In a normal pregnancy, the placenta detaches itself from the wall of the uterus during the third stage of labor, after your baby is born.
Its function is now complete and it’s no longer needed to nourish your baby. Contractions continue to tighten and shrink the uterus after the birth, which causes the placenta to separate from the uterus and drop down into the birth canal to be expelled naturally.
What is placental abruption?
Placental abruption is a rare but serious complication of pregnancy that can cause severe complications for both the mother and her baby.
Placental abruption occurs when the placenta detaches from the wall of the uterus too early, before the baby is born. This can occur during pregnancy or during labor.
It can severely impair the supply of oxygen and nutrients to your unborn baby, leading to poor perinatal outcomes and possibly to severe bleeding in the mother.
Related reading: Placental Abruption | 13 Facts You Need To Know.
How common is placental abruption?
Placental abruption is an uncommon complication of pregnancy, affecting 1 in 100 (1%) singleton pregnancies. Abruption is most likely to occur in the third trimester but can occur at any point after 20 weeks gestation.
You are at higher risk of placental abruption in a future pregnancy if you’ve had a previous abruption.
Placental abruption risk factors
What causes placental abruption is still unclear; the risk of placental abruption, however, is increased by a number of factors, including:
- Placental abruption in a prior pregnancy. The recurrence rate is approximately 1 in 10 (10%)
- High blood pressure in pregnancy. Conditions such as pre-eclampsia increase the chance of abruption
- Abdominal trauma, caused by a fall, car accident, or violence
- Smoking and substance abuse
- Advanced maternal age (greater than 35)
- Infection of the uterus, known as chorioamnionitis
- Preterm labor or rupture of membranes (before 37 weeks)
- Polyhydramnios (too much amniotic fluid)
- Twins or triplets. Studies suggest that the incidence of abruption can double during multiple pregnancies
- Folic acid deficiency.
Placental abruption – signs and symptoms
The symptoms of placental abruption will vary, depending on its severity. However, there are some common ones to look out for, and things your healthcare provider will assess.
Some common signs and symptoms of placental abruption are:
- Heavy bleeding. The sudden onset of fresh dark red vaginal bleeding
- Abdominal pain. Tenderness to touch, or continuous pain
- Back pain. An aching sensation, or pain, might be referred into the back
- Rigid uterus. The uterus will feel firm to palpate
- Uterine contractions. Pain in between contractions, or contractions that feel they are coming on top of each other
- Signs of maternal shock, caused by serious bleeding: feeling cold, clammy, confused, anxious, or agitated; pale, with rapid breathing
- Fetal distress. Abruption can severely deprive the baby of essential oxygen, which will result in changes in heart rate patterns.
Women who experience placental abruption might notice any number of these symptoms. Although vaginal bleeding is the most common sign of placental abruption, not all abruptions will result in visible bleeding.
Placental abruption types
The amount of bleeding can differ greatly from person to person. The amount of bleeding that’s seen cannot be used to estimate the severity of the abruption, as some abruptions can occur with minimal or no visible blood loss.
An abruption can be classed as being either a mild or a severe placental abruption.
The severity of the abruption will depend on how far into your pregnancy you are, the symptoms presented, and how much of the placenta has come away.
Placental abruptions can be either complete or partial.
Complete separation means the entire placenta detaches from the uterus wall prior to the birth of the baby. Partial separation is when only part of the placenta comes away.
An abruption is referred to as concealed when the lower edge of the placenta remains intact but the separation occurs above. This causes blood to pool behind the placenta, creating clots.
During a concealed abruption, bleeding is not seen vaginally.
This can be the most dangerous type of placental abruption. The amount of blood loss can be greatly underestimated, as it is not seen vaginally; however, the mother can present with signs and symptoms of severe blood loss.
A revealed abruption occurs when the lower edge of the placenta separates and, instead of pooling, blood will be seen vaginally.
Vaginal bleeding in pregnancy
It’s important to remember that there can be a number of reasons why pregnant women experience vaginal bleeding during pregnancy. Not all vaginal bleeding will be caused by placental abruption. Other causes of bleeding include placenta previa or vasa previa.
