Amniotic fluid embolism: antepartum, intrapartum and demographic factors.

OBJECTIVE

To describe the incidence, antepartum, intrapartum and postpartum risk factors, and mortality rate of amniotic fluid embolism (AFE).

METHODS

We used 2001-2007 California health discharge data to identify cases of AFE by ICD-9 codes.

RESULTS

Of 3,556,567 deliveries during the time period, we identified 182 cases of AFE, resulting in a population incidence of 5.1 in 100,000. Twenty-four of the cases resulted in death, giving a case fatality rate of 13.2%. Non-Hispanic blacks had a higher than 2-fold odds of developing AFE. AFE increased significantly with maternal age, most significantly after age 39. Cardiac disease had a nearly 70-fold higher association with AFE, cerebrovascular disorders had a 25-fold higher association, while conditions such as eclampsia, renal disease, placenta previa and polyhydramnios had nearly 7- to 13-fold higher associations. Classical cesarean delivery, abruption placentae, dilation and curettage, and amnioinfusion were all procedures highly associated with AFE.

CONCLUSION

Several antepartum and peripartum conditions and procedures are associated with significantly higher risks of amniotic fluid embolism. This information may contribute to a better understanding of the pathophysiology of AFE and potentially help identify those at the highest risk of developing this morbid condition.