What is placental abruption, and can it injure the baby?

The placenta is a sac-like structure within the uterus (womb) where the baby develops during pregnancy. It contains a network of blood vessels that supply nutrients and oxygen to the baby through the umbilical cord. The baby ‘breathes’ through the umbilical cord, where a vein delivers oxygenated blood to the baby, and an artery passes deoxygenated blood back to the mother to pick up more oxygen. Anything that prevents the placenta and umbilical cord from delivering oxygen and nutrients to the baby (and getting rid of excess carbon dioxide in the baby) can cause the baby to be permanently injured. When a baby is deprived of oxygen for too long, brain cells can start to die, causing hypoxic-ischemic encephalopathy (HIE), a brain injury that can lead to seizurescerebral palsy, intellectual disabilities, and other conditions. Placental abruption is a complication in which the placenta separates from the inner wall of the uterus while the baby is still in the womb, disrupting normal nutrient and oxygen transport. This can be very dangerous for the baby. If the separation occurs at the umbilical cord – which means the umbilical cord is no longer attached to the womb – the baby will be completely cut off from the mother’s circulation and will not be receiving any oxygen or nutrients.

Risk Factors and Causes of Placental Abruption

  • History of prior C-section
  • Women who have given birth before
  • Mother over the age of 35 or younger than 20
  • Mothers with chronic (long-term) high blood pressure (hypertension/preeclampsia). This is the most common cause of placental abruption, and it occurs in approximately 44% of cases.
  • Trauma to the abdomen (e.g., from a car accident). The effect of trauma may not be immediately obvious. However, over the course of 24 hours, even mild trauma may progress to a significant degree of abruption.
  • Sudden decompression of the uterus from events such as the delivery of the first child in a multiples birth, amniotomy (physician breaks the mother’s water), or premature rupture of the membranes (PROM). This is particularly threatening in cases of polyhydramnios.
  • Accidental puncture of the placenta (e.g., during amniocentesis)
  • Chorioamnionitis (infection of the two membranes of the placenta and the amniotic fluid)
  • Previous placental abruption
  • Abnormal uterine blood vessels
  • Nutritional deficiency, especially folic acid (a B vitamin)
  • High levels of a protein called alph-fetoprotein
  • A male baby
  • Other less common causes include uterine fibroids, uterine surgery, injury to the uterus (e.g. car accident), and cigarette smoking.

Signs and Symptoms of Placental Abruption:

These may include:

  • Internal bleeding (occurs roughly 30-40% of the time)
  • Low blood pressure
  • Tachycardia
  • Placental abruption progression
  • Bleeding during the second half of pregnancy or excessive bleeding during labor
  • Intense abdominal pain
  • Uterine contractions during labor that last longer than normal
  • Uterus that becomes hard to the touch during labor
  • Fetal distress
  • Uterine irritability

Placental Abruption Diagnosis: Close Monitoring Is Critical

Placental abruption can occur during pregnancy after 20 weeks of gestation. When abruption occurs, there may be a small amount of vaginal bleeding or massive hemorrhage (sudden, uncontrolled bleeding), leading to severe injury and even death of the baby, as well as a blood clotting problem that can be devastating for the mother and baby. However, the diagnosis of placental abruption may be delayed if the bleeding is concealed. In fact, in approximately 20% of cases, there is no vaginal bleeding. When bleeding is not visible, reliance on the magnitude of visible bleeding may cause the physician to seriously underestimate the amount of blood loss. Physicians must be aware of this and of the possibility of concealed bleeding, and must pay very close attention to signs and symptoms of abruption. In many cases of placental abruption, the baby must be delivered early.

In most cases, the diagnosis of placental abruption is made based only on the signs, symptoms, and medical history of the mother, and it can later be confirmed by finding clots on the placenta after delivery. Ultrasound examination might not reveal concealed bleeding, so it can only be used to exclude the presence of other conditions. Since the diagnosis of this very serious condition is mostly based on observation, it is imperative for the physician to communicate with and pay very close attention to the mother and baby, especially if the mother has risk factors for abruption. Monitoring fetal heart rate is critical since nonreassuring fetal heart tracings are a sign of the baby being oxygen deprived and in distress.

