Commentary

This case demonstrates the morbidity and mortality that can occur during pregnancy in patients with antiphospholipid syndrome (APS). Despite growing knowledge, consensus on the etiology of recurrent pregnancy loss (RPL) in APS, as well as management, remains controversial. Antiphospholipid antibodies are a heterogeneous group of autoantibodies directed against anionic phospholipids and associated proteins. Their presence can clinically manifest as venous or arterial thrombosis in any tissue or organ or in RPL. The pathogenesis of RPL remains elusive; however, evidence supports a thrombotic etiology. Annexin V, a potent anticoagulant that displaces phospholipid-dependent coagulation factors, is located on placental trophoblast cells and vascular endothelium. One study found a reduction in the concentration of annexin V on cultured trophoblasts as well as vascular endothelial cells in the presence of antiphospholipid antibodies (1). Exposure to antiphospholipid antibodies was also associated with shorter plasma coagulation times in the same study. These findings support the hypothesis that RPL in APS patients could be related to vascular thrombosis. The management of APS patients during pregnancy is focused on preventing vascular thrombosis with antithrombotic agents to reduce maternal morbidity and mitigate the risk of fetal loss. Systematic review and metaanalysis show that treatment with the combination of unfractionated heparin (UFH) and aspirin could reduce the risk of pregnancy loss (relative risk, 0.46; 95% CI, 0.29–0.71) compared to aspirin alone, although the level of evidence was modest. Low-molecular-weight heparin (LMWH) has also shown similar benefits (2). Therefore, current expert consensus supports the combination of aspirin and prophylactic doses of subcutaneous UFH (5000–10000 U every 12 h) or LMWH (i.e., enoxaparin 1 mg/kg or 40–80 mg, dalteparin 5000 U, or nadroparin 3800 U daily) throughout pregnancy for patients with APS associated RPL. Further studies are needed to optimize the treatments for patients with APS.