Sonographic Measurement of Fetal Ear Length in Turkish Women with a Normal Pregnancy

Öz

Abstract

Background: Abnormal fetal ear length is a feature of chromosomal disorders. Fetal ear length measurement is a simple measurement that can be obtained during ultrasonographic examinations. Aims: To develop a nomogram for fetal ear length measurements in our population and investigate the correlation between fetal ear length, gestational age, and other standard fetal biometric measurements. Study Design: Cohort study. Methods: Ear lengths of the fetuses were measured in normal singleton pregnancies. The relationship between gestational age and fetal ear length in millimetres was analysed by simple linear regression. In addition, the correlation of fetal ear length measurements with biparietal diameter, head circumference, abdominal circumference, and femur length were evaluated.Ear length measurements were obtained from fetuses in 389 normal singleton pregnancies ranging between 16 and 28 weeks of gestation.Results: A nomogram was developed by linear regression analysis of the parameters ear length and gestational age. Fetal ear length (mm) = y = (1.348 X gestational age)-12.265), where gestational ages is in weeks. A high correlation was found between fetal ear length and gestational age, and a significant correlation was also found between fetal ear length and the biparietal diameter (r=0.962; p<0.001). Similar correlations were found between fetal ear length and head circumference, and fetal ear length and femur length. Conclusion: The results of this study provide a nomogram for fetal ear length. The study also demonstrates the relationship between ear length and other biometric measurements

Keywords

• Chromosomal disorders, fetal ear length, sonography

References

1. 1. Aase JM, Wilson AC, Smith DW. Small ear in Down’s syndrome: A helpful diagnostic aid. J Pediatr 1973;82:845-7.[CrossRef]
2. 2. Lettieri L, Rodis JF, Vintzileos AM, Feeney L, Ciarleglio L, Craffey A. Ear length in second-trimester aneuploid fetuses. Obstet Gynecol 1993;81:57-60.
3. 3. Nyberg DA, Kramer D, Resta RG, Kapur R, Mahony BS, Luthy DA, et al. Prenatal sonographic findings of trisomy 18: Review of 47 cases. J Ultrasound Med 1993;12:103-13.
4. 4. Awward JT, Azar GB, Karam KS, Nicolaides KH. Ear length: A potential sonographic marker for Down syndrome. Int J Gynecol Obstet 1994;44:233-8.[CrossRef]
5. 5. Chitkara U, Lee L, Oehlert JW, Bloch DA, Holbrook RH, El-Sayed YY, et al. Fetal ear length measurement: a useful predictor of aneuploidy? Ultrasound Obstet Gynecol 2002;19:131-5.[CrossRef]
6. 6. Shimizu T, Salvador L, Allanson J, Hughes-Benzie R, Nimrod C. Ultrasonographic measurement of fetal ear. Obstet Gynecol 1992;80:381-4.
7. 7. Nicolaides K, Shawwa L, Brizot N,Sijders R. Ultrasonographically detectable markers of fetal chromosoml defects . Ultrasound Obstet Gynecol 1993;3:56-69.[CrossRef]
8. 8. Birnholz JC, Farrell EE. Fetal ear length. Pediatrics 1988;81:555-8.

9. 9. Lettieri L, Rodis JF, Vintzileos AM, Feeney L, Ciarleglio L, Craffey A. Ear length in second-trimester aneuploid fetuses. Obstet Gynecol 1993;81:57-60.
10. 10. Yeo L, Guanan ER, Day-Salvatore DL, Vintzileos AM, Walres C. Prenatal detection of fetal aneuploidy using sonographic ear length. Am J Obstet Gynecol 1998:178:141.
11. 11. Yeo L, Guzman ER, Ananth CV, Walters C, Salvatore DD, Vintzileos AM. Prenatal detection of fetal aneuploidy by sonographic ear length. J Ultrasound Med 2003;22:565-76.
12. 12. Shimizu T, Salvador L, Hughes-Benzie R, Dawson L, Nimrod C, Allanson J. The role of reduced ear size in the prenatal detection of chromosomal abnormalities. Prenat Diagn 1997;17:545-9.[CrossRef]
13. 13. Sivan Y, Merlob P, Reisner SH. Assessment of ear length and low set ears in newborn infants. J Med Genet 1983;20:213-5.[CrossRef]
14. 14. Kurjak A,Kirkinen P.Ultrasonographic growth patterns of fetuses with chromosomal aberrarions. Acta Obs Gynecol Scand 1982:61:223-5. [CrossRef]
15. 15. Hutchinson JC Jr, Caldarelli DD, Gould HJ. Classification and multidisciplinary management of microtia. Otolaryngol Clin North Am 1981;14:855-87.
16. 16. Allanson JE, O’Hara P, Farkas LG, Nair RC. Anthropometric craniofacial pattern profiles in Down syndrome. Am J Med Genet 1983:20: 213-5.
17. 17. Chitkara U, Lee L, El-Sayed YY, Holbrook RH, Bloch DA, Oehlert JW, et al. Ultrasonographic ear length measurement in normal second- and thirdtrimester fetuses. Am J Obstet Gynecol 2000;183:230-4. [CrossRef]
18. 18. Joshi KS,Chawla CD, Karki S, Shrestsa NC. Sonographic measurement of fetal pinna length in normal Pregnancies. Kathmandu Univ Med J (KUMJ) 2011;9:49-53.