Pregnant women sweat while sleeping, mainly due to increased metabolism, similar to pregnancy vomiting, changes in diet, etc., which is a normal physiological phenomenon during pregnancy. When pregnant, the secretion of estrogen and progesterone increases, the adrenal cortical function is in a state of excitement for a long time, and with the growth and development of the fetus, the basal metabolic rate of pregnant women increases more than usual, plus the function of the vegetative nervous system changes, the blood flow in the skin increases, and the body temperature is higher than when not pregnant. If a pregnant woman sleeps under a thick blanket or wears clothing that is not well ventilated, she will sweat, depending on her body type. In late pregnancy, sweaty eczema may also occur, and some pregnant women may continue to have sweaty sleep until after delivery. In addition, we cannot exclude that some pregnant women have sweating due to anemia, calcium deficiency, and other reasons. In case of calcium deficiency, it may be accompanied by limb cramps and should be treated early.