title: How to construct 'normal ranges' for fetal variables.
abstract: A method to estimate reference intervals which depend on gestational age is described. The approach is based on standard statistical techniques, so implementation should be straightforward with most statistical packages. The reference limits are defined by simple formulae which may be plotted as smooth curves. The method is illustrated with analyses of three real datasets arising from different aspects of fetal monitoring.
authors.affiliation: Department of Medical Statistics and Evaluation, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
authors.forename: P
authors.initials: P
authors.lastname: Royston
authors.forename: E M
authors.initials: EM
authors.lastname: Wright
mesh_terms: D002508:Cephalometry; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007668:Kidney / Q000196:embryology; D015233:Models, Statistical; D016011:Normal Distribution; D012016:Reference Values; D012044:Regression Analysis; D016216:Ultrasonography, Prenatal
chemical_list: D006454:Hemoglobins