Fast heart rate in pregnancy may be caused by changes in the blood and circulatory system, excessive activity, iron deficiency anemia, etc., and should be targeted to take general treatment, drug treatment. 1. Changes in the blood and circulatory system: the blood volume increases in pregnancy to adapt to the increased blood flow to the uterus, placenta and various tissues and organs, which is a protective mechanism against bleeding during pregnancy and childbirth. And the heart volume at the end of pregnancy can increase about 10%, and the heart rate increases by 10-15 beats per minute at rest. If there are no other discomforts, usually no special treatment is needed, and it can return to normal after delivery. 2. Excessive activity: It may be due to the physiological heart rate acceleration caused by excessive activity after pregnancy, pay attention to appropriate rest, the symptoms will gradually be relieved, usually pay attention to not overwork. 3. Iron deficiency anemia: generally have fatigue, irritability, palpitations, shortness of breath, dizziness, headache and other symptoms, if the pregnant woman has a serious iron deficiency anemia is also easy to lead to rapid heart rate, diet to increase nutrition, eat more iron rich food, such as pork, animal liver, etc., and at the same time, appropriate supplementation of iron supplements, such as ferrous sulfate, ferrous succinate. If the symptoms of fast heart rate in pregnancy continue to be unrelieved, you should go to the hospital in time to find out the cause.