Amniotic fluid embolism (AFE), also known as anaphylactoid syndrome of pregnancy, is a pregnancy complication that causes life-threatening conditions, such as heart failure.

It can affect you, your baby, or both of you. It happens when amniotic fluid (the fluid surrounding your unborn child) or fetal cells, hair, or other debris make their way into your blood.

AFE is rare. Though estimates vary, the AFE Foundation reports the condition occurs in only 1 out of every 40,000 deliveries in North America (and 1 in every 53,800 deliveries in Europe). However, it’s a leading cause of death during labor or shortly after birth.

AFE can occur during labor or shortly after giving birth in both vaginal and cesarean births. In rare cases, it can happen during an abortion or while having a small sample of amniotic fluid taken for examination (amniocentesis).

AFE is a negative reaction that occurs when amniotic fluid enters your circulatory system. It can’t be prevented, and the reason why this reaction occurs is unknown.

The first stage of AFE usually causes cardiac arrest and rapid respiratory failure. Cardiac arrest occurs when your heart stops working, and you lose consciousness and stop breathing.

Rapid respiratory failure occurs when your lungs can’t supply enough oxygen to your blood or remove enough carbon dioxide from it. This makes it very difficult to breathe.

Other possible symptoms include:

  • fetal distress (signs that the baby is unwell, including changes in the fetal heart rate or decreased movement in the womb)
  • vomiting
  • nausea
  • seizures
  • severe anxiety, agitation
  • skin discoloration

Women who survive these events may enter a second stage called the hemorrhagic phase. This occurs when there’s excessive bleeding either where the placenta was attached or, in the case of a cesarean birth, at the cesarean incision.

AFE can be fatal, especially during the first stage. Most AFE deaths occur due to the following:

  • sudden cardiac arrest
  • excessive blood loss
  • acute respiratory distress
  • multiple organ failure

According to the AFE Foundation, in roughly 50 percent of cases, women die within 1 hour after symptoms start.


Treatment involves managing symptoms and preventing AFE from leading to coma or death.

Oxygen therapy or a ventilator can help you breathe. Making sure that you’re getting enough oxygen is crucial so that your baby also has enough oxygen.

Your healthcare provider might request to have a pulmonary artery catheter inserted so that they can monitor your heart. Medications might also be used to manage your blood pressure.

In many cases, several blood, platelet, and plasma transfusions are needed to replace the blood lost during the hemorrhagic phase.


Your healthcare provider will monitor your baby and watch for signs of distress. Your baby will most likely be delivered as soon as your condition is stabilized. This increases their chances of survival. In most cases, babies are transferred to the intensive care unit for close observation.

AFE can’t be prevented, and it’s challenging for healthcare providers to predict if and when it will occur. If you’ve had AFE and planning to have another baby, it’s recommended that you talk to a high-risk obstetrician first.

They will discuss the risks of pregnancy beforehand and monitor you closely if you become pregnant again.


Per the AFE Foundation, estimated rates of mortality for women with AFE are varied. Older reports estimate that up to 80 percent of women don’t survive, although more recent data estimates that this number is about 40 percent.

Women who survive AFE can often have long-term complications, which can include:

Mental and emotional challenges can also occur, especially if the baby doesn’t survive. Health conditions may include postpartum depression and post-traumatic stress disorder (PTSD).


According to the AFE Foundation, estimated mortality rates for infants with AFE are also varied.

Around 30 percent of infants with AFE don’t survive, per a 2016 study published in the Journal of Anesthesiology Clinical Pharmacology.

The AFE Foundation reports that the mortality rate for infants still in the womb is around 65 percent.

Some infants who survive can have long-term or lifelong complications from AFE, which may include:

  • nervous system impairment that can be mild or severe
  • not enough oxygen to the brain
  • cerebral palsy, which is a disorder that affects the brain and nervous system