Can pregnant women use warm patches?
Pregnant women can generally use heat pads, but if the fetus is unstable or the woman has a history of miscarriage, it may not be advisable. The details are as follows:

If a pregnant woman is in good health, she can usually use heat pads. When feeling cold and needing warmth on areas such as the back or legs, she may appropriately use heat pads. However, she should choose products with moderate temperature and no irritants, ensuring the skin does not become overly hot. Heat pads should not be applied directly to the abdomen to avoid potential adverse effects on the fetus due to excessive heat.
During early pregnancy, when the fetus is relatively unstable, using heat pads—especially on the abdomen—may stimulate uterine contractions and increase the risk of miscarriage; therefore, their use may not be recommended. Pregnant women with a history of miscarriage or those approaching their due date should avoid using heat pads, as localized overheating could trigger uterine contractions and raise the risk of premature labor.
It is recommended that pregnant women maintain an appropriate body temperature by wearing warm clothing or using electric blankets. If any discomfort occurs, they should seek medical attention promptly and follow medical advice for treatment.