Placenta Abruptio

What is placenta abruptio?

Normally during pregnancy, the placenta is firmly attached to the inner wall of the uterus until the baby has been born. Placenta abruptio is the premature separation (abruption) of the placenta before childbirth. Since the round, flat placenta is a "lifeline" that supplies nutrients and oxygen to a fetus from the mother, an abruption can be life-threatening for the fetus, and sometimes for the mother as well. Placenta abruptio can lead to preterm birth, low birth weight [at or below 2500 g (5.51 lb)], and major maternal blood loss. In rare cases, severe placenta abruptio leads to fetal or newborn death.¹

See an illustration of placenta abruptio .

Placenta abruptio, also referred to as abruptio placenta or placental abruption, affects about 9 in 1,000 pregnancies.² It usually occurs in the third trimester of pregnancy, but it can occur any time after the 20th week. Up to 15 of every 100 abruptions aren't obvious until labor is in progress or after delivery.³

What causes placenta abruptio?

The causes of placenta abruptio are not well-understood, and some women develop it without any identifiable cause. However, you can reduce your risk by treating or avoiding some of the known risk factors that have been linked to placenta abruptio.

Common risk factors for placenta abruptio include:

• High blood pressure (140/90 mm Hg or higher), whether it is chronic or has been caused by the pregnancy (pregnancy-induced hypertension or preeclampsia). High blood pressure is the most common risk factor linked to placenta abruptio.⁴
• A past placental abruption. If you have had more than one abruption, your risk is greater.²
• Cigarette smoking. The more you smoke, the greater your risk of abruption. Up to 25 of every 100 placental abruptions are linked to cigarette smoking.⁵

Other risk factors for placenta abruptio include cocaine use; having a surgical scar or uterine fibroid where the placenta has attached; trauma to the uterus, as might occur in a car accident; and premature rupture of membranes for 24 hours or more, especially when there is an infection in the uterus.

What are common symptoms of placenta abruptio?

If you have developed placenta abruptio, you may notice one or more symptoms, including:

• Vaginal bleeding that is light or heavy, dark or bright red, depending on the location of the abruption and how long it's taken for the blood to pass.
• A tender, painful, or hard, rigid-feeling uterus.
• Signs of preterm labor, including regular contractions, lower back or abdominal ache or pain.

The amount of vaginal bleeding isn't a good measure of how severe an abruption is—heavy bleeding is sometimes the least apparent because the blood can remain trapped between the placenta and uterine wall. Heavy blood loss can cause symptoms of shock, including lightheadedness, weakness, confusion, restlessness, and shallow, rapid breathing.

How is placenta abruptio diagnosed?

Your health professional may suspect placenta abruptio based on your symptoms, fetal heart rate pattern, an ultrasound, and possibly a blood test to check whether you're anemic from losing blood.

If you are suspected to have a placental abruption, you'll be observed for at least a few hours in the hospital. Your health professionals will need to assess how severe the abruption is, whether it is worsening, and whether it is affecting your fetus.

How is it treated?

Treatment depends on how severe the abruption is, how it is affecting your fetus, and how close your due date is. A mild abruption may resolve and can often be closely observed on an outpatient basis for the remainder of a pregnancy. A moderate to severe abruption requires hospitalization and constant fetal monitoring, and usually results in delivery, sometimes by emergency cesarean.

Frequently Asked Questions

Not every woman with placenta abruptio has telltale symptoms.

If you have placenta abruptio, you may notice one or more symptoms, including:

• Vaginal bleeding. Depending on the location and amount of separation, vaginal bleeding varies in amount (scant to heavy) and color (bright to dark red). Light vaginal bleeding does not necessarily indicate a minor problem; in some cases, a large amount of blood can be pooled between the placenta and the uterine wall, resulting in little or no vaginal bleeding.
• Uterine tenderness or pain. The uterus may feel hard or rigid.
• Signs of preterm labor. In some women with placenta abruptio, labor symptoms are the first sign of trouble. Labor symptoms can include:
  • Regular contractions.
  • Pain in the abdomen or back. This pain can be sharp or aching.

