Radiology, Vol 184, 239-242, Copyright © 1992 by Radiological Society of North America

ARTICLES

Thickened nuchal fold in fetuses not at risk for aneuploidy

BR Benacerraf, LA Laboda and FD Frigoletto
Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.

Many studies have shown that a thickened nuchal fold in a second- trimester fetus is a sonographic sign suggestive of a high risk for Down syndrome. These series have included fetuses already at risk for aneuploidy because of advanced maternal age or abnormal maternal serum alpha-fetoprotein (AFP) levels. The authors describe the sonographic and karyotypic findings in 42 women younger than age 35 years whose fetuses were noted to have a thickened nuchal fold. Forty fetuses were not at risk for Down syndrome. Fourteen of the 42 fetuses (33%) had abnormal karyotypes; 11 had Down syndrome and one each had XXX, XO, and XYY. If the five cases with low maternal serum AFP levels are excluded, nine of the 37 fetuses (24%) with thickened nuchal folds had abnormal karyotypes. Amniocentesis would have been performed in one of those nine fetuses because of hydrocephalus. Thus, eight of 36 fetuses (22%) with thickened nuchal folds and no other indications for amniocentesis had abnormal karyotypes. When a thickened nuchal fold is present, the yield of abnormal karyotype is high (22%), making it possible to identify patients who would benefit from cytogenetic evaluation but who would not otherwise be candidates.

This article has been cited by other articles:

				B. Bromley, E. Lieberman, T. D. Shipp, and B. R. Benacerraf The Genetic Sonogram: A Method of Risk Assessment for Down Syndrome in the Second Trimester J. Ultrasound Med., October 1, 2002; 21(10): 1087 - 1096. [Abstract] [Full Text] [PDF]

				P. Taipale, V. Hiilesmaa, R. Salonen, and P. Ylostalo Increased Nuchal Translucency as a Marker for Fetal Chromosomal Defects N. Engl. J. Med., December 4, 1997; 337(23): 1654 - 1658. [Abstract] [Full Text] [PDF]