A 2013 randomized trial of metformin vs. insulin in the management of GDM (23) including 97 pregnancy patients with GDM assigned to receive insulin (n = 47) or metformin (n = 47) showed lower weight gain (p = 0.002) and, moreover, a lower incidence of neonatal hypoglycemia (p = 0.032) in the metformin arm even if 26% of the metformin arm required an addition of insulin to their therapy. This evidence concerns the gene INS and Hypoglycemia.