When a mother has high blood pressure during pregnancy, called preeclampsia, she may be at higher risk for placental abruption; research shows that preeclampsia and abruption often occur together. When these conditions occur together, the baby’s risk of experiencing oxygen deprivation is even greater because preeclampsia also can cause oxygen deprivation in the baby. Thus, when preeclampsia and placental abruption occur at the same time, the baby is experiencing two different conditions that cause a deprivation of oxygen.

Management of Placental Abruption Differs Based On Severity

The severity of placental abruption and the potential level of damage a baby might sustain is based on:

  • The location of the separation
  • The size of the separation
  • How much reserve the baby has
  • How much time goes by from the time the placental abruption occurred until the baby is delivered
  • The age of the baby

Severe Placental Abruption

If the placental separation is complete or severe, the baby will have to be delivered immediately in order to prevent severe brain damage caused by oxygen deprivation. Types of brain damage that can occur include hypoxic-ischemic encephalopathy (HIE), cerebral palsy, periventricular leukomalacia (PVL), and intellectual and developmental disabilities.
If there is any suspicion of placental abruption, urgent delivery is indicated when:
The mother is unstable (regardless of the age of the baby). The mother is unstable when:

  • her blood pressure is low, and/or
  • she is having major blood loss, and/or
  • the ability of her blood to clot is significantly impaired (coagulopathy).


  • The baby’s heart rate is abnormal/nonreassuring (regardless of the age of the baby). The baby’s heart rate is one indicator of distress and severity of the abruption. When placental abruption is suspected, the mother and baby must be closely monitored. If a baby is deprived of sufficient oxygen, the heart rate can become too fast (tachycardia), irregular, or really slow (bradycardia).


  • The baby’s gestational age is 36 weeks or greater.

Prompt C-section is also indicated if vaginal delivery is contraindicated (in cases of malpresentation or prior classical C-section), or unsuccessful (failure to progress). When the baby has a slow heart rate, research shows improved outcomes when the C-section occurs within 18 minutes of the decision to perform a C-section. In many cases of placental abruption, there is poor placental blood flow and the baby is deprived of some or a lot of oxygen. In these cases, it is crucial to deliver the baby as soon as possible (in a matter of minutes). The longer a baby lacks sufficient oxygen, the more likely it is that brain damage will occur.

Even if the baby is not old enough or the lungs are not mature, delivery may still be required if the baby is in trouble.

Vaginal delivery is reasonable only if the mother is stable and the fetal heart tracing is reassuring. With significant abruption, the mother is often contracting vigorously. In cases of vigorous contractions, it is absolutely crucial that the baby be promptly delivered because fast and forceful contractions can deprive a baby of oxygen and cause HIE. In this case, then, close fetal monitoring should be ongoing and preparations should be made for an emergency C-section, which includes notifying the anesthesia team so they are ready. An attempt at vaginal delivery should only be undertaken if there is access to immediate C-section delivery.

Nonsevere Placental Abruption At 34-36 Weeks

For women between 34 and 36 weeks with probable minor abruption (minimal signs and symptoms), conservative management is a reasonable approach if the mother is stable, the baby’s status is reassuring, lab tests are normal, and active bleeding has stopped. However, as mentioned above, these women are at risk of a severe abruption; therefore, the baby and mother should be monitored very closely and delivery should occur if there is recurrent bleeding.

If the separation is not severe, the pregnancy must be very closely monitored, and delivery may be indicated if the baby is old enough. In fact, even in cases of mild abruption, the standard of care is to deliver the baby if the baby is old enough and the lungs are mature. The reason for this is because a mild or moderate placental abruption can turn severe very quickly. If a baby can be delivered, it is not worth the risk of continuing gestation. Delivery should occur in most patients with a new diagnosis of abruption at 34 – 36 weeks – even if the abruption is not severe – due to the fact that there is a high risk of a severe abruption occurring very quickly.

