title: Tolerance intervals for standards in ultrasound measurements: determination of BPD standards.
abstract: Standards for the relationship between BPD and gestational age are used for the assessment of fetal size. We measured the BPD in 310 women with exact gestational age in a cross-sectional study. Two types of BPD charts were constructed based on tolerance intervals: directly from measurements and after model fitting. We found that the tolerance intervals based on the model are smoother and narrower than those achieved by direct determinations. The fit, advantages, and prospects of the model are discussed.
mesh_terms: D001824:Body Constitution; D003430:Cross-Sectional Studies; D005260:Female; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D008954:Models, Biological; D010296:Parietal Lobe / Q000033:anatomy & histology*; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012016:Reference Values; D013997:Time Factors; D014463:Ultrasonography