Upregulation of placental inflammatory cytokines, oxidative stress-related genetic variants (myeloperoxidase G-463 A, CYBA C242T, CYP2E1 C-1054T, etc.), glycation and oxidation of proteins caused by hyperglycemia were associated with unfavourable metabolic profiles, insulin resistance, increased oxidative stress, and state of chronic inflammation in patients with GDM, which might increase the risk of adverse perinatal outcomes [6, 8, 11, 20, 21, 47]. This evidence concerns the gene MPO and gestational diabetes.