In rare cases, when heavy blood loss is retained in the uterus behind the placenta, the only signs of placenta abruptio are symptoms of shock. Early signs of shock (most of which are present at once) include:

• Lightheadedness or a feeling that you are about to pass out.
• Restlessness, confusion, or feelings of fear or anxiety.
• Shallow, rapid breathing.
• Moist, cool skin or possibly profuse sweating.
• Weakness.
• Thirst, nausea, or vomiting.

High blood pressure (hypertension) is the most common risk factor associated with placenta abruptio.⁴ For more information, see the topic Preeclampsia and High Blood Pressure During Pregnancy.

A separation of the placenta from the uterine wall, or placenta abruptio, can be difficult to identify. Diagnosis is based on a physical examination, a medical history, and a process of elimination. Testing may include:

• Fetal heart monitoring, to assess the fetus's condition and check for contractions of the uterus.
• An ultrasound test, which can detect about 50% of placental abruptions.⁶ A negative ultrasound result does not necessarily guarantee that the placenta is intact.
• A blood test for anemia. A woman with placenta abruptio can become anemic from excessive blood loss.

A placenta that has separated from the uterine wall (placenta abruptio) cannot be repaired. Until its severity can be assessed, placenta abruptio is considered a medical emergency. If you have suspected or diagnosed placenta abruptio, you will need to be observed in the hospital. Some abruptions can worsen quickly and become life-threatening for both you and your fetus.

If your blood type is Rh-negative and you have placenta abruptio, you will have a RhoGam shot. This is because your fetus could be Rh-positive. Bleeding from an abruptio can mix the Rh-positive blood with yours. The RhoGam prevents your immune system from attacking the Rh-positive blood.

Placenta abruptio is usually treated by an obstetrician or perinatologist.

Mild placenta abruptio

If placental separation is minor, vaginal bleeding is light, and your fetus is not in distress, you may be observed in the hospital for several hours or several days. For the remainder of your pregnancy, you'll probably be advised to avoid strenuous activities, and you and your fetus will need to be monitored regularly.

If you are in preterm labor, the separation is minor, and you are far from your due date, you may be given tocolytic medication to stop labor. For more information, see the topic Preterm Labor.

Moderate to severe placenta abruptio

If placental separation is moderate to severe, or if it causes a life-threatening condition called disseminated intravascular coagulation (DIC), rapid delivery is almost always necessary. Although vaginal delivery is sometimes possible, the need for rapid delivery increases the likelihood of a cesarean (C-section). In rare cases of heavy bleeding that won't stop, the uterus is surgically removed (hysterectomy).

Depending how much blood you have lost and whether you have disseminated intravascular coagulation, you may need a transfusion of blood or blood-clotting products, such as platelets.

How well your baby does after a placental abruption depends on how prematurely he or she is delivered and how well the placenta was able to circulate blood oxygen and nutrients to the fetus before delivery.

Following delivery, it may be necessary to remain close to a health center able to care for premature infants. A sick or premature newborn can receive the best treatment possible in a neonatal intensive care unit, or NICU. Care in the NICU can last days or weeks, depending on the baby's level of maturity, the extent of the baby's problems, and the amount of care needed. For more information, see the topic Premature Infant.

Treatment for premature infants can be provided by a neonatologist, a doctor who specializes in the care of newborns.

Future pregnancy

After having one placental abruption, you have an increased risk of developing another during a future pregnancy. After two or more, you have a 1-in-4 risk of having another.² Although there are no specific treatment guidelines for preventing another placental abruption, you and your health professional can take some steps to reduce your risk.

