Maternal obesity and placental pathology in correlation with adverse pregnancy outcome

Maternal obesity is associated with increased maternal and fetal morbidity and mortality, with an increased risk of gestational diabetes mellitus (GDM) and preeclampsia (PE). This prospective study histopathologically analyzes the placentas obtained from 34 pregnant obese women studied between October 2016 and May 2020. The 10 cases of term placentas from obese pregnancies with GDM and the 12 cases with PE were examined by the Hematoxylin-Eosin (HE), Masson's trichrome (MT) and Periodic Acid-Schiff-Hematoxylin (PAS-H) classical stainings, and by the immunohistochemical evaluation and compared to placentae from uncomplicated term obese pregnancies (12 cases). We did not meet placental histopathological (HP) abnormalities that we could classify as characteristic only for the state of obese pregnancy, but we did find placental changes associated with PE and GDM, in the context of obese pregnancy. In the case of association with PE, there were common lesions, manifested by intra- and perivillous fibrinoid deposition, calcification, and placental infarction area, to which were added numerous syncytial knots. In the case of obese pregnancy associated with GDM, we found, in addition to common placental lesions of obesity, intravillositary vascular edema and in the terminal villi appearing chorangiosis. This study revealed a number of HP changes that occur in maternal obesity, even in uncomplicated obese pregnancies. A characteristic of obese pregnancies associated with PE was the presence of numerous syncytial knots, and in obese pregnancies associated with GDM, the most common HP lesion was placental chorangiosis. Certainly, we cannot conclude that these HP lesions are specific to a particular pathology, but they belong primarily to the status of maternal obesity.