Our results showed a positive correlation between SGA newborns and inherited thrombophilia mutations such as PAI-I deficiency, MTHFR A1298C homozygous, MTHFR C677T homozygous, antithrombin III, and factor V Leiden (r = 0.53), and at the same time a negative correlation with acquired thrombophilia markers such as lupus anticoagulant (r = 0.024). This evidence concerns the gene MTHFR and Rare hereditary thrombophilia.