Risk factors

It's estimated that there are between one and 12 cases of amniotic fluid embolism for every 100,000 deliveries. Because amniotic fluid embolisms are rare, it's difficult to identify risk factors.

Research suggests that several factors might be linked to an increased risk of amniotic fluid embolism, however, including:

• Advanced maternal age. If you're 35 or older at the time of your child's birth, you might be at increased risk of amniotic fluid embolism.
• Placenta problems. Abnormalities in the placenta — the structure that develops in your uterus during pregnancy — might increase your risk of amniotic fluid embolism. Abnormalities might include the placenta partially or totally covering the cervix (placenta previa) or the placenta peeling away from the inner wall of the uterus before delivery (placental abruption). These conditions can disrupt the physical barriers between you and your baby.
• Preeclampsia. Having high blood pressure and excess protein in your urine after 20 weeks of pregnancy (preeclampsia) can increase your risk.
• Medically induced labor. Limited research suggests that certain labor induction methods are associated with an increased risk of amniotic fluid embolism. Research on this link, however, is conflicting.
• Operative delivery. Having a C-section, a forceps delivery or a vacuum extraction might increase your risk of amniotic fluid embolism. These procedures can disrupt the physical barriers between you and your baby. It's not clear, however, whether operative deliveries are true risk factors for amniotic fluid embolism because they're used after the condition develops to ensure a rapid delivery.
• Polyhydramnios. Having too much amniotic fluid around your baby may put you at risk of amniotic fluid embolism.