The underlying mechanisms of PCOS-related miscarriages are still not fully understood; however, tonic LH, hyperinsulinemia, hyperandrogenism, low glycodelin levels in endometrium, hypofibrinolysis mediated by increased plasminogen activator inhibitor (PAI) activity could be involved either alone or in combination in the pathogenesis [39,40]. This evidence concerns the gene SERPINB2 and hyperinsulinism.