[1] Univ Alberta, Dept Obstet & Gynecol, Edmonton, AB, Canada
[2] Univ Toronto, Dept Family & Community Med, Toronto, ON, Canada
[3] Mt Sinai Hosp, Ray D Wolfe Dept Family Med, Toronto, ON, Canada
[4] Alberta Hlth Serv, Populat Publ & Aboriginal Hlth, Edmonton, AB, Canada
[5] Univ Manitoba, Coll Nursing, Fac Hlth Sci, Winnipeg, MB, Canada
[6] Univ Alberta, Fac Nursing, Edmonton, AB, Canada
[7] McMaster Univ, Dept Obstet & Gynecol, Radiol, Hamilton, ON, Canada
[8] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON, Canada
[9] Univ Alberta, Div Gastroenterol, Edmonton, AB, Canada
[10] Univ New South Wales, Sch Psychiat, St John God Chair Perinatal & Womens Mental Hlth, Sydney, NSW, Australia