Antiphospholipid syndrome (APS) is a rare systemic autoimmune disease, the obstetric features of which include recurrent early miscarriage, fetal death at or beyond 10 weeks of gestation, and early delivery for severe preeclampsia or placental insufficiency. Controversies regarding the specificity of these obstetric clinical features, as well as the laboratory diagnostic criteria, are the subject of current debate and reanalysis. Clinical and laboratory features can be used to stratify women with APS in terms of risk of adverse second and third trimester pregnancy outcomes. Numerous “treatments” have been used in high-risk and refractory patients, but rigorously designed clinical trials are needed. APS is a rare disease that requires innovative investigative approaches to provide credible results.