Suggested Limits to the Use of the Hot Tub and Sauna by Pregnant Women

Abstract

Abstract Because of reports of the potential risk of maternal hyperthermia to a developing embryo or fetus, studies were done to determine the length of time a woman must stay in a hot tub or sauna before her temperature reaches 38.9°C. The vaginal temperatures of 20 nonpregnant women of childbearing age were recorded while they sat in hot tubs set at 39.0°C or 41.1°C and in a sauna with an average temperature of 81.4°C. Five women were able to remain in the 39.0°C tub and six in the 41.1°C tub until their temperature reached 38.9°C, but in none did their temperature reach that level before 15 minutes in the 39.0°C tub or 10 minutes in the 41.1°C tub. The remainder left in discomfort while their body temperatures were lower. This indicates that the usual use of hot tubs is unlikely to raise a woman's body temperature to potentially teratogenic levels, although prolonged use may. None of the women were able to remain in the sauna long enough for their temperature to reach 39.9°C.