Ultrasonographic measurements of fetal ear.
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.
Shimizu
T
T
Department of Obstetrics and Gynecology, Ottawa General Hospital, Ontario, Canada.
Salvador
L
L
Allanson
J
J
Hughes-Benzie
R
R
Nimrod
C
C
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