The length of a fetus's ear may be an indicator of aneuploidy, especially when other sonographically detectable structural abnormalities are present.
Parameters:
(1) vertical length of the ear in mm
(2) gestational age in weeks
(3) 10th percentile for ear length for a gestational age and ethnic group (approximately 1.3 standard deviations below the mean)
(4) biparietal diameter in mm
biparietal diameter to ear length ratio =
= (biparietal diameter in mm) / (ear length in mm)
Criteria for aneuploidy:
(1) length of the ear <=10th percentile
(2) biparietal diameter to ear length ratio >= 4
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Specialty: Obstetrics & Gynecology, Pedatrics, Genetics
ICD-10: ,
