National Institutes of Health recommends that pregnant women
limit sauna use for the duration of their pregnancy. Increasing
body temperature above 100 degrees can increase the risk of fetal
complications or birth defects.
Pregnancy is no good time to remain inactive and sedentary. In fact, pregnant women benefit greatly and in many ways from engaging in physical activity.
Hot tubs can be very relaxing to pregnant women, and they are safe as long as the water does not heat up your body too much.
Can my husband use a sauna while we try to conceive (TTC)?
There are many studies both in animals and humans which show that hyperthermia, the abnormal elevation of body temperature, can adversely effect fetal development.
Heating up the testes may decrease the sperm count. Going into a sauna can heat up the body and the testes and have a negative effect on the sperm even many weeks later.