Objective:  Maternal mortality rates rose markedly from 2002 to 2006 in California, prompting an in-depth maternal mortality review in a state that comprises one twelfth of the US birth cohort. Cardiovascular disease has emerged as the leading cause of pregnancy-related death in the United States. The primary aim of this analysis was to describe the incidence and type of cardiovascular disease as a cause of pregnancy-related mortality in California. The secondary aims were to describe racial/ethnic and socioeconomic disparities, risk factors, birth outcomes, timing of death and diagnosis, and signs and symptoms of cardiovascular disease and identify contributing factors.

Study Design:  The California Pregnancy-Associated Mortality Review retrospectively examined a case series of 64 cardiovascular pregnancy-related deaths from 2002 through 2006. Two cardiologists independently reviewed complete inpatient and outpatient medical records including laboratory, radiology, electrocardiogram, chest X-ray, echocardiograms, and autopsy findings for each cardiovascular death and classified cause of death by type of cardiovascular disease. Demographic data, racial disparities, risk factors, signs and symptoms, timing of diagnosis and death, birth outcomes, and contributing factors were analyzed using bivariate comparisons with noncardiovascular pregnancy-related deaths and population-based data.

Results:  Among 2,741,220 California women who gave birth, 864 died while pregnant or within 1 year of pregnancy; 257 of the deaths were deemed pregnancy related, and of these, 64 (25%) were attributed to cardiovascular disease. There were 42 deaths caused by cardiomyopathy, and the pregnancy-related mortality rate from cardiomyopathy was 1.54 per 100,000 births. Dilated cardiomyopathy existed in 29 cases, of which 15 met the definition of peripartum cardiomyopathy. Women with cardiovascular disease were more likely than women who died from noncardiovascular causes to be African-American (39.1% vs 16.1%; P < .01) and more likely to use illicit substances (23.7% vs 9.4%; P < .01). Thirty-seven percent were obese and 20% had a concomitant diagnosis of hypertension or preeclampsia during pregnancy. Health care decisions in the diagnosis or treatment of cardiovascular disease during and after pregnancy contributed to the fatal outcomes.

Conclusions:  African-American race, substance use, and obesity were risk factors for pregnancy-related cardiovascular disease mortality. Chronic disease prevention and better recognition and response to cardiovascular disease during pregnancy are needed to reduce maternal mortality.