Mothers treated with metformin for the management of GDM have been shown to have reduced gestational weight gain and less risk of gestational hypertension than those on insulin or glyburide regimens, and their offspring have a lower risk of hypoglycemia, a lower risk of macrosomia (i.e., neonatal birthweight > 4000 g), and a shorter stay in the neonatal intensive care unit (NICU), especially in the case of comparisons with glyburide [79,80]. This evidence concerns the gene INS and gestational diabetes.