(235) Severe maternal morbidity among people with cardiac disease: getting to the heart of the problem

People with cardiac disease have higher rates of severe maternal morbidity (SMM), including cardiac SMM. However, little is known about the risk of other types of SMM in this population. We examined differences in SMM indicator events between people with and without cardiac disease in pregnancy.

Study Design:

Using linked birth certificate and hospital discharge record data, we performed a cohort study to examine SMM and non-transfusion SMM in singleton deliveries at 20-44 weeks of gestation in California from 2007-2018, in people with and without cardiac disease prior to delivery. We identified cardiac disease using diagnosis codes for congenital cardiac disease, acquired cardiomyopathy, ischemic heart disease, valvular disease, and arrhythmias. We excluded hypertensive disorders and acute or transient cardiac disease such as viral myocarditis. Diagnoses codes were used to identify the primary outcomes (SMM and non-transfusion SMM) and their indicator events up to 42 days postpartum. Logistic regression models were conducted, adjusting for confounding factors.

Results:

Of 5,020,230 singleton births, 17,938 (0.4%) were to people with cardiac disease prior to pregnancy. This cohort was older, had a higher level of education, private insurance, and lower BMI and initiated prenatal care earlier. People with cardiac disease had a higher risk of overall SMM (12.1% vs 1.5%, odds ratio [OR] 8.81 [95% CI 8.42 -9.23]) and non-transfusion SMM (9.5% vs 0.7%, OR 13.85 [95% CI 13.16 -14.58]). When grouped by organ system, all SMM indicator events were significantly more common in people with cardiac disease, with especially higher odds of cardiac SMM (OR 89.55 [95% CI 82.63-97.04]) and pulmonary SMM (OR 30.35 [95% CI 27.53 - 33.45]) (Table 1, Figure 1).

Conclusion:

People with cardiac disease prior to pregnancy are at significantly increased risk of all types of SMM indicator events, notably cardiac, pulmonary, renal, and other OB SMM. These results may inform risk reduction strategies to mitigate these health disparities and reduce maternal morbidity during delivery and postpartum in this high risk population.