1. Department of Obstetrics and Gynecology, University of Calgary, Calgary, AB, Canada
2. Calgary Chronic Pain Centre, Richmond Road Diagnostic and Treatment Centre, Calgary, AB, Canada
3. Department of Obstetrics and Gynecology, Centre Hospitalier de l’Université de Montréal, Montreal, QC, Canada
4. Department of Anesthesia, Providence Healthcare, Vancouver, BC, Canada
5. Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada