Puerperal infection is an inflammation caused by infection of reproductive organs during the puerperium. Pathogenic bacteria may invade from the outside world before, during or around delivery, or they may have already existed in the mother's body. However, whether or not puerperal infection occurs depends mainly on the local and systemic defense capabilities of the mother. Women who have anemia, malnutrition, pregnancy-induced hypertension syndrome or other diseases; women who do not have enough nutrition and water during delivery, have prolonged labor, and lose too much blood during and after delivery are prone to puerperal infection due to weakened systemic resistance. Women with premature rupture of membranes, prenatal bleeding, birth canal lacerations, and retained placentas are also prone to puerperal infection because local changes in the reproductive tract are conducive to the invasion and reproduction of bacteria.