XDH and gestational diabetes: The metabolic pathways through which GDM hyperglycemia is able to induce oxidative stress as well as cell and tissue damage are polyol pathway, formation of advanced glycation end products (AGE), activation of protein kinase C (PKC), hexosamine pathway, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, xanthine oxidase, and mitochondrial pathway (Figure 1) [1], which is described below.