Pregnant women who feel cold are caused by insufficient heat production in the organism itself, weakness or due to relatively low temperature in the external environment. I. Iron deficiency anemia, women do not adjust their diet in time during pregnancy, resulting in insufficient intake of iron, causing obvious iron deficiency anemia, the resistance of pregnant women to cold is reduced, there will be symptoms of feeling cold. Second, fever, during pregnancy, if a pregnant woman has a fever due to a cold or other diseases, in the process of rising body temperature, the pregnant woman will also feel obvious chills, and may be accompanied by headache, general muscle pain, physical drowsiness, weakness and other symptoms. Third, physiological reactions, the appearance of such symptoms in the first trimester of pregnancy is considered a physiological reaction, which is related to the mild increase in physiological body temperature of pregnant women.