Placental abruption is an uncommon condition that can cause serious bleeding during pregnancy.
Table of Contents
- What are the symptoms of placental abruption?
- How is placental abruption diagnosed?
- How is placental abruption treated?
- Mild placental abruption
- Moderate or severe placental abruption
- What causes placental abruption?
- If I’ve had a placental abruption before, what are my chances of having it again?
- How can you reduce your risk for abruption?
If you experience placental abruption, it can cause problems for your baby, including growth issues, preterm birth or stillbirth.
If you have bleeding from your vagina while you’re pregnant, get help from your provider immediately or go to the hospital for evaluation.
If the bleeding is severe, it could be an abruption and your provider may recommend that you give birth right away.
The placenta attaches to the wall of the uterus [womb] and supplies the baby with food and oxygen through the umbilical cord.
Placental abruption is a serious condition in which the placenta separates from the wall of the uterus before birth. It can separate partially or completely. If this happens, your baby may not get enough oxygen and nutrients in the womb. You also may have pain and serious bleeding.
Normally, the placenta grows onto the upper part of the uterus and stays there until your baby is born. During the last stage of labor, after the baby is born, the placenta separates from the uterus, and your contractions help push it into the vagina [birth canal]. This is also called the afterbirth.
About 1 in 100 pregnant people [1 percent] have placental abruption. It usually happens in the third trimester but it can happen any time after 20 weeks of pregnancy. Mild cases may cause few problems. An abruption is mild if only a very small part of the placenta separates from the uterus wall. A mild abruption usually isn’t dangerous but needs to be followed closely because it can lead to complete separation.
If you have a placental abruption [greater separation between the placenta and the uterus], your baby is at higher risk for:
- Growth problems, called intrauterine growth restriction; identified by ultrasound
- Preterm birth [birth that happens too early, before 37 weeks of pregnancy]. An early delivery can be done to save you and your baby
- Stillbirth [when a baby dies in the womb after 20 weeks of pregnancy] if the separation of the placenta is sudden and severe.
Placental abruption is related to about 1 in 10 premature births [10 percent]. Premature babies [born before 37 weeks of pregnancy] are more likely than babies born later to have health problems during the first weeks of life, lasting disabilities, and even death.
Placental abruption can cause anemia and life threatening complications for a pregnant person. If it’s not diagnosed and treated immediately there can be hemorrhage and blood clotting complications for both, the baby and the pregnant person. Delivery by cesarean birth [c- section] section may be required.
What are the symptoms of placental abruption?
The main symptom of placental abruption is vaginal bleeding. You also may have pain,contractions, discomfort and tenderness or sudden, ongoing belly or back pain. Sometimes, these symptoms may happen without vaginal bleeding because the blood is trapped behind the placenta. If you have any of these symptoms, call your health care provider and go to the hospital right away.
How is placental abruption diagnosed?
If your provider thinks you are having an abruption, you may need to get checked at the hospital. Your provider can look for abruption by doing a physical exam and an ultrasound. An ultrasound can find many, but not all, abruptions. Your provider will also monitor your baby’s heartbeat.
How is placental abruption treated?
Treatment depends on how serious the abruption is and how far along you are in your pregnancy.
Your provider may simply monitor you and your baby. But sometimes you may need to give birth right away.
If you need to give birth right away and if there is time, your provider may give you medicines called corticosteroids. These medicines help speed up the development of your baby’s lungs and other organs.
Mild placental abruption
If you have a mild abruption at 24 to 34 weeks of pregnancy, you need careful monitoring in the hospital. If tests show that you and your baby are doing well, your provider may give you treatment to try to keep you pregnant for as long as possible. Your provider may want you to stay in the hospital until you give birth. If the bleeding stops, you may be able to go home.
If you have a mild abruption at or near full term, your provider may recommend inducing labor or c- section. You may need to give birth right away if:
- The abruption gets worse and you are having increased pain.
- You are bleeding heavily or show signs in your blood tests of severe anemia.
- Your baby has heart rate changes that indicate it is having problems.
