Racial differences in cardiovascular events and adverse pregnancy outcomes among pregnant individuals with SLE

OBJECTIVE: We aimed to characterise differences in the occurrence of maternal cardiovascular events (CVEs) and adverse pregnancy outcomes (APOs) in each of four racial/ethnic groups compared with non-Hispanic white women with SLE and to evaluate whether the relationship between CVEs and APOs differed across or within racial/ethnic groups. METHODS: Using a California population-based birth cohort (2005-2020), we identified pregnant individuals with SLE via International Classification of Diseases codes from maternal discharge records. Self-reported racial/ethnic groups were categorised as Asian, Hispanic, non-Hispanic black, non-Hispanic white and other. Individuals with reported race or ethnicity as 'unknown' or 'not stated' were excluded from the study. Log-linear regression estimated adjusted relative risks (aRRs) of CVEs and APOs in each racial/ethnic group compared with non-Hispanic white individuals, adjusting for a propensity score derived from maternal age, payer, education, comorbidities and SLE-related variables. We performed CVE-stratified analyses for racial/ethnic differences in APOs and examined associations between CVEs and APOs within each racial/ethnic group. RESULTS: Among 8188 liveborn singletons from women with SLE, non-Hispanic black women had the highest prevalence of maternal CVEs (4.0% vs 1.6-2.0% in other groups), maternal APOs (24.6% vs 13.5-17.2%) and infant APOs (54.6% vs 34.6-49.4%). Relative to non-Hispanic white women, non-Hispanic black women had an aRR of 1.6 (95% CI 0.9 to 2.6) for maternal CVEs and 1.3 (95% CI 1.1 to 1.6) for maternal APOs, whereas infant APO risks were significantly higher across three of four racial/ethnic groups compared with non-Hispanic white women. CONCLUSIONS: Non-Hispanic black women exhibited the highest absolute burden for the adverse outcomes studied. Relative to non-Hispanic white individuals, elevated adjusted risks based on race/ethnicity were most consistent for infant APOs, whereas elevated risks for maternal APOs and CVEs were found primarily among non-Hispanic black individuals. Social drivers of health need consideration while caring for pregnant individuals with SLE.