title: Ultrasonographic measurements of fetal ear.
abstract: OBJECTIVE
  To establish nomograms of fetal ear measurements. Newborns with trisomies have smaller ears than the normal population. This observation led us to believe that ear measurements might be useful in the antenatal prediction of fetuses with abnormal karyotypes.
  
  
  METHODS
  Fetal ear length and width were obtained ultrasonographically in 124 normal singleton pregnancies between 18-42 weeks' gestation. Regression analyses were used to create the nomograms.
  
  
  RESULTS
  Linear relationships were found between ear length and width and gestational age (r = 0.956 and 0.898, respectively). In addition, there were significant correlations between ear measurements and biparietal diameter, head circumference, abdominal circumference, and femur length. The ear width-length ratio and the biparietal diameter-ear length ratio were independent of gestational age.
  
  
  CONCLUSIONS
  These normative data may be helpful in the antenatal prediction of chromosomal abnormalities.
authors.affiliation: Department of Obstetrics and Gynecology, Ottawa General Hospital, Ontario, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Shimizu
authors.forename: L
authors.initials: L
authors.lastname: Salvador
authors.forename: J
authors.initials: J
authors.lastname: Allanson
authors.forename: R
authors.initials: R
authors.lastname: Hughes-Benzie
authors.forename: C
authors.initials: C
authors.lastname: Nimrod
mesh_terms: D004314:Down Syndrome / Q000000981:diagnostic imaging; D004431:Ear, External / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000196:embryology*; D005314:Embryonic and Fetal Development; D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D012016:Reference Values; D016216:Ultrasonography, Prenatal