• Avoid high-risk factors such as drug use, cigarette smoking, or untreated high blood pressure (140/90 mm Hg or higher).
• Take prenatal vitamins with adequate folate [400 µg (0.4 mg)], since low folate has a possible link to placental problems and abruption.^{7, 6}
• See your health professional regularly throughout your pregnancy.

During pregnancy, pay attention to symptoms or injuries that can be related to the placenta separating from the uterine wall (placenta abruptio). Call your health professional immediately if you are pregnant and you experience:

• Any vaginal bleeding.
• Severe pain in your abdomen. The uterus may feel hard or rigid.
• A blow to the abdomen, as from a fall or a physical attack.
• A motor vehicle accident.
• Signs of preterm labor, including:
  • Regular contractions.
  • Pain in the abdomen or back. This pain can be sharp or aching.

Call 911 or other emergency services immediately if you have symptoms of shock (from heavy blood loss), including lightheadedness, weakness, confusion, restlessness, and shallow, rapid breathing.

Prevention

Although most cases of placenta abruptio cannot be directly prevented, you can avoid or treat factors that are known to greatly increase your risk of placental abruption.

• Avoid cigarette smoking during pregnancy.
• Avoid cocaine and methamphetamine use during pregnancy.
• Keep a regular schedule of prenatal checks throughout your pregnancy.
• If you have high blood pressure, carefully follow your health professional's treatment recommendations.
• Take prenatal vitamins with folate [400 µg (0.4 mg)], since low folate has a possible link to placental problems and abruption.^{7, 6}

Even during a healthy pregnancy, placenta abruptio is a possible complication. However, you can optimize your fetus's and your ability to handle a medical complication by making healthy lifestyle choices and having regular prenatal checks throughout your pregnancy. For more information, see the topic Pregnancy.

Coping with loss

Should your baby die as a result of placenta abruptio, allow yourself permission and time to grieve your loss. Your partner, children, and other family members may also need time to grieve.

Contacting a support group, reading about the experiences of other women, and talking to your doctor, friends, a counselor, or a member of the clergy may help you and your family deal with your loss. For more information, see the topic Grief and Grieving.

If you have plans to become pregnant after having had placenta abruptio, talk to your health professional ahead of time about maximizing your chances of a healthy pregnancy in the future.

Organizations

• Cesarean Section
• Grief and Grieving
• Preeclampsia and High Blood Pressure During Pregnancy
• Premature Infant
• Preterm Labor
• Quitting Tobacco Use

Citations

1. Clark SL (2004). Placenta previa and abruptio placentae. In RK Creasy, R Resnik, eds., Maternal-Fetal Medicine, 5th ed., pp. 707–722. Philadelphia: Saunders.

2. Miller DA (2002). Abruptio placentae. In DR Mishell Jr et al., eds., Management of Common Problems in Obstetrics and Gynecology, 4th ed., pp. 141–144. Malden, MA: Blackwell.

3. Claydon CS, Pernoll ML (2003). Third-trimester vaginal bleeding. In AH DeCherney, L Nathan, eds., Current Obstetric and Gynecologic Diagnosis and Treatment, 9th ed., pp. 354–368. New York: McGraw-Hill.

4. Cunningham FG, et al. (2001). Placenta abruption section of Obstetrical hemorrhage. In William's Obstetrics, 21st ed., pp. 621–630. New York: McGraw-Hill.

5. Ananth CV, et al. (1999). Incidence of placental abruption in relation to cigarette smoking and hypertensive disorders during pregnancy: A meta-analysis of observational studies. Obstetrics and Gynecology, 93(4): 622–628.

6. Kay HH (2003). Placenta previa and abruption. In JR Scott et al., eds., Danforth's Obstetrics and Gynecology, 9th ed., pp. 365–379. Philadelphia: Lippincott Williams and Wilkins.

7. Eskes TKAB (2001). Clotting disorders and placental abruption: Homocysteine—a new risk factor. European Journal of Obstetrics and Gynecology and Reproductive Biology, 95: 206–212.