This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gonçalves, L. F. Articles by Romero, R. Search for Related Content PubMed PubMed Citation Articles by Gonçalves, L. F. Articles by Romero, R.

Phenotypic Characteristics of Absent and Hypoplastic Nasal Bones in Fetuses With Down Syndrome

Description by 3-Dimensional Ultrasonography and Clinical Significance

Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan USA (L.F.G., M.L.S., P.D., M.M., T.C.); Perinatology Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland USA (J.E., R.R.); Division of Fetal Imaging, William Beaumont Hospital, Royal Oak, Michigan USA (W.L.); and Fetal Diagnostic Center, Pasadena, California USA (G.R.D.).

Address correspondence and reprint requests to Roberto Romero, MD, Perinatology Research Branch, National Institute of Child Health and Human Development, Department of Obstetrics and Gynecology, Wayne State University/Hutzel Hospital, 4707 St Antoine Blvd, Detroit MI 48201 USA. E-mail: warfiela{at}mail.nih.gov.

Objective. To determine the frequency and clinical significance of bilateral and unilateral hypoplastic nasal bones for the detection of Down syndrome by 3-dimensional ultrasonography. Methods. Thirty-seven volumes of the fetal skull from fetuses with Down syndrome and 37 from fetuses without abnormalities were analyzed by 1 investigator blinded to fetal karyotype. The maximum intensity projection algorithm was used to reconstruct nasal bones. Ossification patterns were identified in anteroposterior and profile views. Sensitivity, false-positive rates (FPRs), and likelihood ratios (LRs) for detection of Down syndrome were calculated. Results. After exclusions (coronal acquisition [n = 11], hand in front of the face [n = 4], poor imaging [n = 2], incomplete follow-up [n = 2], and anomalies detected after delivery [n = 2]), 53 volumes were analyzed (26 fetuses with Down syndrome and 27 without abnormalities; median gestational age, 21 6/7 weeks [interquartile range, 19 6/7–25 2/7 weeks]). Rendered profile views revealed absent nasal bones in 18.9% (10 of 53) of the fetuses, and, among these, 90% (9 of 10) had Down syndrome (sensitivity, 34.6% [9 of 26]; FPR, 3.7% [1 of 27]; LR, 9.3 [95% confidence interval (CI), 1.3–68.7]). Three ossification patterns were identified in anteroposterior views: (1) normally developed, (2) delayed ossification, and (3) absent nasal bones. Sensitivity, FPR, and LR of absent nasal bones for detecting Down syndrome were 34.6% (9 of 26), 3.7% (1 of 27), and 9.0 (95% CI, 1.3–68.7), respectively. Sensitivity, FPR, and LR of delayed ossification for detecting Down syndrome were 42.3% (11 of 26), 22% (6 of 27), and 1.83 (95% CI, 0.8–4.4). Conclusions. Absence of nasal bones is associated with the highest risk of Down syndrome. Delayed ossification is associated with a lower risk of Down syndrome than absent nasal bones. These ossification patterns may be indistinguishable on 2-dimensional ultrasonography.

Key Words: abnormalities • Down syndrome • nasal bone • 3-dimensional • ultrasonography

Abbreviations: CI, confidence interval • FPR, false-positive rate • LR, likelihood ratio • 3DUS, 3-dimensional ultrasonography • 2DUS, 2-dimensional ultrasonography

This article has been cited by other articles:

				L. F. Goncalves, W. Lee, J. Espinoza, and R. Romero Three- and 4-Dimensional Ultrasound in Obstetric Practice: Does It Help? J. Ultrasound Med., December 1, 2005; 24(12): 1599 - 1624. [Abstract] [Full Text] [PDF]