Amniotic fluid embolism (AFE) is a rare but potentially fatal condition related to pregnancy. It occurs when the amniotic fluid that surrounds an infant during pregnancy enters the bloodstream of the mother. AFE can also sometimes develop during pregnancy as a result of other fetal matter, including fetal cells, getting into the mother's bloodstream. AFE is most likely to occur during delivery or in the time period immediately after delivery.
AFE is a rare condition of pregnancy, but it is extremely serious and can often be fatal. Research has indicated that it occurs in roughly 1 in every 40,000 deliveries in North America, while the incidence rate in Europe is 1 in 53,800. In the United States, AFE is the cause of between 7.5% and 10% of all maternal mortality.
According to the Journal of Anesthesiology Clinical Pharmacology, the Amniotic Fluid Embolism survival rate for infants is estimated to be around 70% but a report by the AFE Foundation put the mortality rate for infants in the womb at 65%.
The condition is caused by the body having an adverse reaction to amniotic fluid or amniotic matter entering the bloodstream. The precise reason why this reaction occurs is not yet fully understood. AFE can occur in both vaginal and caesarean births and occurs either during labor itself or immediately following birth. In rare cares, it has been known to occur during abortion or while undergoing amniocentesis.
The symptoms of AFE occur quickly. The first stage involves respiratory failure and cardiac arrest. The respiratory failure is caused by the inability of the lungs to supply sufficient oxygen, making it hard to breathe. Cardiac arrest takes place when the heart ceases to function and leads to loss of consciousness and the cessation of breathing. There are other symptoms that can indicate AFE and these include:
Women who survive the first stage of AFE may suffer a second stage of symptoms, characterized by excessive bleeding. This occurs either in the position where the placenta was attached or at the caesarean incision if the birth is by caesarean. Most AFE deaths occur due to cardiac arrest, acute respiratory problems, organ failure or blood loss.
For mothers suffering from AFE, treatment is focused on managing the symptoms. Oxygen therapy or a ventilator might be required to ensure correct breathing and that sufficient oxygen is reaching the baby. A pulmonary artery catheter may also be inserted so that doctors can monitor the mother's heart. Blood and plasma transfusions are often required during the hemorrhagic second phase, along with blood pressure medication.
When AFE occurs, doctors will carefully monitor the infant for any distress signs. In most cases, the baby will be delivered once the mother's condition has stabilized, which significantly increases infant survival rates. Once delivered, babies are transferred to an intensive care unit where they are closely observed for several days.
Women who survive AFE can have a range of problems. These include organ failure, memory loss, short or long-term heart damage, nervous system difficulties, or pituitary gland damage, and, in some cases, a complete or partial hysterectomy is required. AFE survivors can also develop emotional problems including post-traumatic stress disorder or post-partum depression, particularly if the baby did not survive.
Infants who survive AFE can also experience complications including impairment to the nervous system that can range from mild to severe, conditions related to insufficient brain oxygen supply and cerebral palsy, a disorder of the brain and nervous system.
The risk factors for AFE may include maternal age, the choice of a cesarean delivery, placenta problems and labor that is medically induced, but the condition is not preventable, and it is extremely difficult for medical professionals to predict.
If a woman has previously experienced AFE and is planning on having another baby, she is often advised to consult a high-risk obstetrician to fully discuss the risks of pregnancy and will be closely monitored during any subsequent pregnancy.