Moderate or severe placental abruption
If you have a moderate to severe abruption, you are in a medical emergency.and usually need to give birth right away. Needing to give birth quickly may increase your chances of having a c-section.
If you lose a lot of blood due to the abruption, you may need a blood transfusion. An emergency c- section may be needed to save you and your baby. It’s very rare, but if you have heavy bleeding that can’t be controlled, you may need to have your uterus removed by surgery [hysterectomy]. A hysterectomy can prevent deadly bleeding and other problems in your body. But it also means that you can’t get pregnant again in the future.
What causes placental abruption?
We don’t really know what causes placental abruption. You may be at higher risk for placental abruption if:
- You had an abruption in a previous pregnancy.
- You have high blood pressure.
- You smoke cigarettes.
- You use cocaine.
- Your belly is harmed from a car accident or physical abuse.
- You’re a person who is 35 or older.
- You have an infection in your uterus.
- You are in preterm labor.
- Your water breaks before 37 weeks.
- You have problems with the uterus or umbilical cord.
- You have more fluid around the baby than is normal.
- You’re pregnant with twins, triplets or more.
- You have asthma.
- You have a sibling who had placental abruption.
- You’ve had a cesarean section in a previous pregnancy.
- You’ve been exposed to air pollution.
- Your sonogram shows evidence of mild separation of the placenta
If I’ve had a placental abruption before, what are my chances of having it again?
If you’ve had a placental abruption in a past pregnancy, you have about a 1 in 10 [10 percent] chance of it happening again in a later pregnancy.
How can you reduce your risk for abruption?
In most cases, you can’t prevent abruption. But you may be able to reduce your risk by getting closely monitored and treated for high blood pressure, not smoking or using street drugs, and always wearing a seatbelt when riding in a car. Your health care provider may also recommend that you take prenatal vitamins, including folic acid.
Last reviewed: September 2021
Bleeding may occur at various times in pregnancy. Although bleeding is alarming, it may or may not be a serious complication. The time of bleeding in the pregnancy, the amount, and whether or not there is pain may vary depending on the cause.
Miscarriage [pregnancy loss]
Ectopic pregnancy [pregnancy in the fallopian tube]
Gestational trophoblastic disease [a rare condition that may be cancerous in which a grape-like mass of fetal and placental tissues develops]
Implantation of the placenta in the uterus
Infection
Bleeding between the uterine wall and placental membrane [subchorionic hemorrhage or hematoma]
Normal changes in the cells of the cervix due to pregnancy
Placenta previa [placenta is near or covers the cervical opening]
Placental abruption [placenta detaches prematurely from the uterus]
Unknown cause
Placenta previa is a condition in which the placenta is attached close to or covering the cervix [opening of the uterus]. Placenta previa occurs in about one in every 200 live births. There are three types of placenta previa:
Total placenta previa. The placenta completely covers the cervix.
Partial placenta previa. The placenta is partially over the cervix.
Marginal placenta previa. The placenta is near the edge of the cervix.
The cause of placenta previa is unknown, but it is associated with certain conditions including the following:
Women who have scarring of the uterine wall from previous pregnancies
Women who have fibroids or other abnormalities of the uterus
Women who have had previous uterine surgeries or cesarean deliveries
Older mothers [over age 35]
African-American or other minority race mothers
Cigarette smoking
Placenta previa in a previous pregnancy
Being pregnant with a male fetus
The greatest risk of placenta previa is bleeding [or hemorrhage]. Bleeding often occurs as the lower part of the uterus thins during the third trimester of pregnancy in preparation for labor. This causes the area of the placenta over the cervix to bleed. The more of the placenta that covers the cervical os [the opening of the cervix], the greater the risk for bleeding. Other risks include the following:
Abnormal implantation of the placenta
Slowed fetal growth
Preterm birth
Birth defects
The most common symptom of placenta previa is vaginal bleeding that is bright red and not associated with abdominal tenderness or pain, especially in the third trimester of pregnancy. However, each woman may exhibit different symptoms of the condition or symptoms may resemble other conditions or medical problems. Always consult your doctor for a diagnosis.
