SERPINB2 and endothelial dysfunction: Potential etiological factors included in early pregnancy loss in women with PCOS other than the already mentioned hypersecretion of luteinizing hormone, hyperinsulinemia and hyperandrogenaemia include altered endometrial receptivity, abnormalities in plasminogen activator inhibitor (PAI) activity and abnormal vascular responses due to endothelial dysfunction [63,64].