Second delivery rates and recurrence of adverse pregnancy outcomes in women with systemic lupus erythematosus: a nationwide population-based cohort study.

Abstract

To assess the rate of a second delivery and the recurrence of adverse pregnancy outcomes (APOs) in women with SLE compared with the general obstetric population. This nationwide population-based cohort study used Swedish registers to identify women with SLE who had a first singleton liveborn delivery after SLE diagnosis. Up to ten non-SLE comparators were matched on birth year and residence. Second delivery rates were evaluated among women whose first delivery occurred during 2003-2020, with follow-up for second deliveries until the end of 2021. Recurrence of ≥ 1 APO, preeclampsia, and preterm delivery was assessed among women with two deliveries during 2003-2022. Cox proportional hazards models estimated hazard ratios (HRs) for second delivery, and modified Poisson models estimated risk ratios (RRs) for APO recurrence, adjusted for maternal age, education, BMI, smoking, APOs, and caesarean section. Second delivery rates were analyzed in 543 women with SLE and 17 218 comparators. Over a median follow-up of 2.3 years, incidence rates of second delivery were 156 and 176 per 1,000 person-years in women with and without SLE, respectively (adjusted HR 0.89, 95% CI 0.80-0.99). The adjusted HR was 0.78 (0.63-0.96) among women with ≥1 APO in the first pregnancy. Women with SLE had a higher risk of recurrence of APOs, including preeclampsia (RR 1.38), preterm delivery (RR 2.31), and any APO (RR 1.54). Women with SLE have a lower rate of a second delivery and a higher recurrence risk of APOs, highlighting the need for individualized reproductive counseling and close monitoring.