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What Is Placental Abruption?
The placenta is a round, flat organ that develops during pregnancy. It attaches to the inside of the uterus and provides the baby with nutrients and oxygen.
A placental abruption is when the placenta partially or completely separates from the wall of your uterus before the baby is born. The separation of a placental abruption cannot be fixed.
An abruption can cause dangerous bleeding and deprive your baby of oxygen and other nutrients. This increases the risk of stillbirth or preterm delivery. Placental abruption also can cause blood loss, placing the pregnant person in danger of shock.
Placental abruption also may be referred to as abruptio placentae.
Placental abruption can happen at any time after the 20th week of pregnancy. It most often occurs in the third trimester, often before 37 weeks. Relatively uncommon, it occurs in only 0.6% to 1.2% of all pregnancies in the U.S., according to a review in the American Journal of Obstetrics & Gynecology.
The rate of placental abruption appears to be increasing in some countries, though it is not known why. It is the cause of about 10% of all preterm births, according to the March of Dimes. It is also the cause of 10% to 20% of all perinatal (during delivery) deaths, according to a review in the journal Acta Obstetricia Et Gynecologica Scandinavica.
What are the types of placental abruption?
Placental abruption can be partial or complete.
- Partial separation — The placenta only detaches in a small area. In mild cases, your doctor will have you limit activity and monitor you closely. The more the placenta separates, the more serious the condition becomes.
- Complete separation — The placenta entirely separates from the uterus. In cases of full separation, they will need to deliver your baby immediately. If your baby is stable, you may be able to deliver vaginally. If not, they'll need to do an emergency C-section.
What causes placental abruption?
In a normal pregnancy, the placenta stays firmly attached to the inside wall of the uterus until after the baby is born. In some cases of placental abruption, a trauma, such as a fall or sharp blow to the abdomen, may cause the placenta to break away early. This could occur because of a car accident, a fall, or physical abuse.
But in other cases, doctors aren't sure what causes placental abruption. Certain pregnancy complications and health issues can put you at higher risk.
Placental abruption risk factors and complications
Placental abruption risk factors
Common risk factors for placental abruption include:
- Advanced maternal age, especially if you are older than 35.
- Blood clotting disorders.
- Having scarring or a uterine fibroid where the placenta attaches to the wall of the uterus.
- Having a sibling who has had placental abruption.
- Having asthma or having been exposed to air pollution.
- Having had placental abruption in a previous pregnancy.
- Having problems with your uterus or the umbilical cord or having an infection in your uterus.
- High blood pressure or preeclampsia (high blood pressure occurring after 20 weeks of pregnancy.)
- Using cocaine or crack.
- Pregnancies with multiples, such as twins or triplets.
- Having your water break or leak more than 24 hours before labor starts.
- Smoking during pregnancy.
Placental abruption complications
Placental abruption can be dangerous for you and your baby. In rare cases, it can be potentially life-threatening.
Other common complications due to placental abruption include:
- Blood loss — You may need a transfusion.
- Future C-section deliveries — If you have an emergency C-section, you may need C-sections for any subsequent deliveries.
- Hysterectomy — If you're bleeding too much, the doctors may take out your uterus.
- Low birth-weight baby — Baby may be small if they don't get enough nutrients.
- Maternal death – In the United States, placental abruption accounts for about 1% to 5% of maternal deaths, according to StatPerls. The maternal survival rate for placental abruption is between 95% and 99%.
- Neonatal death — The death of a baby in the first 28 days of life.
- Perinatal asphyxia — A lack of blood or oxygen flow to the baby during the birth process. This can harm the baby's brain.
- Perinatal death — The death of a baby during birth.
- Premature baby — Babies born before 37 weeks are premature.
- Recurrent placental abruption — Having an abruption in future pregnancies. The recurrence rate is 3% to 10%, according to Medscape.
- Stillbirth — Death of a baby before delivery.
Can a baby survive placental abruption?
Most babies survive placental abruption. The fetal mortality rate depends on the age of the fetus and the extent of the placental separation. About 15% of the most severe cases of placental abruption will end in fetal death, according to the American Pregnancy Association.
Can placental abruption be prevented?
There is no way to prevent placental abruption, but you can do things to lower your risk.
