Due to this systemic alteration in the presence of hyperglycemia, it is possible to hypothesize that the high serum levels of HtrA1 found in pregnancies complicated by GDM are due to the chronic inflammation that characterizes this pathology, leading to both maternal vascular damage (since HtrA1 is expressed in the endothelial cells of maternal vessels) and placental (since HtrA1 it is expressed by the syncytiotrophoblast, the outer layer of the trophoblast in contact with the maternal blood present in the intervillous space and, therefore, with the cytokines contained therein). This evidence concerns the gene HTRA1 and gestational diabetes.