(1071) Congenital heart disease in pregnancy and severe maternal morbidity: a distributed data network study

A growing number of pregnant people have congenital heart disease (CHD), but the limitations of traditional study designs and data sources have resulted in insufficient evidence on outcomes for these patients. We leveraged a distributed data network of electronic health record (EHR) data through the Observational Medical Outcomes Partnership (OMOP) common data model (CDM) to assess the incidence of severe maternal morbidity (SMM) among pregnant people with and without CHD.

Study Design:

Our distributed data network study included female patients aged 12-55 who delivered at three U.S. academic healthcare institutions with EHRs converted into the OMOP CDM. Analytical code was developed at the primary study institution and then executed locally at all sites. We used OMOP standard concepts to identify CHD and SMM from structured and unstructured EHR data. Following the CDC definitions, we identified SMM indicators occurring between one month prior to delivery through 6 weeks postpartum. We categorized outcomes as SMM, non-transfusion SMM, and cardiac SMM. We analyzed demographic characteristics and incidence of the outcomes by CHD status, by site and aggregated across sites.

Results:

CHD prevalence was 2.0% among 149,212 deliveries across three sites. Distribution of race and ethnicity varied by site and age distribution was similar across sites (Table 1). SMM occurred in 9.0% of deliveries to people with CHD compared to 3.9% among people without CHD, and non-transfusion SMM occurred in 6.2% vs 2.3% of deliveries, respectively. Cardiac SMM represented 50% of non-transfusion SMM cases among people with CHD compared to 16% of cases among people without CHD (Table 2).

Conclusion:

Our distributed network study of EHR data from three geographically diverse U.S. healthcare institutions found that 1 in 11 people with CHD had SMM compared with 1 in 26 people without CHD. This study provides novel evidence for counseling obstetric patients with CHD and lays the groundwork for expanded network studies on CHD in pregnancy.