Pregnancy outcome in different clinical phenotypes of antiphospholipid syndrome

Women with antiphospholipid syndrome (APS) may have diverse pregnancy outcomes. The objective of this study was to evaluate pregnancy outcome in women with APS according to their clinical phenotype, i.e. thrombotic and obstetric APS. Eighty-three pregnancies in 67 women with APS were included in the study, including 21 with recurrent miscarriage (Group 1), 21 with late fetal loss or early delivery due to placental dysfunction (Group 2) and 41 with thrombotic APS (Group 3). Group 3 had higher rates of preterm delivery (26.8% versus 4.7%, p = 0.05) than Group 1 and more small for gestational age (SGA) babies than Group 2 (39.5% versus 4.8%, p = 0.003). Group 2 had significantly longer gestations compared with their pretreatment pregnancies (38.4 [28.4-41.4] versus 24.0 [18-35] weeks, p < 0.0001) and 100% live birth rate after treatment with aspirin and low-molecular-weight heparin (LMWH). In conclusion, women with thrombotic APS (Group 3) have higher rates of pregnancy complications than those with obstetric APS (Groups 1 and 2). Treatment with aspirin and LMWH is associated with improved outcomes for women with previous late fetal loss or early delivery due to placental dysfunction (Group 2).