1 Department of Women's & Obstetric Anesthesia, IWK Health Centre, Dalhousie University, 5850/5980 University Avenue, P.O. Box 9700, Halifax, NS, B3K 6R8, Canada.
2 Department of Women's & Obstetric Anesthesia, IWK Health Centre, Dalhousie University, 5850/5980 University Avenue, P.O. Box 9700, Halifax, NS, B3K 6R8, Canada. D.McKeen@Dal.Ca.