MTHFR and Rare hereditary thrombophilia: On the other hand, some researchers have shown no association between inherited thrombophilia and recurrent pregnancy loss [41–45], possibly because either the only evaluated SNP was MTHFR C677T [43, 44] or the sample sizes were small, that is, 40 patients and 20 controls [42] and 55 women with recurrent pregnancy loss and 50 controls [41].