In addition to a complete medical history and physical examination, an ultrasound [a test using sound waves to create a picture of internal structures] may be used to diagnose placenta previa. An ultrasound can show the location of the placenta and how much is covering the cervix. A vaginal ultrasound may be more accurate in diagnosis.
Although ultrasound may show a low-lying placenta in early pregnancy, only a few women will develop true placenta previa. It is common for the placenta to move upwards and away from the cervix as the uterus grows, called placental migration.
Specific treatment for placenta previa will be determined by your doctor based on:
Your pregnancy, overall health, and medical history
Extent of the condition
Your tolerance for specific medications, procedures, or therapies
Expectations for the course of the condition
Your opinion or preference
There is no treatment to change the position of the placenta. Once placenta previa is diagnosed, additional ultrasound examinations are often performed to track its location. Bed rest or hospital admission may be necessary. It may be necessary to deliver the baby, depending on the amount of bleeding, the gestational age, and condition of the fetus. Cesarean delivery is necessary for most cases of placenta previa. Severe blood loss may require a blood transfusion.
Placental abruption is the premature separation of a placenta from its implantation in the uterus. Within the placenta are many blood vessels that allow the transfer of nutrients to the fetus from the mother. If the placenta begins to detach during pregnancy, there is bleeding from these vessels. The larger the area that detaches, the greater the amount of bleeding. Placental abruption occurs about once in every 100 births. It is also called abruptio placenta.
Other than direct trauma to the uterus such as in a motor vehicle accident, the cause of placental abruption is unknown. It is, however, associated with certain conditions, including the following:
Previous pregnancy with placental abruption
Hypertension [high blood pressure]
Cigarette smoking
Multiple pregnancy
Sickle cell anemia
Placental abruption is dangerous because of the risk of uncontrolled bleeding [hemorrhage]. Although severe placental abruption is rare, other complications may include the following:
Hemorrhage and shock
Disseminated vascular coagulation [DIC]--a serious blood clotting complication.
Poor blood flow and damage to kidneys or brain
Stillbirth
Hemorrhage during labor
The most common symptom of placental abruption is dark red vaginal bleeding with pain during the third trimester of pregnancy. It also can occur during labor. However, each woman may experience symptoms differently. Some women may not have vaginal bleeding that is detectable, but there may be bleeding inside the uterus. Symptoms may include:
Vaginal bleeding
Abdominal pain
Uterine contractions that do not relax
Blood in amniotic fluid
Nausea
Thirst
Faint feeling
Decreased fetal movements
The symptoms of placental abruption may resemble other medical conditions. Always consult your doctor for a diagnosis.
The diagnosis of placental abruption is usually made by the symptoms, and the amount of bleeding and pain. Ultrasound may also be used to show the location of the bleeding and to check the fetus. There are three grades of placental abruption, including the following:
Grade 1. Small amount of vaginal bleeding and some uterine contractions, no signs of fetal distress or low blood pressure in the mother.
Grade 2. Mild to moderate amount of bleeding, uterine contractions, the fetal heart rate may shows signs of distress.
Grade 3. Moderate to severe bleeding or concealed [hidden] bleeding, uterine contractions that do not relax [called tetany], abdominal pain, low blood pressure, fetal death.
Sometimes placental abruption is not diagnosed until after delivery, when an area of clotted blood is found behind the placenta.
Specific treatment for placental abruption will be determined by your doctor based on:
Your pregnancy, overall health, and medical history
Extent of the disease
Tolerance for specific medications, procedures, or therapies
Expectations for the course of the disease
Your opinion or preference
There is no treatment to stop placental abruption or reattach the placenta. Once placental abruption is diagnosed, a woman's care depends on the amount of bleeding, the gestational age, and condition of the fetus. Vaginal delivery may be possible if the fetus is tolerating labor. If placental abruption is affecting the fetus, then cesarean delivery may be necessary. Severe blood loss may require a blood transfusion.