Rebecca N. Baergen, MDProfessor of Pathology and Laboratory MedicineChief of Obstetric and Perinatal PathologyNew York Presbyterian Hospital - Weill Cornell MedicineDepartment of Pathology and Laboratory MedicineNew York, NYUSAGraham J. Burton, MD, DScProfessor EmeritusCentre for Trophoblast ResearchUniversity of CambridgeCambridge, UKCynthia G. Kaplan, MDProfessor Emeritus of PathologyState University of New YorkStony Brook, NYUSA