Gestational diabetes mellitus (GDM) and gestational hypertension (GH) are some of the most common medical conditions associated with pregnancy. These can be correlated with placental morphopathological changes and implicitly can influence good fetal development. The age and weight of the mother can be correlated directly proportionally with those of the fetus but also with histoarchitecture and placental vascularization. The placental appearance associated with GDM and GH reveals macroscopic features, such as calcifications, fibrin deposits and placental infarcts, but the most relevant pathological features are the microscopic ones, highlighted by the classical staining techniques: Hematoxylin-Eosin (HE), Periodic Acid-Schiff (PAS)-Hematoxylin and Masson's trichrome (MT), but also by immunohistochemical technique with the help of the anti-cluster of differentiation 34 (CD34) antibody that labeled the capital endothelium in the structure of the placental terminal villi and thus we were able to quantify the vascular density according to the associated medical pathology. The microscopic changes identified were represented by intravillous and extravillous fibrin depositions, massive placental infarctions caused by vascular suppression due to various causes, such as thrombosis, but also placental calcifications. All these macroscopic and microscopic morphopathological changes, together with the clinical data of the mother and the newborn, we have demonstrated that they are interconnected and that they can vary depending on the pathology, GH or GDM.