Pregnancy Outcomes in Non-Criteria Obstetric Antiphospholipid Syndrome: Analysis of a Cohort of 91 Patients

<b>Background</b>: The clinical and laboratory features of patients with non-criteria obstetric antiphospholipid syndrome (NC-OAPS), as well as their pregnancy outcomes and ideal treatment are not clearly determined. The aim of this study is to describe the characteristics and outcomes of pregnancies in NC-OAPS and compare them with an obstetric APS (OAPS) cohort. <b>Methods</b>: This is a retrospective study conducted on a cohort of women referred to a high-risk obstetric unit of a tertiary hospital. Women that were classified as having OAPS or NC-OAPS were included and compared in terms of clinical and laboratory characteristics, management, and subsequent pregnancy outcomes. <b>Results</b>: We identified 107 women with 143 pregnancies, 91 with NC-OAPS and 16 with OAPS. There were no differences in demographic features between both groups. Women with NC-OAPS were more likely to have recurrent implantation failure and were predominantly positive for a single antiphospholipid antibody (aPL) subtype. Both groups were treated similarly (low dose aspirin plus low molecular weight heparin in 87.4% of NC-OAPS and 83.3% of OAPS, <i>p</i> > 0.05). Live birth rate (82.4% and 75.0%, respectively, <i>p</i> > 0.05) and adverse pregnancy outcomes (31.6% vs. 37.5%, <i>p</i> > 0.05) in subsequent pregnancies during follow-up were also similar between groups. <b>Conclusions</b>: This study revealed differences in the previous pregnancy morbidity and aPL profiles in women with NC-OAPS and OAPS, although the therapeutic approach and the outcomes of subsequent pregnancies were similar in both groups.