Abstract Background/Aims Pregnancy in patients with systemic lupus erythematosus (SLE) is associated with significant maternal and obstetric risks, particularly in the context of antiphospholipid syndrome (APS). While these risks are well-documented, the impact of isolated antiphospholipid antibodies (aPL) without overt APS remains unclear. Bridging this knowledge gap is critical to tailoring management strategies for this subgroup of patients, who may face unique clinical challenges. This study aimed to compare clinical characteristics, maternal comorbidities, obstetric complications, and pregnancy outcomes among three groups of SLE patients: those without aPL, those with isolated aPL, and those with secondary APS, using data from a multicenter Spanish registry of pregnancies. Methods A multicenter retrospective cohort study included pregnancies in women fulfilling the 2012 SLICC or 2019 ACR/EULAR classification criteria for SLE. Patients were classified into three subgroups: SLE without aPL, SLE with isolated aPL, and SLE with secondary APS. Data were collected at preconception visits, during each trimester, and post-delivery. Key variables included clinical and immunological profiles, maternal comorbidities, obstetric history, pregnancy complications, and delivery outcomes. Comparative analyses were performed to evaluate maternal and fetal outcomes across the subgroups. Results A total of 201 pregnancies were analyzed: 43 in women with SLE without aPL, 31 in women with isolated aPL, and 20 in women with SLE-APS. Pregnancy outcomes differed markedly. Women with SLE-APS experienced the highest rates of adverse outcomes, with complications occurring in 60% of pregnancies, compared with 20% inSLE without aPL and 5% in isolated aPL (p 0.0001). Preterm delivery was significantly more frequent in the APS group (27%) than in those without aPL (14%) or with isolated aPL (6%) (p = 0.04). Likewise, fetal death before 10 weeks affected nearly one-third of pregnancies in SLE-APS (30%), versus 9% and 5% in the other groups, respectively (p = 0.02). Conclusion This multicenter study highlights the increased risk of adverse pregnancyoutcomes in women with SLE-APS, particularly fetal death before 10 weeks and preterm delivery. Although women with isolated aPL also face higher pregnancy risks compared to those without aPL, their outcomes are less severe than those with APS. Disclosure C. Sieiro Santos: None. J. Ordas: None. A. Merino: None. H. Amar Muñoz: None. S. Burger: None. I. Brana: None. R. Blanco: None. V. Taboada: None.
Santos et al. (Wed,) studied this question.