1. Placenta Program, Maternal-Fetal Medicine Division, Department of Obstetrics & Gynaecology, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Toronto, ON M5G 1X5, Canada
2. Department of Obstetrics and Gynaecology, University of British Columbia, 4500 Oak Street, Vancouver, BC V6H 2N1, Canada
3. Department of Obstetrics and Gynaecology, University Medical Center of Groningen, CB20, Hanzeplein 1, 9700 RB Groningen, The Netherlands
4. Department of Pathology, Children’s Hospital of Eastern Ontario, Ottawa, ON K1H 8L1, Canada
5. Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
6. Department of Pathology and Laboratory Medicine, Vernon Jubilee Hospital and University of British Columbia, Vancouver, BC V1T 5L2, Canada