Pregnancy outcomes in a diverse US Lupus Cohort.

OBJECTIVE: Although the systemic lupus (SLE) patient population is racially and ethnically diverse, many study populations are homogeneous. Further, data are often lacking on critical factors such as antiphospholipid (aPL) antibodies. We investigated livebirth rates in patients with SLE at Kaiser Permanente Northern California including race/ethnicity and aPL data.

METHODS: Electronic health records of pregnancies with outcomes observed from 2011-2020 were identified among patients with SLE. Prevalent SLE was defined as ≥2 ICD coded visits ≥7 days apart before the last menstrual period (LMP). We summarized patient characteristics, medication orders, and healthcare utilization, and medication use. Pregnancy outcomes (livebirth, stillbirth, spontaneous abortion, ectopic, molar) were presented overall, and stratified by race/ethnicity, aPL status, and nephritis history.

RESULTS: We identified 657 pregnancies among 453 patients with SLE. The cohort was diverse reflecting the Northern California population (27% Asian, 26% Hispanic, 26% Non-Hispanic (NH) White, 13% NH Black, 5% Multiracial, about 2% Islander, Native American). Approximately 74% of observed pregnancies ended in livebirth, 23% resulted in spontaneous abortion, 2% were ectopic or molar pregnancies, and <1% were stillbirths. There was limited variability in livebirths by race/ethnic group (72%-79%), aPL (69.5%-77%), and nephritis (71%-75%) CONCLUSION: Our findings are consistent with previous studies, however, some methodologic differences may yield a range of livebirth rates. We found that approximately 74% of pregnancies in SLE ended in livebirth, with modest variability in spontaneous abortion by race/ethnicity, nephritis, and aPL.