Get exclusive member benefits & effect social change. Join Today
After a woman gives birth and the umbilical cord has been cut, her body sends a signal to her uterus that the placenta is no longer needed. The placenta then begins to peel away from the uterine wall so that it can leave the body following the path the baby just took. Sometimes, the placenta begins to peel away from the uterus too soon, while the baby still needs the placenta to supply oxygen and nutrients. This is called placental abruption or just abruption.
Doctors aren't sure exactly how placental abruption occurs. Many believe, however, that tiny blood vessels on the surface of the placenta begin to leak and form a bruise or blood blister, which then spreads between the placenta and the uterine wall. The blood loosens the connection between the uterine wall and the placenta, allowing it to separate.
To decide on the type of abruption a woman has, doctors look for two things:
When a woman has placental abruption, the most common signs are:
If a woman is already in labor, abruption can increase the duration of contractions and cause her uterus to become and remain hard to the touch.
Placental abruption is often difficult to diagnose because only about 60 to 75% of women have signs-signs that often indicate other conditions, like placenta previa, uterine rupture, and labor. Placental abruption is diagnosed clinically by close observation. Ultrasounds and certain laboratory tests may be helpful, but most cases are diagnosed by painful uterine contractions and abnormalities in the baby's heartbeat. To rule out other causes of abdominal pain, vaginal bleeding, and contractions, a combination of ultrasound and close observation are used.
Even after a diagnosis has been confirmed, it may be difficult to determine just how much of the placenta has separated from the uterine wall. A woman with heavy vaginal bleeding, for example, may have only a small amount of separation, while a woman with no bleeding at all can have complete separation. (In these cases, the blood usually has been trapped inside the woman's body in the uterus.)
While doctors aren't sure what causes placental abruption, they are aware of some risk factors. Physical trauma to the stomach, for example, can pull the placenta off the uterine wall. Or, if too much fluid surrounds the baby ( polyhydramnios ), the mother's ?water? will break, causing her uterus to shrink rapidly from the loss of fluid. Because this change in size is so great, her body thinks the baby has been delivered and gives the placenta the signal to begin separating.
Factors that increase a woman's risk for abruption include:
Abruption is a common complication of pregnancy. About one in 20 women probably have small abruptions, but these are small enough they do not affect the mother or her baby. In fact, doctors rarely know that these abruptions exist. About one in 120 women who deliver has a larger abruption, and about one in 830 has an abruption so severe that the baby cannot survive.
Placental abruption is a serious condition that may result in maternal death. Fortunately, this risk is much lower today than it was in the past. In the early-1900s, about one out of 12 women with placental abruption died. Now, less than one woman in a 100 die, due to better surgical care, ways to make up for lost blood, antibiotics, and better hospital intensive care units (ICUs).
The main risks associated with placental abruption include:
There is another complication of placental abruption. Sometimes, the bleeding between the placenta and the uterus spreads to the surface of the uterus, making it look purplish or blue, like a bruise. This is called uteroplacental apoplexy (or sometimes Couvelaire uterus, after the doctor who first described it). Often, this type of uterus may not be able to contract as well and may need to be removed (hysterectomy) in order to control uterine bleeding.
The most significant risk to the baby is dying inside the womb. The chances of this happening depend on:
Written by: Rachel Nall, RN, BSN, CCRN
Published on: Mar 15, 2012
Medically reviewed on: Dec 23, 2015: Janine Kelbach, RNC-OB
Enter your symptoms in our Symptom Checker to find out possible causes of your symptoms. Go.
Enter any list of prescription drugs and see how they interact with each other and with other substances. Go.
Enter its color and shape information, and this tool helps you identify it. Go.
Find information on drug interactions, side effects, and more. Go.
From companies that meet the high standards of service and quality set by AARP.
Members save 10% on the monthly service charge of qualified AT&T wireless plans.
Members pay $9.50 for Regal ePremiere Tickets purchased online.
Members earn points on select Walgreens-brand health and wellness products.
Join or renew today! Members receive exclusive member benefits & affect social change.