Defined as the loss of more than 1 liter of blood in the first 24 hours after giving birth accompanied with signs of low blood volume (such as passing out or low blood pressure), postpartum hemorrhage (PPH) is the deadliest complication of childbirth worldwide, with one woman dying because of it every 4 minutes. Even though a woman’s blood volume increases by 40 percent during her pregnancy, an excessive hemorrhage can still be life-threatening.
PPH may be primary (occurring within the first 24 hours after delivery) or secondary (occuring from 24 hours to 6-12 weeks postpartum). Primary PPH occurs in about 4-8 percent of all deliveries. The great majority of the time (about 80 percent) this happens because of something called uterine atony. This is when the uterus does not contract after the baby and placenta are delivered, resulting in blood vessels remaining open and left to bleed very briskly. Risk factors for uterine atony include an infection in the uterus, prolonged labor, having delivered a large or multiple babies, or having had an excessive amount of amniotic fluid.
While uterine atony is a common cause in primary PPH, other problems can also cause it. These include when a piece of the placenta is stuck in the uterus (called retained placenta), when the uterus turns inside out (called uterine inversion), from extensive vaginal or cervical lacerations, or when the mother has another medical problem that makes it difficult for her blood to clot (such as in HELLP syndrome).
Secondary PPH can also be caused by some of the issues already mentioned. In addition, when the site that the placenta attached to involutes (usually around 10-14 days postpartum) there can be heavy bleeding that could lead to secondary PPH. A uterine infection that developed after delivery, as well as early sexual activity, could also lead to secondary PPH.
Once PPH has been diagnosed, your obstetric provider will need to determine the cause of it. The treatments depend on why you are bleeding in the first place, and they may include some combination of the following:
- Medication to help your uterus contract (given orally, rectally, as an injection, or in your IV).
- Massage of your uterus to help it contract.
- Removal of placental fragments, either by hand or via a surgical procedure called a dilation and curettage (D&C).
- Placement of packing or gauze in the uterus to hold pressure.
- Administration of IV fluids and possibly a blood transfusion.
- Surgery to repair any lacerations or to decrease blood flow to the uterus.
- Embolization (or clotting off) of the uterine vessels done by an interventional radiologist.
While a postpartum hemorrhage can be a very frightening complication of childbirth, the good news is that obstetric teams prepare for this with detailed protocols, simulations, and debriefings of recent scenarios. Thankfully, in the United States the majority of women who experience this do very well, but unfortunately the same cannot be said of many women worldwide.
Reviewed by Jennifer Lincoln, January 2019
- Postpartum hemorrhage is the loss of more than 500 mL of blood after a vaginal delivery or 1 liter of blood after a C-section.
- It is the deadliest complication of childbirth, with a woman dying from it every 4 minutes.
- The most common cause of postpartum hemorrhage is uterine atony.