title: Ultrasonographic detection of the second-trimester fetus with trisomy 18 and trisomy 21.
abstract: Biparietal diameter/femur length ratio and nuchal thickness were found to be sensitive indicators for the prenatal detection of trisomy 18 and trisomy 21. A biparietal diameter/femur length ratio greater than 1.5 SD above the control mean correctly identified 5 of 11 (46%) fetuses with trisomy 21 and 3 of 4 (75%) fetuses with trisomy 18. Nuchal thickening (6 mm or more) correctly identified 5 of 12 (41%) fetuses with trisomy 21 and 2 of 4 (50%) fetuses with trisomy 18. The sensitivity and specificity of the biparietal diameter/femur length ratio in detecting either aneuploidy was 53% and 93%, respectively, whereas a thickened nuchal fold had a sensitivity of 44% and a specificity of 100%. The combined use of the two ultrasonographic measurements had an overall sensitivity of 81% and a specificity of 93%. Prospective ascertainment of these two trisomies appears warranted in low-risk populations.
authors: Department of Obstetrics and Gynecology, Illinois Masonic Medical Center, Chicago.
authors: N
authors: N
authors: Ginsberg
authors: A
authors: A
authors: Cadkin
authors: E
authors: E
authors: Pergament
authors: Y
authors: Y
authors: Verlinsky
mesh_terms: D002869:Chromosome Aberrations / Q000000981:diagnostic imaging*; D025063:Chromosome Disorders; D002887:Chromosomes, Human, Pair 18; D004314:Down Syndrome / Q000000981:diagnostic imaging*; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014314:Trisomy; D014463:Ultrasonography