Amniotic Fluid Embolism - Causes

Causes

It is mostly agreed that this condition results from amniotic fluid entering the uterine veins and in order for this to occur there are three prerequisites:

• Ruptured membranes (a term used to define the rupture of the amniotic sac)
• Ruptured uterine or cervical veins
• A pressure gradient from uterus to vein

Although exposure to fetal tissue is common and thus finding fetal tissue within the maternal circulation is not significant, in a small percentage of women this exposure leads to a complex chain of events resulting in collapse and death.

There is some evidence that AFE may be associated with abdominal trauma or amniocentesis. A 2006 study showed that the use of drugs to induce labor, such as misoprostol, nearly doubled the risk of AFE. A maternal age of 35 years or older, caesarean or instrumental vaginal delivery, polyhydramnios, cervical laceration or uterine rupture, placenta previa or abruption, eclampsia, and fetal distress were also associated with an increased risk.