title: Humerus length measurement in Down syndrome screening.
abstract: OBJECTIVE
  To compare the predictive values of different humeral shortness assessment methods in Down syndrome screening.
  
  
  METHODS
  674 high-risk singleton pregnancies with a valid last menstrual period (LMP) date were studied. Nomogram and formulas were derived from a subset of the studied group. Sensitivities of fifth percentile and cut-off values of 0.9 for observed-to-expected (obs/exp) humerus length (HL) ratio according to biparietal diameter (BPD) and gestational age (GA) were compared.
  
  
  RESULTS
  Sensitivities were 20%, 46.7% and 60% for the 5th percentile, a cut-off value of 0.9 for obs/exp HL by BPD and a cut-off value of 0.9 for obs/exp HL by GA, respectively.
  
  
  CONCLUSIONS
  Using gestational age instead of BPD when calculating expected humeral length may increase the predictive role of humeral shortness in Down syndrome screening of pregnant women with valid and correct LMP.
authors.affiliation: Obstetrics and Gynecology Department, University of Istanbul, School of Medicine, Topkapi/Istanbul, Turkey.
authors.forename: I H
authors.initials: IH
authors.lastname: Kalelioğlu
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D004314:Down Syndrome / Q000000981:diagnostic imaging* / Q000453:epidemiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging*; D008403:Mass Screening; D008875:Middle Aged; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal