OBJECTIVE: To test the hypothesis that small ears have diagnostic value in detecting second-trimester aneuploid fetuses by ultrasound. METHODS: We prospectively studied 452 patients with singleton pregnancies undergoing ultrasound examination for genetic amniocentesis at 14-25 weeks and an additional 30 singleton pregnancies at 20-25 weeks with a negative anomaly screen. Standard fetal biometry measurements were obtained, including ear length (from helix to end of lobe). RESULTS: Of these patients, 424 (88%) had ear measurements obtained, and a nomogram for ear length by gestational age was compiled. The relationship between ear length and gestational age was linear across the second trimester (r = 0.84, P < .001). Fourteen fetuses had aneuploidy by amniocentesis, of whom ten had ear lengths at or below the tenth percentile. The sensitivity was 71% and the specificity 92% (377 of 410). Positive and negative predictive values were 23% (ten of 43) and 99% (377 of 381), respectively. CONCLUSION: Fetal ear length may be useful in identifying aneuploid fetuses sonographically during the second trimester.
OBJECTIVE: To test the hypothesis that small ears have diagnostic value in detecting second-trimester aneuploid fetuses by ultrasound. METHODS: We prospectively studied 452 patients with singleton pregnancies undergoing ultrasound examination for genetic amniocentesis at 14-25 weeks and an additional 30 singleton pregnancies at 20-25 weeks with a negative anomaly screen. Standard fetal biometry measurements were obtained, including ear length (from helix to end of lobe). RESULTS: Of these patients, 424 (88%) had ear measurements obtained, and a nomogram for ear length by gestational age was compiled. The relationship between ear length and gestational age was linear across the second trimester (r = 0.84, P < .001). Fourteen fetuses had aneuploidy by amniocentesis, of whom ten had ear lengths at or below the tenth percentile. The sensitivity was 71% and the specificity 92% (377 of 410). Positive and negative predictive values were 23% (ten of 43) and 99% (377 of 381), respectively. CONCLUSION: Fetal ear length may be useful in identifying aneuploid fetuses sonographically during the second trimester.
Authors: Andrea Milic; Susan Blaser; Ashley Robinson; Sandra Viero; William Halliday; Elizabeth Winsor; Ants Toi; Micki Thomas; David Chitayat Journal: Pediatr Radiol Date: 2006-04-25