Postpartum hemorrhage

Hemorrhage after delivery, or postpartum hemorrhage, is the loss of greater than 500 ml of blood following vaginal delivery, or 1000 ml of blood following cesarean section. It is the most common cause of perinatal maternal death in the developed world and is a major cause of maternal morbidity worldwide.

Causes
Causes of postpartum hemorrhage are uterine atony, trauma, retained placenta, and coagulopathy, commonly referred to as the "four Ts":
 * Tone: uterine atony is the inability of the uterus to contract and may lead to continuous bleeding. Retained placental tissue and infection may contribute to uterine atony.
 * Trauma: trauma from the delivery may tear tissue and vessels leading to significant postpartum bleeding.
 * Tissue: retention of tissue from the placenta or fetus may lead to bleeding.
 * Thrombin: a bleeding disorder occurs when there is a failure of clotting, such as with diseases known as coagulopathies.

Medication
Intravenous oxytocin is the drug of choice for postpartum hemorrhage. Misoprostol may also be effective if oxytocin is not available.

Protocol
A detailed stepwise management protocol has been introduced by the California Maternity Quality Care Collaborative. It describes 4 stages of obstetrical hemorrhage after a delivery and its application reduces maternal mortality.
 * Stage 0: normal - treated with fundal massage and oxytocin.
 * Stage 1: more than normal bleeding - establish large-bore intravenous access, assemble personnel, increase oxytocin, consider use of methergine, perform fundal massage, prepare 2 units of packed red cells.
 * Stage 2: bleeding continues - check coagulation status, assemble response team, move to operating room, place intrauterine balloon, administer additional uterotonics (misoprostol, carboprost tromethamine), consider: uterine artery embolization, dilatation and curettage, and laparotomy with uterine compression stitches or hysterectomy.
 * Stage 3: bleeding continues - activate massive transfusion protocol, mobilize additional personnel, recheck laboratory tests, perform laparotomy, consider hysterectomy.

A Cochrane review suggests that active management (use of uterotonic drugs, cord clamping and controlled cord traction) of the third stage of labour significantly reduces severe maternal bleeding and anemia compared to expectant management. However, the review also found that active management increased the mother's blood pressure, afterpains, nausea, vomiting, and use of drugs for pain relief. In the active management group more women returned to hospital with bleeding after discharge, and there was also a reduction in birthweight due to infants having a lower blood volume. Another Cochrane database study, focusing specifically on the timing of the administration of the uterotonic drug oxytocin as part of the active management of the third stage of labour, suggested that administering the drug before the expulsion of the placenta did not have any significant influence on the incidence of postpartum hemorrhage when compared to administering the drug after the expulsion of the placenta.