1. McMaster University; Department of Obstetrics and Gynecology; 1200 Main Street West MDCL 2215 Hamilton ON Canada L8N 3Z5
2. Frere Hospital, Walter Sisulu University, University of the Witwatersrand, Eastern Cape Department of Health; Department of Obstetrics and Gynaecology; East London South Africa
3. The University of Liverpool; Cochrane Pregnancy and Childbirth Group, Department of Women's and Children's Health; First Floor, Liverpool Women's NHS Foundation Trust Crown Street Liverpool UK L8 7SS