One study has suggested that insulin resistance in gestational diabetes could be improved by the administration of inositol, as in polycystic ovary syndrome,14 and several studies have shown that myo-inositol supplementation increases the action of endogenous insulin.10,11,15,16 These studies imply that myo-inositol supplementation can be used therapeutically to prevent GDM. This evidence concerns the gene INS and polycystic ovary syndrome.