If there are no clinical signs or symptoms of any infection, there is no reason to alarm. The increase in white blood cell count is typical in pregnancy. This count can vary from 5,000 leukocytes to 12,000 leukocytes per ml throughout the gestation, increasing at the end. During labor and shortly thereafter, it can exceed 25,000 per ml without any harm to the mother. We do not know exactly the cause, but some studies associate the event with greater maternal physical exhaustion, as occurs after rigorous physical exercise.
Wladimir Taborda is a gynecologist, obstetrician (CRM 54456) and doctor from the Federal University of São Paulo. He is the author of The Bible of Pregnancy and every month takes his doubts about pregnancy.