Amniotic fluid embolism (AFE) 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 says it occurs in only one in every 40,000 deliveries in North America (and one in every 53,800 deliveries in Europe). However, it is a leading cause of death during labor or shortly after birth. Areas where AFE is a high-ranking cause of mortality include:
- the United Kingdom
- the United States
AFE can happen 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 an adverse reaction that occurs when amniotic fluid enters your circulatory system. It cannot be prevented, and the reason why this reaction occurs is unknown.
The first stage of AFE usually includes 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 cannot 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)
- severe anxiety, agitation
- skin discoloration
Women who survive these events may enter a second stage called the hemorrhagic phase. This occurs when there is 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, death occurs within an hour after symptoms start in roughly 50 percent of cases.
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 are getting enough oxygen is crucial so that your baby also has enough oxygen. You also might have a pulmonary artery catheter inserted so that your doctors can monitor your heart. Medications might also be used to control your blood pressure. In many cases, several blood, platelet, and plasma transfusions are needed to replace the blood lost during the hemorrhagic phase.
Your doctor 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 end up in the intensive care unit for close observation.
Estimated rates of mortality for women with AFE are varied. Older reports estimate that up to 80 percent of women do not survive, although more recent data estimates that this number is about 40 percent. Women who do survive AFE often have long-term complications. These can include:
- memory loss
- organ failure
- heart damage that can be short-term or permanent
- nervous system problems
- a partial or complete hysterectomy
- damage to the pituitary gland
Emotional problems can also occur, especially if the baby does not survive. These problems include postpartum depression and post-traumatic stress disorder.
Estimated rates of mortality for infants with AFE are also varied. Around 30 percent of infants with AFE do not survive, according to the Journal of Anesthesiology Clinical Pharmacology. However, the AFE Foundation reports that the mortality rate for infants still in the womb can be as high as 65 percent. Some infants who do survive have long-term or lifelong complications from AFE. These 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
AFE cannot be prevented, and doctors find it hard to predict if and when it will occur. If you have had AFE and plan on trying to have another baby, talk to a high-risk obstetrician first. Your doctor will discuss the risks of pregnancy beforehand and watch you closely if you do become pregnant again.