Amniotic Fluid Embolism

Amniotic fluid embolism (AFE) is a rare and life-threatening complication that occurs when amniotic fluid gets into your bloodstream just before, during or immediately after childbirth. It can happen during both vaginal and C-section deliveries.

Amniotic fluid is made mostly of water, but it also contains fetal cells and tissue. It’s normal for a small amount of amniotic fluid to mix with the mother’s bloodstream during childbirth. Most people don't have a reaction. But in rare cases, it can trigger a severe allergic response.

AFE can cause your heart and lungs to stop working correctly. It can lead to serious complications, including cardiac arrest (when your heart stops beating) and severe, uncontrolled bleeding. AFE happens suddenly and is unpredictable. It can be challenging to treat, but your care team will act quickly to give you emergency medical care.

It’s difficult to estimate exactly how many people AFE affects. But experts believe it occurs in about 1 in 20,000 to 1 in 50,000 births.

It’s also known as anaphylactic syndrome of pregnancy or amniotic embolism.

Symptoms of amniotic fluid embolism

Signs and symptoms of AFE develop quickly, most often at or within minutes of delivery. Possible symptoms include:

• Shortness of breath or difficulty breathing
• Sudden drop in blood pressure
• Rapid heart rate
• Severe bleeding that won’t stop
• Changes in your baby’s heart rate before birth
• Agitation, confusion or sudden anxiety
• Loss of consciousness

Your care team will notice these symptoms and act quickly to treat them.

Complications of amniotic fluid embolism

AFE can cause serious complications for you and your baby. For you, these include:

• Heart and lung failure
• Seizures
• Uncontrolled bleeding
• Stroke
• Cardiac arrest
• Brain damage
• Death

AFE can cause serious complications for your baby, especially if it happens during labor. Your pregnancy care provider may need to deliver your baby quickly. AFE can reduce the amount of oxygen your baby receives, which may lead to brain injury, nervous system problems or other complications.

This is a lot to take in. But remember that AFE isn’t your fault. And there’s nothing you can do to prevent it. But your care team will do everything they can to prevent these complications.

Amniotic fluid embolism causes

There’s no known cause of AFE. It’s rare and unpredictable.

During labor and delivery, amniotic fluid or material from the placenta can enter your bloodstream and trigger a severe immune response. Researchers aren’t sure why this happens.

Risk factors

It’s difficult to know who’s at risk for AFE because the condition is so rare and hard to study. But some possible risk factors include:

• Expecting multiples (twins, triplets or more)
• Issues with the placenta, like placental abruption
• Preeclampsia or eclampsia
• Having a C-section delivery
• Too much amniotic fluid
• Cervical lacerations
• Uterine rupture
• Being older than 35
• Fetal distress
• Labor induction

How doctors detect amniotic fluid embolism

AFE is diagnosed based on your symptoms and how quickly they develop. AFE typically occurs within 30 minutes of delivery. If it happens, you’ll need treatment right away.

Your provider may diagnose AFE if the following symptoms happen:

• Sudden drop in blood pressure
• Difficulty breathing
• Irregular heart rate or your heart stops beating entirely
• Excessive bleeding with no explanation

There’s no single test that can confirm AFE. Your care team will rely on vital signs and other measurements to diagnose it.

AFE often happens in two phases, and you may not have both:

• Phase one: AFE usually begins with sudden heart and lung problems. This may include trouble breathing, low oxygen levels, a sudden drop in blood pressure or cardiac arrest. This phase is the most life-threatening.
• Phase two: People who survive the first phase may develop severe bleeding because their blood can no longer clot normally. This may cause heavy bleeding from the uterus or C-section incision.

How is amniotic fluid embolism treated?

Amniotic fluid embolism is an emergency. Treatment for this condition needs to happen very quickly to protect you and your baby. Possible treatments include:

• Immediate delivery of your baby
• Cardiopulmonary resuscitation (CPR)
• Multiple blood, plasma and platelet transfusions
• Hysterectomy to stop bleeding
• Oxygen by using tracheal tube or mechanical ventilation
• Steroids or other medications to help your blood pressure or heart

What’s the survival rate for AFE?

The survival rate depends on many factors, like when AFE is detected and how serious it is. One study found that the survival rate was about 83%, meaning 8 in 10 survive.

If you’re concerned about AFE or other childbirth complications, talk with your pregnancy care provider. They can answer your questions and explain how your healthcare team responds to emergencies during labor and delivery.

What are the long-term effects for people who survive?

It depends on how severe your case of AFE is and your health history. Side effects can impact your body and mind. Some long-term effects could include:

• Brain damage that affects your memory or word recall
• Permanent heart damage
• Complications from stroke (if you have one)
• Post-traumatic stress disorder (PTSD)
• Anxiety, depression and feelings of guilt

If you have questions about the effects of AFE, your healthcare provider is the best resource for answers. If you experience signs of birth trauma, reach out to a mental health specialist for care.