Objective: To examine trends in spontaneous abortion-related mortality and risk factors for these deaths from 1981 through 1991.
Methods: We used national data from the Centers for Disease Control and Prevention's Pregnancy Mortality Surveillance System to identify deaths due to spontaneous abortion (less than 20 weeks' gestation). Case-fatality rates were defined as the number of spontaneous abortion-related deaths per 100,000 spontaneous abortions. We calculated annual case-fatality rates as well as risk ratios by maternal age, race, and gestational age.
Results: During 1981-1991, a total of 62 spontaneous abortion-related deaths were reported to the Pregnancy Mortality Surveillance System. The overall case fatality rate was 0.7 per 100,000 spontaneous abortions. Maternal age 35 years and older (risk ratio [RR] 1.7, 95% confidence interval [CI] 0.9-3.0), maternal race other than white (RR 3.8, 95% CI 2.2-5.9), and gestational age over 12 weeks (RR 8.0, 95% CI 4.2-11.9) were risk factors for death due to spontaneous abortion. Of the 62 deaths, 59% were caused by infection, 18% by hemorrhage, 13% by embolism, 5% from complications of anesthesia, and 5% by other causes. Disseminated intravascular coagulation (DIC) was an associated condition among half of those deaths for which it was not the primary cause of death.
Conclusion: Women 35 years of age and older, of races other than white, and in the second trimester of pregnancy age are at increased risk of death from spontaneous abortion. In addition, DIC complicates many spontaneous abortion cases that end in death. Because spontaneous abortion is a common outcome of pregnancy, continued monitoring of spontaneous abortion-related deaths is recommended.