Maternal insulin does not cross the placental structures, and foetal beta islets are not developed to produce insulin until 12th week of gestation where early hyperglycemias can lead to congenital malformations and miscarriages, something that is two or three times more likely among patients with type 1 and type 2 diabetes than in healthy pregnancies [41]. This evidence concerns the gene INS and type 2 diabetes mellitus.