Second trimester ultrasonography may identify 77 to 97% of fetuses with trisomy 18.
Between 1990 and 1999, 30 second trimester fetuses with trisomy 18 and 2000 control fetuses underwent real-time and color Doppler ultrasonographic examination followed by genetic amniocentesis. Abnormal fetal anatomy was present in 97% of fetuses with trisomy 18, with a false-positive rate of 15.7%. Logistic regression identified six markers (choroid plexus cysts, central nervous system malformations, an abnormal nuchal skin fold, ventricular septal defect, outflow tract abnormalities of the heart, and right-to-left chamber disproportion of the heart) and one interaction between markers (right-to-left chamber disproportion and outflow tract abnormalities) to significantly contribute to the identification of 93% of fetuses with trisomy 18, with a false-positive rate of 8.9%. Noncardiovascular markers (choroid plexus cysts, central nervous system malformations, and abnormal nuchal skin fold) identified 77% of fetuses with trisomy 18, with a false-positive rate of 3.9%. Combining right-to-left chamber disproportion of the heart with choroid plexus cysts, central nervous system malformations, and nuchal skin folds identified 83% of fetuses with trisomy 18, with a false-positive rate of 4.4%.
DeVore
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GR
Fetal Diagnostic Center of Pasadena, California 91105, USA.
D000015:Abnormalities, Multiple / Q000000981:diagnostic imaging / Q000235:genetics*; D001921:Brain / Q000002:abnormalities*; D002831:Choroid Plexus / Q000002:abnormalities / Q000000981:diagnostic imaging; D002887:Chromosomes, Human, Pair 18; D003560:Cysts / Q000000981:diagnostic imaging / Q000235:genetics; D005260:Female; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000235:genetics*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D018570:Risk Assessment; D014314:Trisomy; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal