Do Serologic Domains of the 2023 ACR/EULAR Classification Criteria for Antiphospholipid Syndrome Define Distinct Clinical Subgroups During Pregnancy?

To evaluate the clinical applicability of the 2023 ACR/EULAR serologic classification criteria for antiphospholipid syndrome (APS) in a cohort of pregnant women across the APS spectrum, and to assess the association between serologic burden and clinical manifestations, obstetric outcomes, and treatment response, a retrospective cohort study was conducted including 190 pregnant women with persistent antiphospholipid antibody (aPL) positivity. Patients were classified according to the ACR/EULAR serologic criteria into two groups: high serologic burden (≥3 points) and low serologic burden (≤2 points). Clinical, obstetric, therapeutic, and reproductive variables were compared between groups. Nearly one-third of women did not meet the 2023 ACR/EULAR serologic threshold. Although most patients with thrombotic or obstetric APS fulfilled the ACR/EULAR serologic threshold, 28% of women with obstetric APS and 35.3% of those with pregnancy-related morbidity had ≤2 serologic points. Baseline demographic characteristics were similar between groups. Obesity (23.9% vs. 10%;