MMP9 and gestational diabetes: The aim of this work was to study markers of insulin resistance and MMP2 and MMP9 activities in maternal plasma, as well as to evaluate placental morphology, placental levels of collagen, glycogen and lipids, placental expression of proteins and genes involved in the endocytic pathways, and miR-199 levels in the placentas from both control patients and GDM patients treated or not with a diet enriched in three tablespoons of EVOO daily.