1. Division of Neurosurgery, Toronto Hospital, University of Toronto, Toronto, Ontario, Canada
2. Department of Obstetrics and Gynaecology, Toronto Hospital, University of Toronto, Toronto, Ontario, Canada
3. St. Michael's Hospital, and Division of Neurosurgery Toronto Hospital, University of Toronto, Toronto, Ontario, Canada
4. Fetal-Maternal Medicine. Obstetrics and Gynecology, Toronto Hospital, University of Toronto, Toronto, Ontario, Canada