1 Elizabeth Garrett Anderson Institute for Women's Health, Department of Maternal and Fetal Medicine, University College London, London, UK. Electronic address: e.cornish@ucl.ac.uk.
2 Department of Pathology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands; Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: l.vandermeeren@erasmusmc.nl.
3 Department of Obstetrics and Gynecology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: m.l.p.van_der_hoorn@lumc.nl.
4 Department of Obstetrics and Gynecology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands. Electronic address: s.schoenmakers@erasmusmc.nl.
5 Division of Obstetrics and Gynecology, "Antoine Béclère" Hospital, Paris Saclay University Hospitals, Assistance Publique-Hôpitaux de Paris, Clamart, France; Groupe de Recherche sur les Infections pendant la Grossesse (GRIG), Paris, France. Electronic address: alexandre.vivanti@aphp.fr.
6 Division of Obstetrics and Gynecology, "Antoine Béclère" Hospital, Paris Saclay University Hospitals, Assistance Publique-Hôpitaux de Paris, Clamart, France; Groupe de Recherche sur les Infections pendant la Grossesse (GRIG), Paris, France. Electronic address: alexandra.benachi@aphp.fr.
7 Elizabeth Garrett Anderson Institute for Women's Health, Department of Maternal and Fetal Medicine, University College London, London, UK. Electronic address: melissawhitten@nhs.net.
8 Patient Advocate and Founder, COVID-19 and Pregnancy Baby Loss Support Forum, Liverpool, UK. Electronic address: stephanie.hignett@merseycare.nhs.uk.
9 Department of Inflammation, Division of Medicine, University College London, London, UK. Electronic address: thomas.mcdonnell.11@ucl.ac.uk.
10 Elizabeth Garrett Anderson Institute for Women's Health, Department of Maternal and Fetal Medicine, University College London, London, UK. Electronic address: d.j.williams@ucl.ac.uk.