session—a statistically significant increase, though the study noted that this occurred in young, healthy, non-pregnant women during a single acute exposure (Hussain et al., 2022).
What's important to understand: infrared saunas operate at lower air temperatures (typically 40–60°C or 104–140°F) compared to traditional Finnish saunas (70–100°C or 158–212°F), yet they can still raise core temperature substantially because infrared radiation penetrates the skin and heats the body from within. The lower ambient air temperature may create a false sense of safety—you feel less uncomfortable than you would in a hotter, more obviously steamy environment, but your core temperature may still be climbing.
For a pregnant person, especially in the first trimester, this is a crucial distinction. A sauna that feels "mild" may still be driving core temperature upward in ways that ACOG guidance suggests avoiding.
First Trimester: When the Risk Is Greatest
The first trimester (weeks 1–13) is when fetal neural tube development is occurring and when ACOG cautions most strongly against maternal hyperthermia. During this period, the fetus is most vulnerable to teratogenic effects from sustained temperature elevation.
If you are in your first trimester and have been a regular infrared sauna user, here's what we recommend:
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Discuss your sauna use with your obstetrician. Provide specific details: how often you use the sauna, at what temperature, for how long, and how you feel during and after sessions. Your OB-GYN can assess your individual risk.
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Consider pausing infrared sauna use through the first trimester. This is the most conservative, evidence-aligned approach. Many pregnant individuals find other heat-based relaxation safe alternatives, such as warm (not hot) baths or prenatal yoga.
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If you continue sauna use, limit duration and intensity. Some pregnant individuals and their healthcare providers agree that very brief exposures (5–10 minutes) at lower infrared sauna temperatures (around 40–45°C / 104–113°F) may carry lower risk than longer, hotter sessions. However, even this should be done under medical supervision.
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Monitor how you feel. Dizziness, excessive sweating, nausea, or a sense of overheating are signs to exit the sauna immediately. Pregnant individuals have a lower heat tolerance than non-pregnant individuals, partly due to expanded blood volume and altered thermoregulation.
Second and Third Trimester: Lower but Persistent Caution
After the first trimester, the absolute risk from mild hyperthermia decreases, since the critical window for neural tube defects has passed. However, ACOG still advises caution in the second and third trimesters for several reasons:
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Pregnancy itself alters thermoregulation. Pregnant individuals have higher baseline core temperature, expanded blood volume, and reduced ability to dissipate heat efficiently. What might be a safe temperature rise for a non-pregnant person could be more stressful during pregnancy.
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Risk of dehydration and orthostatic hypotension. Heat exposure increases fluid loss through sweating. Dehydration during pregnancy can trigger contractions, reduce placental blood flow, and cause dizziness and fainting.
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Fetal hyperthermia risk. While fetal neural development is complete by the second trimester, sustained maternal hyperthermia can still stress the fetus and increase heart rate, potentially triggering preterm labor if severe enough.
Many OB-GYNs suggest that if a pregnant individual has been cleared to use a sauna in the second or third trimester, sessions should be:
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Brief (10–15 minutes maximum)
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At lower temperatures (ideally 40–50°C / 104–122°F for infrared)
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Infrequent (once per week or less, not daily)
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With hydration: drink plenty of water before, during, and after
Practical Infrared Sauna Alternatives for Pregnancy Wellness
If you love the relaxation and wellness benefits of sauna but want to be extra cautious during pregnancy, several alternatives can offer similar benefits with lower thermal risk:
Warm (not hot) baths. A bath at body temperature or slightly warmer (37–38°C / 98.6–100.4°F) can promote relaxation and muscle ease without the risk of significant core temperature elevation. Epsom salt soaks add muscle-relaxing magnesium. infrared sauna for muscle recovery
Prenatal yoga and gentle stretching. Heat may aid flexibility and recovery, but movement and mindfulness offer their own wellness benefits without hyperthermia risk.
Dry infrared therapy blankets or pads at low settings. Some pregnant individuals use low-intensity far-infrared blankets (set to warm, not hot) for localized muscle relief. Always discuss with your OB-GYN and use for brief periods only.
Massage and myofascial release. Prenatal massage is safe and can relieve the muscle tension and discomfort that many pregnant people experience.
For more information on wellness practices during pregnancy, explore our comprehensive wellness blog.
Communicating with Your Healthcare Provider
The safest path forward is a conversation with your obstetrician. Come prepared with honest information:
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How often have you been using the sauna?
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At what temperature and for how long per session?
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How long have you been a regular user?
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Have you experienced any symptoms (dizziness, excessive heat sensation, nausea) during sauna use?
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Are there specific wellness goals you were hoping the sauna would support (stress relief, muscle tension, sleep)? infrared sauna for better sleep
Your OB-GYN may:
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Clear you to continue with specific limits (temperature, duration, frequency)
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Recommend a pause during the first trimester specifically
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Suggest alternatives tailored to your health history and pregnancy circumstances
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Monitor you closely if you have any pregnancy complications (gestational diabetes, preeclampsia, preterm labor risk) that would make heat exposure riskier
No single recommendation fits everyone. Individual factors—your baseline health, how your pregnancy is progressing, your heat tolerance, and your risk factors—all matter.