- Avoid contact sports and other activities that increase your risk of injury. Common causes of injury include basketball, soccer, skiing, and motorcycle riding while pregnant.
- Don't smoke while you're pregnant.
- Don't use drugs like cocaine and methamphetamine while pregnant.
- Get regular prenatal checkups throughout your pregnancy.
- If you have high blood pressure, follow your doctor's treatment advice.
- Wear your seat belt properly while riding in a car. Buckle the lap belt below your belly and across your hips, and place the shoulder belt across your chest, between the breasts, and away from your neck.
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What Are the Symptoms of Placental Abruption?
If you are pregnant and have placental abruption, you or your doctor may notice one or more warning signs:
- Bleeding can vary from light to moderate or be severe, such as a gush of blood or the passing of a clot.
- Increased fetal heart rate.
- Pain, including back pain and sudden or severe pain in your belly.
- Reduced fetal movement.
- Signs of early labor. These include regular contractions and aches or pains in your lower back or belly.
- Sore or hard uterus.
- Symptoms of shock, including feeling lightheaded or like you're going to faint, confused, restless, or weak, feeling sick to your stomach or vomiting, and having fast, shallow breathing.
How much and how often you're bleeding does not signal how severe the placental abruption is. About 20% of people with placental abruption experience no vaginal bleeding at all, according to the Birth Injury Help Center.
In these cases, the blood gets stuck between the placenta and the wall of the uterus. Even if there is a severe internal problem, there is only a little bleeding externally.
This is why it is critical that you alert your doctor right away if you have any of the symptoms above, especially vaginal bleeding of any sort, during the third trimester.
In rare cases, symptoms of shock may be the only signs of a serious problem.
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How Do You Diagnose Placental Abruption?
Placental abruption can be challenging to diagnose. Your doctor will ask questions about your symptoms, conduct a thorough physical exam, and run some tests.
Tests include:
- Electronic fetal monitoring — This is to assess your baby's condition and check for contractions of the uterus.
- Ultrasound — Doctors can't see most placental abruptions on an ultrasound.
- CT scan — Your doctor may do this if you have an injury to your belly.
If placental abruption is suspected, you'll probably need to be in the hospital until your doctor finds out how severe it is. A placental abruption can only be confirmed by looking at the placenta after birth.
Vaginal bleeding in the second half of pregnancy is often the result of either placental abruption or placenta previa. Placental abruption tends to result in a more sudden and intense onset of bleeding. Additionally, while the uterus is soft and relaxed in placenta previa, the uterus is firm and hard in placental abruption.
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How Do You Treat Placental Abruption?
Placental abruption requires immediate treatment. It tends to occur suddenly and intensely, sometimes without much warning.
Your doctor will consider several factors when determining treatment options, such as your condition, the amount of bleeding, your baby's heart rate, and your baby's gestational age.
Your treatment also may depend on how severe the abruption is, how it affects your baby, and how close your due date is. No treatment prevents the placenta from detaching, and there is no way to reattach it.
Your doctor may suggest:
- Bed rest — Limited activity to reduce bleeding and likelihood of further detachment.
- Blood transfusion — If you have lost a lot of blood, you may need a blood transfusion.
- Close monitoring – If your doctor considers it safe enough to continue with your pregnancy, you and your baby will be checked often, and you may be able to attempt a vaginal delivery.
- Corticosteroid medicine — If you're not at term, the doctors can give this medicine to speed up the development of your baby's lungs. This decreases the risk that your baby will have breathing difficulties.
- Emergency C-section — In some cases of placental abruption, your baby will need to be delivered quickly.
- Hospitalization — You may need to stay in the hospital until delivery if your condition worsens. If you have mild placental abruption and your baby is not in distress, you may not have to stay in the hospital.
- Hysterectomy — In cases of severe, uncontrollable bleeding, your doctor may need to remove your uterus after your baby is delivered using a procedure called a hysterectomy.
- Medicine to stop labor — If the abruption sent you into preterm labor but you are far from your due date, you may get medicine to stop labor.
- NICU — If your baby arrives premature, they may need a neonatal intensive care unit (NICU). The NICU cares for premature or ill newborns. You may be transferred to another hospital with an appropriate NICU if your baby is very premature.
By UPMC Editorial Staff. Last reviewed on 2024-09-05.