However, if you experience any bleeding during your pregnancy, it’s important to contact your midwife or doctor straight away, so that the cause of bleeding can be investigated.
To learn more about placenta previa, read our article Placenta Previa | Symptoms And Bleeding.
How is placental abruption diagnosed?
Any vaginal bleeding during the second or third trimester requires urgent medical attention. Report any blood loss to your healthcare provider straight away. It’s likely you will need to be assessed to check on your well-being and your baby’s.
Because not all vaginal bleeding signifies placental abruption, investigations will be required to figure out the cause.
In the case of a suspected placental abruption, your care provider will perform a physical examination. This is likely to include a speculum examination, blood tests, and a monitoring of your baby’s heart rate.
You might also be offered an ultrasound, to see if the site of the bleeding can be determined.
Can placental abruption be seen on ultrasound?
Some but not all placental abruptions can be seen on ultrasound.
How serious is placental abruption?
A placental abruption can be extremely serious for the mother and her baby. It is classed as an obstetric emergency. If left untreated, placenta abruption can lead to:
- Anaemia and blood transfusion
- Organ failure
- Maternal death
- Fetal death or stillbirth.
An abruption can be categorized as either mild or severe. Naturally, a severe placental abruption will cause more concern than a mild one. Both, however, require urgent medical attention to assess the well-being of the mother and her baby.
If the bleeding is severe, sometimes it is necessary for the baby to be born right away, to prevent life-threatening complications.
Placental abruption increases the risk of:
- Growth problems. You might be offered extra scans to monitor your baby’s growth and amniotic fluid levels throughout the rest of your pregnancy
- Preterm birth. An early birth might be necessary to save your life and your baby’s
- Stillbirth. Sudden onset serious bleeding can quickly compromise the oxygen supply to your baby and, in rare cases, can lead to stillbirth.
How is placental abruption treated?
A placental abruption cannot be reversed or fixed but the condition can be managed carefully. Treatment depends on the number of weeks of pregnancy you’re at when the abruption occurs and the severity of the bleeding. It’s likely your doctor will advise you to be admitted to hospital for observation, assessment, and care planning for the safety of both you and your baby.
A mild placental abruption occurs if only part of the placenta detaches from the wall of the uterus.
If your healthcare provider concludes that both you and your baby are well and the bleeding has stopped, you might be able to go home. But you’ll probably need some extra follow-up and growth scans throughout the rest of your pregnancy to ensure your baby is growing well.
You might be given some medication to help your baby’s lung development, in case she needs to be born early. Premature babies (those born before 37 completed weeks of pregnancy) can have difficulties breathing and, sadly, some will not survive. Research confirms that steroid injections for the mother reduce the risk of serious lung disease and death in neonates.
Premature babies generally have more health problems than babies born at full term. These include breathing difficulties, low birth weight, seizures, and other complications. The goal will be to prolong your pregnancy for as long as possible, while keeping you and your baby safe.
Related reading: Premature Babies – What To Expect Week By Week.
Can I still have a vaginal birth after a placental abruption?
If the placenta separates completely from the uterine wall, or if bleeding is severe, it might be necessary for your baby to be born right away, by cesarean, to prevent further pregnancy complications.
Giving birth to your baby vaginally, however, shouldn’t be completely ruled out if you have a placental abruption. It might still be possible to give birth vaginally, while being closely monitored, if the bleeding has stopped and you and your baby are stable.
Discuss with your doctor what the best options are for you and your baby.
Can a baby survive a placental abruption?
Placental abruption can have catastrophic effects, with around 15% of severe placental abruptions ending in fetal death.
If you’ve been treated for suspected placental abruption or have had bleeding in pregnancy, this can feel frightening. This is why it’s important to seek urgent medical attention if you do experience any bleeding.
How can I prevent placental abruption?
Placental abruption cannot be completely prevented; however, you can reduce the chances of it occurring by keeping yourself as healthy as possible. Some things you can do:
- Attend your regular checkups
- Monitor and treat any pre-existing conditions, or blood pressure problems in pregnancy
- Avoid smoking and illicit drugs during pregnancy
- Always use a seat belt when traveling
- Report any bleeding or reduced fetal movement
- Seek support if you are experiencing any form of domestic violence or abuse.