HealthGate Document

Title

Can sonographers reliably identify anatomic features associated with Down syndrome in fetuses?

Author

Benacerraf BR; Cnann A; Gelman R; Laboda LA; Frigoletto FD Jr

Address

Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, MA.

Source

Radiology, 1989 Nov, 173:2, 377-80

Abstract

To standardize femur measurement for the identification of fetuses at risk for Down syndrome, sonographers of varying professional experience and background measured the femurs of 20 Down syndrome fetuses and 709 normal control fetuses. A regression analysis performed to compare biparietal diameter to femur length on the 709 control fetuses yielded the following formula: expected femur length = -9.3105 + 0.9028.biparietal diameter. A ratio of measured-to-expected femur length of 0.91 or lower indicated Down syndrome with a sensitivity of 40%, a specificity of 95%, and a positive predictive value of 3.1%. Eight of the 20 fetuses with Down syndrome (40%) also had a thickened nuchal fold (6 mm or larger). If the nuchal fold findings had been considered with the femur length findings, two more of the fetuses with Down syndrome would have been identified, yielding a sensitivity of 45% and a positive predictive value of 4.3%. Because these measurements were made by eight sonographers rather than a single experienced sonologist, these results could be achieved in most ultrasound laboratories where measurements are done primarily by sonographers.

Language of Publication

English

Unique Identifier

90018384

MeSH Heading (Major)

Down Syndrome|*DI/PA; Fetal Diseases|*DI/PA; Prenatal Diagnosis|*; Ultrasonography|*

MeSH Heading

Female; Femur|PA; Fetus|PA; Human; Neck|PA; Parietal Bone|PA; Predictive Value of Tests; Pregnancy; Sensitivity and Specificity

Publication Type

JOURNAL ARTICLE

ISSN

0033-8419

Country of Publication

UNITED STATES