A preliminary study of placentas referred to Barts Health Histopathology during the second Covid wave in London has found an increased frequency of a rare lesion, usually reported in <1% of pregnancies. Massive perivillous fibrin deposition (MPFD) causes placental insufficiency, leading to poor pregnancy outcomes, including severe intrauterine growth restriction and stillbirth. Of 224 placentas referred in December 2020 and January 2021, 11 (5%) cases of MPFD were identified. No cases had been identified in the same months in the previous year, and only one in the comparable period in the year prior to that. Of 33 placentas investigated, 30 were from COVID-19 positive mothers, 11 with MPFD. All 11 placentas with MPFD were Covid positive, and of these six were successfully sequenced and found to be positive for the alpha variant. Co-author Matina Iliodromiti said that the observed increase in MPFD cases during the alpha wave of the pandemic and these histopathological results suggest that Covid can cause MPFD, but that further studies are needed to confirm this finding.
Esin Kotiloglu-Karaa, Beatrix Kele, Raghavendran Kulasegaran-Shylini, Claire E Broad, Dola Owoyemi, Joanne Martin, Graham MacPhail, Stamatina Iliodromiti, Anna Riddell, Eliza Alexander, Teresa Cutino-Moguel. SARS-CoV-2 placental infection is associated with massive perivillous fibrin deposition at the maternal-fetal interface: a preliminary study. Clinical Infectious Diseases 2022