Pregnant women with COVID-19: the placental involvement and consequences.

SARS-CoV-2, the leading cause of COVID-19 pandemic, was detected for the first time in Wuhan. In this study, we investigated the potential undesirable maternal and feto-neonatal consequences of COVID-19, and the related pathophysiological alterations in mother, neonate, and especially in the placenta as a vital organ, were reviewed. Also, the possibility of vertical transmission of virus and placental abnormalities were evaluated. The pregnant women were a vulnerable population for COVID-19, and several obstetric consequences were reported following SARS-CoV-2 infection. The higher risk of abruption, preterm labor, maternal death, stillbirth, intrauterine growth restriction, and newborns with fetal distress were adverse pregnancy and perinatal outcomes of COVID-19. Despite the ACE2 expression on placental components was confirmed, there is no agreement on the mother-child vertical transmission of this virus. Therefore, feto-neonatal consequences might be associated with placental abnormalities. The placental abnormalities are characterized by feto-maternal vascular malperfusion. Additionally, these adverse consequences lead to early termination of pregnancy in some cases, mostly via cesarean section. The pregnant women screening, coordination between healthcare personnel and neonatal unit, and infected women quarantine may decrease the risk of maternal and neonatal death after delivery.