This document reflects emerging clinical and scientific advances on the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed. Local institutions can dictate amendments to these opinions. They should be well documented if modified at the local level. None of these contents may be reproduced in any form without prior written permission of the SOGC. This clinical practice guideline review has been prepared by Clinical Practice Obstetrics Committee and approved by the Executive and Board of the Society of Obstetricians and Gynaecologists of Canada.