Many of the high white blood cells during pregnancy are physiological.1. During pregnancy, compensatory changes occur in all systems of the female body. The changes in the blood system are very obvious. The white blood cell count starts to rise gradually in the early stages of pregnancy and reaches its peak at around 30-34 weeks of pregnancy. A properly elevated white blood cell count enhances the body’s resistance to disease in pregnant women and helps prevent the occurrence of infectious diseases such as colds during pregnancy and inflammation of the urinary system.2. An elevated white blood cell count during the physiological phase of pregnancy, with a white blood cell count of around (10.0-12.0)×10^9/L, is not accompanied by other obvious clinical symptoms. If the white blood cell count is significantly elevated during pregnancy with symptoms of fever, it may be caused by an inflammatory disease and should be treated as soon as possible after identifying the cause.