Prevalence of antiphospholipid antibodies and risk of subsequent adverse obstetric outcomes in women with prior pregnancy loss

• Prevalence of aPL in women with a history of REM but not SLE or VTE is low.
• Among these women, pregnancy outcomes are generally favorable and uncomplicated.
• Patients with SLE and/or VTE are at increased risk of adverse obstetric outcomes.

The reported prevalence of antiphospholipid antibodies in women with a chief complaint of pregnancy loss varies, as does the risk of adverse outcomes in subsequent pregnancies. Our objectives were to assess the prevalence of antiphospholipid antibodies meeting revised Sapporo thresholds among women presenting with a chief complaint of pregnancy loss and risks in subsequent pregnancies for these women. We examined a retrospective cohort of patients presenting with a chief complaint of pregnancy loss between 2003 and 2012. Antiphospholipid antibodies were assessed at the providers’ discretion, and patients were considered positive if they met the revised Sapporo criteria. Patient data were obtained by review of the medical records. 338/390 women (86.7%) presented with a chief complaint of pregnancy loss and had testing for antiphospholipid antibodies. 19/338 women (5.6%) persistently tested positive for at least one antiphospholipid antibody. Seven women who tested positive had isolated recurrent early pregnancy loss ≤10 weeks, and 12 women who tested positive had venous thromboembolism (VTE), systemic lupus erythematosus (SLE), delivery <34 weeks for pre-eclampsia, and/or placental insufficiency, or fetal demise >10 weeks. Subsequent pregnancy outcomes were available for 13 patients. Compared with women with recurrent early pregnancy loss alone, subsequent obstetric morbidity was significantly more likely in those patients with a history of SLE and/or VTE (p = 0.048). We conclude that the prevalence of positive antiphospholipid antibodies in women with a chief complaint of pregnancy loss and without autoimmune disease or prior thrombosis is low and that among these women, subsequent pregnancy outcomes are largely favorable.