LAUSR

Objective This study aims to analyze factors related to pregnancy outcomes in women with positive antiphospholipid antibodies and previous adverse pregnancy outcomes (APOs) prospectively. Methods Patients’ characteristics were described. Factors associated with obstetric complications were analyzed using logistic regression analysis. Results A total of 128 females with 73.4% non-criteria obstetric antiphospholipid syndrome (NC-OAPS) were included. APOs accounted for 38.3%, of which 65.3% were fetal losses. Live birth rates in criteria OAPS and NC-OAPS were similar (76.5% and 74.5%). For the whole patients, antinuclear antibody (ANA) titer ≥ 1:160 (OR 5.064, 95% CI (1.509, 16.995), P  = 0.009) was a risk factor for APOs and low molecular weight heparin (LMWH) use (OR 0.149, 95% CI (0.029, 0.775), P  = 0.024)) was a protective factor. Age (OR 1.159, 95% CI (1.011, 1.329), P  = 0.034) and previous APOs ≥ 3 times (OR 3.772, 95% CI (1.14, 12.435), P  = 0.029) were risk factors for fetal loss, and LMWH use (OR 0.068, 95% CI (0.009, 0.486), P  = 0.007) was a protective factor. Regular rheumatology visits was a protective factor for APOs and fetal loss (OR 0.085, 95% CI (0.024, 0.306), P  < 0.001; OR 0.019, 95% CI (0.004, 0.104), P  < 0.001). The proportion of it decreased in APOs and fetal loss groups (53.1% and 28.1%). Glucocorticoid use was a risk factor for APOs in NC-OAPS and higher serum C3 levels in the first gestational trimester was a protective factor for fetal loss (OR 3.703, 95% CI (1.402, 9.777), P  = 0.008; OR 0.041, 95% CI (0.002, 0.947), P  = 0.046). Conclusion Age, APO history, ANA titer, LWMH and glucocorticoid use, serum C3 levels, and regular rheumatology visits were related to obstetric complications. Key Points • This was one of the few prospective studies focused on patients with positive antiphospholipid antibodies and previous adverse pregnancy outcomes. The majority were NC-OAPS patients. • The study first evaluated the impact of rheumatologists’ monitoring based on individual disease assessments on pregnancy outcomes. The live birth proportion was similar in patients with criteria OAPS and NC-OAPS when treated. • Age, APO history (≥ 3 times), ANA titer (≥ 1:160), LMWH use, glucocorticoid use, and serum C3 were factors related to obstetric complications.