Nasal-bone length in euploid fetuses at 16–24 weeks' gestation by three-dimensional ultrasound
Article first published online: 12 JUL 2010
Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound in Obstetrics & Gynecology
Volume 36, Issue 3, pages 285–290, September 2010
How to Cite
Persico, N., Molina, F., Borenstein, M., Azumendi, G. and Nicolaides, K. H. (2010), Nasal-bone length in euploid fetuses at 16–24 weeks' gestation by three-dimensional ultrasound. Ultrasound Obstet Gynecol, 36: 285–290. doi: 10.1002/uog.7745
- Issue published online: 26 AUG 2010
- Article first published online: 12 JUL 2010
- Manuscript Accepted: 6 JUL 2010
- The Fetal Medicine Foundation
- 3D ultrasound;
- mid-sagittal plane;
- nasal bone;
To establish a normal range of nasal-bone length at 16–24 weeks' gestation by the use of three-dimensional (3D) ultrasound and to investigate the effect of deviations from the exact mid-sagittal plane on the measurement of nasal-bone length.
We acquired 3D volumes of the fetal profile from 135 normal fetuses at 16–24 weeks' gestation. The multiplanar mode was used to obtain the exact mid-sagittal plane and to produce parasagittal and oblique views of the fetal face. Nasal-bone length was measured in each plane and the sonographic landmarks of each profile view were examined.
Nasal-bone length increased with gestational age from a mean of 4.1 mm at 16 weeks to 7.1 mm at 24 weeks. There was a tendency to underestimate nasal-bone length when the measurements were taken in parasagittal planes and to overestimate the measurements when they were taken in oblique views, compared to the exact mid-sagittal plane. The mean difference in nasal-bone length from the one in the mid-sagittal plane was 0.42 and 0.63 mm for parasagittal measurements at 1 and 2 mm, respectively, from the midline, −0.08 and −0.51 mm for oblique measurements at 10° and 20° rotation along the z-axis and −0.69 mm for rotation of 20° along the z-axis and 10° along the y-axis. The vomeral bone was the only sonographic landmark defining the exact mid-sagittal plane of the face that was not visible in the parasagittal and oblique planes.
Parasagittal and oblique scanning planes may produce different degrees of under- or over-estimation of nasal-bone length compared to measurements systematically taken in the exact mid-sagittal plane. Inclusion of the vomeral bone in the definition of the exact mid-sagittal plane of the face could improve the reproducibility of measurements of nasal-bone length. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.