title: Letter to the editor.
authors.affiliation: Women's and Children's Health, University of New South Wales, Sydney, Australia, WILLIAM.LEDGER@SESIAHS.HEALTH.NSW.GOV.AU.
authors.forename: William
authors.initials: W
authors.lastname: Ledger
mesh_terms: D006801:Humans; D015201:Meta-Analysis as Topic; D059008:Time-Lapse Imaging / Q000379:methods*