Evidence of vertical transmission of SARS-CoV-2 and interstitial pneumonia in second-trimester twin stillbirth in asymptomatic woman. Case report and review of the literature

Abstract

Data on the vertical transmission rate of COVID-19 in pregnancy are limited, although data reporting mother-fetal transmission in the second trimester of pregnancy are controversial. We described a case of second-trimester twin stillbirth in a woman with SARS-CoV-2 infection in which placental and fetal markers of infection were detected, despite the absence of respiratory syndrome. The patient developed clinical chorioamnionitis and spontaneously delivered 2 stillborn infants. Placental histology and immunohistochemistry demonstrated SARS-CoV-2 infection mostly within the syncytiotrophoblast, and fetal autopsy showed the development of interstitial pneumonia. Our findings demonstrated that in utero vertical transmission is possible in asymptomatic pregnant women with SARS-CoV-2 infection and that infection can lead to severe morbidity in the second trimester of pregnancy.

Figure

Histology, immunohistochemistry, in-situ hybridation on placenta and fetal lungs Representative pictures of the placenta showing chronic histiocytic intervillositis with accumulation of mononuclear inflammatory cells in the intervillous space (A and C). The fetal lungs in the canalicular stage showed features of interstitial pneumonia with presence of neutrophilic infiltrate and cell debris in the alveolar ducts with increased histiocytic infiltrate (B and D). The placenta showing in situ hybridization (RNAscope Technology) for SARS-CoV-2 spike protein viral RNA (brown dots), resulting in positivity within the syncytiotrophoblast of multiple chorionic villi (E). IHC expression of SARS-CoV-2 NC protein in the chorionic villi resulting in a pattern of circumferential villous staining (G). Tissues from the lungs at the canalicular stage of the first fetus showed an expression of both SARS-CoV-2 spike protein viral RNA (brown dots, RNAscope) and SARS-CoV-2 NC (IHC) (F and H). Original magnification: all × 40. IHC, immunohistochemical; NC, nucleocapsid.