There are two types of hemolysis in pregnant women, including ABO hemolysis and Rh hemolysis, and the main test for Rh hemolysis is done during the maternity checkup. Because if the pregnant woman is Rh negative and her husband is Rh positive, the anti-D potency needs to be rechecked every 2-4 weeks during the maternity checkup. If the anti-D potency is elevated, the baby is already sensitized and there is a possibility that the baby will develop edema and hemolysis; if the anti-D potency is normal, it is necessary to inject Rh immunoglobulin intramuscularly at 28 weeks and 72 hours after delivery; ABO hemolysis is not checked at present, but in the past, if the pregnant woman has type O blood and the husband is type A, B or AB, it is necessary to check the anti-A and anti-B potency. However, the antibodies were found to be elevated during pregnancy and the baby did not develop jaundice. Therefore, this test is not very accurate, so there are no anti-A and anti-B potency tests during pregnancy.