Ethics approval
Procedures in the study were reviewed and approved by the institutional ethics committee responsible for human experimentation. Ethics Committee name: Royal Women’s Hospital ethics committee (secretariat contact Mr Arthur Hui, Royal Women’s Hospital, Melbourne, Australia); approved 2004; enrolled onto the Perinatal Trials Registry of Australia (PTR 543) and also onto the Australian Clinical Trials Registry (ACTR) Number 12605000709640. The ACTR is an ICMJE acceptable registry and meets the criteria of a WHO Primary registry