Placental infection with SARS-CoV-2, analysis of 16 cases and literature review

PURPOSE: Since December 2019, the whole world has been affected by coronavirus [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]. However, the effects of COVID-19 infection on pregnancy and fetal transmission are still unclear. Therefore, this study was conducted to evaluate placenta samples regarding detection of SARS-CoV-2 RNA in women affected with COVID-19. METHOD: This study was a part of a cohort study carried out on pregnant women with a diagnosis of COVID-19 infection who had been admitted to the Imam Reza Hospital in Mashhad, Iran, from March 20 to August 5, 2020. Clinical and laboratory information of all the patients was collected and chest computed tomography (CT) scans were reviewed. Totally, 16 placental tissue were prepared for real time polymerase chain reaction (RT-PCR) testing. All samples were tested by PowerChek PCR real-time kit (South Korea) with 2 target genes (E gene and Rd Rp gene), and Pishtaz Teb kit, (Iran) with 2 target genes (N gene and RdRp gene). RESULT: In the first RT-PCR kit by PowerChek kit, 6 samples were positive for a single gene (E gene) and 2 samples were positive for both genes (E gene and Rd Rp gene). In the second RT-PCR kit by Pishtaz Teb kit, 3 samples were positive for two genes (N gene and RdRp gene). CONCLUSION: This present study showed that infection of placenta with SARS-CoV-2 may occur in pregnancy. However, whether this infection leads to neonatal infection and serious complication in pregnancy remains unclear.