Pathomorphological Changes of the Placenta in Antenatal Asphyxia of the Fetus Associated with the Coronavirus Disease (COVID-19) in Pregnant Women

Abstract

Сoronavirus disease (COVID 19) in a pregnant woman remains a risk factor for perinatal losses despite the barrier function of the placenta. This prompted us to do some research. Objective — to determine the pathomorphological changes of the placenta and fetus during antenatal asphyxia in the acute period of COVID-19 in a pregnant woman. Materials and methods. We studied placentas and fetuses in case of antenatal asphyxia (n = 16) in the acute period of the COVID-19 in a pregnant woman, confirmed by a positive PCR test (determination of SARS-CoV-2 RNA). The duration of the post-COVID interval (time from the diagnosis of COVID-19 to delivery) was 1—3 weeks. Results and discussion. Intrauterine death of the fetus occurred at different gestational period: from 26 to 38 weeks (median 33). At the same time, the woman fell ill with COVID-19 between 18 and 35 weeks of gestation (median 31). Hemorrhages in the right atrium and auricle of the heart were observed in fetuses — 93.8 % (95 % CI: 75.4—100); dark blood clots in the chambers of the heart; hemorrhages under the periosteum of the bones of the skull, stasis in the veins of the brain — 81.3 % (95 % CI: 57.1—96.7), hemorrhages in the scrotum, spermatic cord — 6.3 % (95 % CI: 0.0—24.6) and kidney hemorrhages — 62.5 % (95 % CI: 36.2—85.4). When examined macroscopically, the placenta was characterized by a flabby or dense consistency; diffuse hemorrhages or local blood clots in numerous cysts; areas of abruption, thrombosis of umbilical cord vessels. Microscopic examination of the placenta revealed chorioamnionitis — 81.3 % (95 % CI: 57.1—96.7 %), intervillositis — 93.8 % (95 % CI: 75.4—100), acute villitis — 56.3 % (95 % CI: 30.2—80.6). Basal deciduitis was detected in all observations in 100 % (95 % CI: 88.8—100). Disorders of blood circulation were found in the placentas: stasis, thrombosis, hemorrhages; and necrosis of the arteriole endothelium — 100 % (95 % CI: 88.8—100 %). Conclusions. COVID-19 in a pregnant woman from 18 to 35 weeks of gestation (median 31) is a risk factor for perinatal losses. No significant differences were found between the severity of the course of COVID-19 in the mother and the morphological changes of the placenta. Pathognomonic changes in the fetus with COVID-19 in the mother in the acute period: «porphyry lung», hemorrhages in the right atrium, under the periosteum of the bones of the skull, spermatic cord, kidneys, blood clots in the chambers of the heart. The cause of antenatal death of the fetus in the acute period of COVID-19 in a pregnant woman is acute placental insufficiency associated with disorder of placental-fetal blood circulation, due to manifestations of the exudative phase of inflammation: placentitis (focal chorioamnionitis, acute villitis, intervilositis, basal deciduitis) and disorder of blood rheology, which was manifested by thrombosis, hemorrhages in the intervillous space, detachment of the placenta.