SARS-COV2 placentitis and pregnancy outcome: A multicentre experience during the Alpha and early Delta waves of coronavirus pandemic in England.
Sophie Stenton, Jo McPartland, Rajeev Shukla, Kerry Turner, Tamas Marton, Beata Hargitai, Andrew Bamber, Jeremy Pryce, Cesar L Peres, Nadia Burguess, Bart Wagner, Barbara Ciolka, William Simmons, Daniel Hurrell, Thivya Sekar, Corina Moldovan, Claire Trayers, Victoria Bryant, Liina Palm, Marta C Cohen
Author Information
Sophie Stenton: Histopathology Department, Sheffield Children's NHS FT, Sheffield, UK.
Background: Pregnant women with SARS-CoV-2 infection experience higher rates of stillbirth and preterm birth. A unique pattern of chronic histiocytic intervillositis (CHI) and/or massive perivillous fibrin deposition (MPFD) has emerged, coined as SARS-CoV-2 placentitis. Methods: The aim of this study was to describe a cohort of placentas diagnosed with SARS-CoV-2 placentitis during October 2020-March 2021. Cases with a histological diagnosis of SARS-CoV-2 placentitis and confirmatory immunohistochemistry were reported. Maternal demographic data, pregnancy outcomes and placental findings were collected. Findings: 59 mothers delivered 61 infants with SARS-CoV-2 placentitis. The gestational age ranged from 19 to 41 weeks with most cases (78.6%) being third trimester. 30 infants (49.1%) were stillborn or late miscarriages. Obese mothers had higher rates of pregnancy loss when compared with those with a BMI <30 [67% (10/15) versus 41% (14/34)]. 47/59 (797%) mothers had a positive SARS-CoV-2 PCR test either at the time of labour or in the months before, of which 12 (255%) were reported to be asymptomatic. Ten reported only CHI, two cases showed MPFD only and in 48 placentas both CHI and MPFD was described. Interpretation: SARS-CoV2 placentitis is a distinct entity associated with increased risk of pregnancy loss, particularly in the third trimester. Women can be completely asymptomatic and still experience severe placentitis. Unlike 'classical' MPFD, placentas with SARS-CoV-2 are generally normal in size with adequate fetoplacental weight ratios. Further work should establish the significance of the timing of maternal SARS-CoV-2 infection and placentitis, the significance of SARS-CoV2 variants, and rates of vertical transmission associated with this pattern of placental inflammation. Funding: There was not funding associated with this study.
