1 Department of Obstetrics and Gynecology, University of Calgary, Calgary, AB.
2 Department of Obstetrics and Gynecology, Red Deer Regional Hospital, Red Deer, AB.
3 Department of Obstetrics and Gynecology, University of Calgary, Calgary, AB; Division of Maternal Fetal Medicine, Departments of Obstetrics and Gynecology and Medical Imaging, Foothills Medical Centre, Calgary, AB.