Low aspirin use and high prevalence of pre-eclampsia risk factors among pregnant women in a multinational SLE inception cohort

Women with systemic lupus erythematosus (SLE) carry a substantially higher risk for pre-eclampsia compared with the general population.1 Aspirin reduces the risk of pre-eclampsia in high-risk pregnancies by more than half2 and thus is recommended in SLE.3–5 The European League Against Rheumatism recommends aspirin in SLE pregnancies, particularly in those with nephritis or positive antiphospholipid antibodies (aPL).5 Despite this, little is known about current practice. Therefore, we assessed the prevalence of aspirin use in SLE pregnancies within the Systemic Lupus International Collaborating Clinics inception cohort, which has been described elsewhere.6 SLE women aged 18–45 with a pregnancy documented at one or more annual study visits (spanning 2000–2017) were included. For each pregnant visit, aspirin use, traditional pre-eclampsia risk factors (hypertension, chronic kidney disease, diabetes, nulliparity, body mass index ≥35, age >40), aPL and active lupus nephritis were assessed (see variable definitions in online supplementary material). Aspirin use was compared among those with and without each/any risk factor, and over time. We identified 475 pregnancies among 300 women. Mean SLE duration at the time of pregnancy was 5.6 years (SD 3.1). Half (51%) of pregnancies had ≥1 traditional pre-eclampsia risk factor, 34/104 (33%) had positive aPL and 53/475 (11%) had …