Racial/ethnic disparities in the risk of preterm birth among women with systemic lupus erythematosus or rheumatoid arthritis

Objective: In a large multi-racial/ethnic cohort of women, we examined racial/ethnic disparities in preterm birth (PTB) risk stratified by autoimmune rheumatic disease (ARD) type, which included systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Methods: Birth records linked to hospital discharge data of singleton births in California from 2007 to 2012 were leveraged for a retrospective cohort study including women with SLE or RA. The relative risk of PTB (< 37 versus ≥ 37 weeks’ gestation) was compared among different racial/ethnic groups (Asian, Hispanic, Non-Hispanic (NH) Black, and NH White) and stratified by ARD type. Results were adjusted for relevant covariates using Poisson regression. Results: We identified 2874 women with SLE and 2309 women with RA. NH Black, Hispanic, and Asian women with SLE were 1.3 to 1.5 times more likely to have PTB compared to NH White women. NH Black women with RA were 2.0 to 2.4 times more likely to have PTB compared to Asian, Hispanic, or NH White women. The NH Black-NH White and NH Black-Hispanic disparity in PTB risk was significantly higher in women with RA compared to SLE or the general population. Conclusion: Our findings highlight the racial/ethnic disparities for risk of PTB among women with SLE or RA and highlight that several of the disparities are higher for women with RA compared to those with SLE or the general population. These data may provide important public health information for addressing racial/ethnic disparities in the risk of preterm birth, particularly among women with RA.Key Points• There is an unmet need for studies that evaluate racial/ethnic disparities in birth outcomes specifically in women with RA or SLE.• This is one of the first studies describing racial/ethnic disparities in PTB risk for women with RA, and to draw conclusions regarding Asian women in the USA with rheumatic diseases and PTB.• These data provide important public health information for addressing racial/ethnic disparities in the risk of preterm birth among women with autoimmune rheumatic diseases.