Postpartum Hemorrhage

Postpartum haemorrhage (PPH) is excessive bleeding after birth that can become life-threatening before the measured volume appears dramatic. The classic definition is blood loss of more than 500 mL after vaginal birth or more than 1000 mL after caesarean birth within 24 hours. Since 2017 the American College of Obstetricians and Gynecologists (ACOG) has defined PPH as blood loss of at least 1000 mL, or blood loss with signs or symptoms of hypovolaemia, within 24 hours of birth regardless of the route of birth. Units differ in which convention their protocol uses, so learn your own unit's definition. WHO (2025) now sets a treatment trigger that begins earlier than either definition (see the next section). None of these numbers should delay treatment of an unstable patient. The mechanism is often failure of the uterus to contract. After the placenta separates, contraction compresses the open spiral arteries at the placental site. A relaxed, enlarged uterus leaves those vessels open, producing uterine atony—the commonest cause of PPH. The other principal causes are remembered as the four Ts: - Tone: a boggy or...