Prevalence of antiphospholipid syndrome among women with recurrent pregnancy loss: a cohort study

Abstract Objective: This study aimed to evaluate the prevalence of antiphospholipid syndrome (APS) among women experiencing recurrent pregnancy loss (RPL). Methods: A cross-sectional was conducted, reviewing the medical records of 134 women with a history of two or more miscarriages, treated between January 2014 and May 2024 at a tertiary university center in Belo Horizonte, Brazil. APS screening was performed by assessing anticardiolipin (IgG and IgM), lupus anticoagulant, and anti-β2-glycoprotein-1 (IgG and IgM) antibodies, based on Sapporo criteria. All tests were performed during non-pregnant periods and at least 12 weeks after the last miscarriage. Results: The study included 134 women with a mean age of 33.8 ± 5.7 years. The number of prior miscarriages ranged from 2 to 11 per couple. Among the patients who presented the lupus anticoagulant, only two (1.49%) tested positive in two samples, as per revised Sapporo criteria. Considering IgG and IgM anticardiolipin antibodies, four patients (2.98%) tested positive in two samples according to old Sapporo criteria, with one patient having a positive IgG test in two samples, two having positive IgM in two samples and a single patient having both positive tests. None of the 56 patients tested positive for anti-β2-glycoprotein-1 antibodies in two samples. Conclusion: The prevalence of antiphospholipid antibodies, in line with revised Sapporo criteria, is low among Brazilian women with recurrent pregnancy loss, consistent with recent studies in literature. Ensuring the appropriateness of diagnostic criteria is crucial to avoid unnecessary treatment with platelet anticoagulants and heparin in this population.