Amniotic fluid embolism: Decreased mortality in a population-based study

Objective: To examine the risk factors and pregnancy outcomes associated wi th 53 cases of amniotic fluid embolism that occurred in California during t he 2-year period January 1, 1994 to December 31, 1995. Methods: Data were obtained from a computerized database that contains link ed records from the vital statistics birth certificate and hospital dischar ge summaries of both mother and newborn. This database covered all singleto n deliveries that occurred in 328 civilian acute-care hospitals in Californ ia, which represented 98% of all deliveries in California. All cases of amn iotic fluid embolism were examined for other pregnancy complications. Results: There were 1,094,248 deliveries during that P-year period. Fifty-t hree singleton gestations had the diagnosis of amniotic fluid embolism, for a population frequency of one per 20,646 deliveries. Fourteen women with a mniotic fluid embolism died, for a maternal mortality rate of 26.4%. There were 35 (66%) diagnoses of disseminated intravascular coagulation (DIC), 38 (72%) diagnoses of hemorrhage, and 25 (47%) diagnoses of obstetric shock. Among the 14 women who died, the frequency of DIC (79%) and hemorrhage (71% ) was not different compared with that of the survivors (62% and 72%, respe ctively), but obstetric shock was higher (86%, P = .02) than in survivors ( 33%). The average maternal length of stay for sunrivors was 6.5 days (range 3-27 days, median 5 days). The cesarean rate was 60% and the frequency of fetal distress was 49%. Conclusion: In this population-based study of reported cases of amniotic fl uid embolism, the maternal mortality rate (26.4%) was significantly less th an previously reported and might reflect a more accurate population frequen cy. In addition, patients who survived and patients who died had similar pr egnancy complications, suggesting that amniotic fluid embolism was present in all cases and not limited to those who died. (Obstet Gynecol 1999;93:973 -7. (C) 1999 by The American College of Obstetricians and Gynecologists.)