Nonsevere Placental Abruption At Less Than 34 Weeks

Expectant management (waiting for delivery to occur naturally) is reasonable in cases of abruption in pregnancies less than 34 weeks when the mother is stable and tests of the baby’s well-being (such as heart rate tests) are reassuring. Waiting for labor can give the baby’s lungs and other systems a longer chance to develop. Women with pregnancies between 23 and 34 weeks of gestation should be given steroids to help the babies’ lung maturity. Abruption increases the chances that a baby will be born prematurely.

If no further symptoms develop in these mothers, delivery can be scheduled at 37 – 38 weeks because the risk of stillbirth is very high. However, if additional complications arise (intrauterine growth restriction, preeclampsia, PROM, nonreassuring fetal assessment, or recurrent abruption with maternal instability), delivery before 37 weeks must take place.

In general, when placental abruption is suspected and bleeding is present (either concealed or visible), the mother and baby should be closely monitored in the hospital until the bleeding has subsided for at least 48 hours, fetal heart tracings and ultrasound exams are reassuring, and the mother has no symptoms of abruption. Monitoring must include fetal heart rate and maternal hemodynamic monitoring, including blood pressure, volume, and heart rate. This is the minimum type of general management that should occur, and in some cases, the mother and baby should remain in the hospital for a longer period of time.

Even in cases of mild placental abruption, the baby could be receiving a decreased supply of oxygen and nutrients. An ongoing reduction in the supply of oxygen and nutrients can cause very serious problems in the baby, such as intrauterine growth restriction and brain damage.

Standards of Care and Placental Abruption

It is imperative for physicians to monitor for and treat high blood pressure in a pregnant woman since high blood pressure can cause placental abruption.

The management of bleeding during pregnancy requires sound medical judgment. The health of the baby at a given gestational age must be measured against the likely impact the bleeding has on maternal and fetal well-being and the long-term outlook for the pregnancy if the mother were to wait for labor and delivery to occur naturally.

Mothers with evidence of abruption must be hospitalized. Many different blood component therapies can be used to reduce the risk of infection, prevent blood clotting and bleeding problems, and increase the blood’s ability to carry oxygen to the mother and baby. Certain fluids may need to be given to the mother to keep her blood pressure up. Low blood pressure can decrease the amount of oxygen-rich blood going to the baby, and this can cause injury and even permanent brain damage if the blood pressure is too low for too long. Proper fluid therapy is critical when the mother is in shock.

If the bleeding is severe, the baby must be promptly delivered by emergency C-section. Research indicates that C-section reduces the risk of injury and death in the baby; in most cases, this method of delivery is usually the best choice. In many cases, the baby should be delivered in less than 18 minutes in order to avoid permanent brain damage from HIE.

It is essential for physicians to closely monitor a mother at risk of having a placental abruption, and if signs of the condition are present, very close and continuous monitoring must occur, and the physician must be prepared to do a quick C-section delivery. Preparation and expediency are crucial because a baby can suffer brain damage if a timely C-section is not performed. The mother must be made aware of the risks and alternatives to the various management options for abruption, so that she can provide informed consent.

Placental abruption deprives a baby of oxygen, sometimes only a little, and sometimes a significant amount. Oxygen deprivation in the baby must be avoided, so quick delivery is critical when the baby or mother are in distress.

Award-Winning Placental Abruption AttorneysBirth Injury Law | Reiter & Walsh, PC

If you experienced a placental abruption and your child was diagnosed with a birth injury such as cerebral palsy, a seizure disorder, or hypoxic-ischemic encephalopathy (HIE), the birth injury attorneys at ABC Law Centers can help. We have helped children throughout the country obtain compensation for lifelong treatment and therapy, and we give personal attention to each child and family we represent. Our firm has numerous multi-million dollar verdicts and settlements that attest to our success, and no fees are ever paid to us until we win your case. Email or call Reiter & Walsh ABC Law Centers at 888-419-2229 for a free case evaluation.

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Related Resources

Video: Placental Abruption and Hypoxic Ischemic Encephalopathy (HIE)

birth injury lawyers and placental abruption attorneysWatch a video of Jesse Reiter discussing how a prompt C-section delivery can prevent a baby from experiencing prolonged birth asphyxia and resultant hypoxic ischemic encephalopathy when obstetrical emergencies – such as a placental abruption – occur.