Women with antiphospholipid syndrome (APS) and antiphospholipid antibodies (aPL) are at a high risk of recurrent spontaneous miscarriages and late pregnancy complications. The prevalence of obstetric complications in aPL positive women is about 15-20%. The APS is defined by the combination of a clinical venous or arterial thrombotic event or a pregnancy complication and the laboratory detection of aPL. Adverse obstetric events include: recurrent miscarriages, late loss or early delivery due to preeclampsia or placental insufficiency. Although many of the clinical manifestations of the APS can be related to thrombotic events other non-thrombotic mechanisms have been proposed to explain the obstetrical manifestations. Though heparin and aspirin are indicated for the treatment of recurrent pregnancy loss, there is a paucity of randomized trials in this area. The therapeutic management of other obstetric complications, such as preeclampsia and intrauterine growth restriction need to be confirmed. New therapies for the prevention and the treatment of obstetric complication are being investigated in experimental models. This review will discuss of what we have learned regarding pregnancy morbidity and APS.