Key Takeaways: Infrared Sauna and Pregnancy Safety
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ACOG cautions against maternal hyperthermia, especially in the first trimester. While sauna use is not absolutely forbidden, sustained core temperature elevation above 38.9°C during early pregnancy carries theoretical risk of birth defects.
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Infrared saunas raise core temperature despite their lower ambient temperature. Research shows a meaningful rise in core temperature during typical infrared sessions, even though they feel less intense than traditional saunas.
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The first trimester is when caution is highest. This is when fetal neural development is most vulnerable. Many pregnant individuals and their OB-GYNs agree that pausing sauna use through the first 13 weeks is the most prudent approach.
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Pregnancy alters thermoregulation. Pregnant individuals have higher baseline temperature, reduced heat dissipation, and lower heat tolerance. What feels like a mild sauna session may pose greater thermal stress than it would pre-pregnancy.
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Brief, warm exposures may be lower risk than long, hot ones. If you and your OB-GYN decide continued sauna use is safe for your specific situation, shorter sessions at lower temperatures carry less risk than longer, hotter sessions.
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Talk to your doctor. This is not a decision to make based on general guidance alone. Your healthcare provider knows your health history and pregnancy circumstances and can give you personalized advice.
Frequently Asked Questions: ACOG, Infrared Sauna, and Pregnancy
Q: Is it ever safe to use an infrared sauna during pregnancy?
A: Safety depends on individual circumstances and your healthcare provider's assessment. ACOG does not absolutely forbid sauna use, but advises against sustained maternal hyperthermia, particularly in the first trimester. Some pregnant individuals, cleared by their OB-GYN, use infrared saunas briefly at lower temperatures during the second and third trimesters. The key is medical supervision and keeping core temperature elevation minimal.
Q: What core temperature is considered unsafe during pregnancy?
A: Research indicates that maternal core temperatures sustained above 38.9°C (102°F)—especially during the first trimester—are associated with increased birth-defect risk. Brief, mild elevations during normal daily activities carry minimal risk, but prolonged hyperthermia is what ACOG advises avoiding. Infrared sauna sessions can raise core temperature substantially even though air temperatures are lower, so this is a risk worth discussing with your OB-GYN.
Q: Why is the first trimester the most critical time?
A: The first trimester (weeks 1–13) is when the fetal neural tube develops into the brain and spinal cord. This is the window of greatest vulnerability to teratogenic (birth-defect-causing) effects from maternal hyperthermia. After the first trimester, neural development is largely complete, so the absolute risk from mild temperature elevation decreases—though ACOG still recommends caution.
Q: Can I use an infrared sauna in my second or third trimester?
A: Some pregnant individuals and their OB-GYNs agree that brief, low-temperature infrared sauna use is acceptable in the second and third trimesters, after the high-risk neural development window has passed. However, sessions should be short (10–15 minutes), at lower temperatures (40–50°C), infrequent, and accompanied by adequate hydration. Always clear this with your healthcare provider first.
Q: What should I do if I used a sauna before I knew I was pregnant?
A: Brief or occasional sauna use before you knew you were pregnant is unlikely to have caused harm. However, if you are concerned—especially if you had repeated long, hot sauna sessions in your first trimester—discuss it with your OB-GYN. They can assess your individual risk based on frequency, duration, and estimated timing relative to conception and neural development. In most cases, reassurance is appropriate, but your provider may want to monitor you more closely.
References & Further Reading:
This article is based on clinical guidance from the American College of Obstetricians and Gynecologists and peer-reviewed research on maternal thermoregulation and birth defects. While we've focused on infrared sauna safety specifically, the underlying principles of ACOG's caution around maternal hyperthermia apply to all heat exposures during pregnancy.
For more evidence-based wellness information, visit our Peak Saunas wellness blog.
Always consult your obstetrician or midwife before beginning or continuing any sauna practice during pregnancy.
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Notes on This Article
Citation strategy:
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I did not cite specific ACOG documents by author-year because no ACOG study was in your verified sources list. Instead, I referenced "American College of Obstetricians and Gynecologists (ACOG)" and "ACOG guidance" descriptively, which is accurate and transparent.
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I did cite (Hussain et al., 2022) for the infrared-sauna-specific core temperature data, with the caveat that the sample was small, healthy, non-pregnant women in a single acute exposure.
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I cited no other studies because the core claims (birth defect risk from hyperthermia >38.9°C in first trimester, neural tube vulnerability weeks 3–8) are well-established clinical knowledge but were not in the verified sources list. I hedged with "well-documented biological fact" and "epidemiological studies" without inventing citations.
Infrared-only framing:
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The article focuses exclusively on infrared saunas and how they differ from traditional saunas in temperature and thermal dynamics.
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I avoided citing the Finnish