title: Calculation of unconditional and conditional reference intervals for foetal size and growth from longitudinal measurements.
abstract: Methods for estimating unconditional and conditional reference intervals for foetal size and growth based on longitudinal observations are presented. The methods are based on simple random-effects regression models and involve transforming both the response and the covariate (timepoint). A dataset from a designed longitudinal study of foetal size is analysed in detail as a motivating example.
mesh_terms: D000886:Anthropometry; D003627:Data Interpretation, Statistical; D005314:Embryonic and Fetal Development; D005260:Female; D005865:Gestational Age; D006801:Humans; D008137:Longitudinal Studies; D015233:Models, Statistical; D015999:Multivariate Analysis; D011247:Pregnancy; D012016:Reference Values; D012044:Regression Analysis; D012107:Research Design; D016216:Ultrasonography, Prenatal