The World Health Organization (WHO) (who.int, last accessed: 29 July 2023), the International Diabetes Federation (IDF) (idf.org, last accessed: 29 July 2023), the American College of Obstetricians and Gynecologists (ACOG) [129] and the American Diabetes Association (ADA) [130] all recommend that insulin should be the first-line pharmacological therapy in GDM management if lifestyle changes are not sufficient to reach the target glycemic levels. This evidence concerns the gene INS and diabetes mellitus.