The impact of the novel coronavirus infection COVID-19 on the mother-placenta-fetus system
Impaired placental development during early pregnancy associated with systemic damage to the vascular endothelium in patients with COVID-19 may result in a number of complications. The study was aimed to reveal histological and immunohistochemical (IHC) features of placental tissue in pregnant women with COVID-19 at different stages of gestation, and to examine the contribution of those to pathogenesis of the disease involving mother-placenta-fetus system. The following two groups of pregnant women were studied: index group of 66 patients with COVID-19, and comparison group of 40 women with no symptoms of viral infection. Macroscopic and microscopic examination, and the IHC analysis of placental samples were carried out. Clinical and anamnestic characteristics of patients with COVID-19 were analyzed taking into account disease severity, delivery route and perinatal outcome. ICH staining using primary antibody revealed elevated expression of proinflammatory factors (TNFα, IL8) and reduced level of anti-inflammatory factors (IL4) in placental structures of patients with moderate and severe СOVID-19 (р < 0.05). The villous tree rearrangement and the development of subclinical placental insufficiency, which could in some cases be decompensated during labor, resulting in clinical manifestations of acute fetal hypoxia were detected in the placental samples obtained from the index group patients. The obstetrical tactics for mothers with COVID-19 should be decided individually based on the risk factors; continuous cardiotocography should be used during labor. It may be appropriate to conduct IHC analysis of placenta in puerperant women with COVID-19 in order to fine-tune the tactics of neonatal management and to predict possible neonatal complications.