title: Rejoinder.
authors.affiliation: School of Nursing and Midwifery, University of Newcastle, NSW, Australia and Australian Institute of Health and Welfare National Perinatal Statistics Unit, University of New South Wales, NSW, Australia.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Fahy
authors.forename: Sally K
authors.initials: SK
authors.lastname: Tracy