Nasal Bone Evaluation in Fetuses With Down Syndrome During the Second and Third Trimesters of Pregnancy
Wesley Lee, MD, Greggory R. DeVore, MD, Christine H. Comstock, MD, Karim D. Kalache, MD, Beverley McNie, Tinnakorn Chaiworapongsa, MD, Giancarlo Conoscenti, MD, Marjorie C. Treadwell, MD, Anthony Johnson, MD, Raywin Huang, PhD and Roberto Romero, MD
Division of Fetal Imaging, Department of Obstetrics and Gynecology (W.L., C.H.C., B.M.), and Division of Biostatistics (R.H.), William Beaumont Hospital, Royal Oak, Michigan; Perinatology Research Branch, National Institute of Child Health and Human Development, Bethesda, Maryland (W.L., G.R.D., K.D.K., T.C., G.C., R.R.); and Hutzel Hospital, Wayne State University, Detroit, Michigan (W.L., C.H.C., M.C.T., A.J., R.R.) USA.
Address correspondence and reprint requests to Wesley Lee, MD, Division of Fetal Imaging, Department of Obstetrics and Gynecology, William Beaumont Hospital, 3601 W Thirteen Mile Rd, Royal Oak, MI 48073-6769 USA.
Objective. This study examined the use of three-dimensional ultrasonography for evaluating the fetal nasal bone, as a sonographic marker of Down syndrome, during the second and early third trimesters of pregnancy. Methods. Forty fetuses, including 20 with trisomy 21, were scanned once by three-dimensional ultrasonography. A midline sagittal view of the facial profile was used to analyze the volume data. Independent examiners reviewed blinded and randomly allocated volume data sets for the nasal bone. Interobserver reliability was evaluated for the sonographic presence or absence of the nasal bone. Logistic regression determined the contribution of this parameter to the presence of Down syndrome. Results. Both examiners showed substantial agreement in scoring whether the nasal bone was visualized by three-dimensional ultrasonography (P < .001). They identified 40% to 45% of fetuses with abnormalities using the absence of the nasal bone as a sonographic marker. However, a substantial number of fetuses with abnormalities were also found to have a nasal bone present. The nasal bone was visualized in 80% to 90% of fetuses without abnormalities. Conclusions. Three-dimensional ultrasonography can be used to evaluate the fetal nasal bone with substantial interobserver agreement during the second and early third trimesters of pregnancy. A nonvisualized nasal bone identified 40% to 45% of fetuses with Down syndrome in this study. |
