Amniotic fluid embolism (AFE) is a rare obstetric emergency in which amniotic fluid, fetal cells, hair, or other debris enters the mother's blood stream via the placental bed of the uterus and trigger an allergic reaction. This reaction then results in cardiorespiratory (heart and lung) collapse and coagulopathy. 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.
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.
The pathophysiology of AFE is speculative, various theories have been published. In 1995, Clarke suggested that the syndrome arose from an immune rather than embolic process. Amniotic fluid embolism is caused by fetal antigens in the amniotic fluid stimulating a cascade of endogenous immune mediators, producing a reaction similar to anaphylaxis. Biochemical mediators found in the amniotic fluid are thought to trigger the main features of anaphylactic reaction with multisystem involvement.