Johnson M P, Michaelson J E, Barr M, Treadwell M C, Hume R F, Dombrowski M P, Evans M I
Department of Obstetrics and Gynecology, Hutzel Hospital-Wayne State University, Detroit, Michigan, USA.
Am J Obstet Gynecol. 1995 Apr;172(4 Pt 1):1229-35. doi: 10.1016/0002-9378(95)91484-6.
Our purpose was to evaluate the value of the combination of femur and humerus length measurements in ultrasonographic screening for trisomy 21.
Direct necropsy measurements were analyzed on 703 midgestational fetuses (641 normal, 62 with trisomy 21). The (leg+arm length)/foot length ratio was found to be significantly shortened for fetuses with trisomy 21. On the basis of necropsy data 576 midgestational pregnancies were evaluated ultrasonographically for (femur+humerus length)/foot length ratio to identify fetuses at increased risk for trisomy 21.
An ultrasonographic (femur+humerus length)/foot length ratio < or = 1.75 gave a 15.3 odds ratio risk for trisomy 21 in our high-risk population and correctly identified 53% of fetuses with trisomy 21, with a false-positive rate of 7%. In addition, the use of this ratio eliminates the need for gestational age-corrected nomograms and complicated calculations in ultrasonographic screening.
The (femur+humerus length)/foot length ratio may be an additional effective ultrasonographic marker for identification of fetuses at increased risk for trisomy 21.
我们的目的是评估股骨和肱骨长度测量相结合在超声筛查21三体综合征中的价值。
对703例孕中期胎儿（641例正常，62例21三体综合征）进行直接尸检测量。发现21三体综合征胎儿的（腿+臂长）/足长比值显著缩短。根据尸检数据，对576例孕中期妊娠进行超声检查，评估（股骨+肱骨长度）/足长比值，以识别21三体综合征风险增加的胎儿。
在我们的高危人群中，超声（股骨+肱骨长度）/足长比值≤1.75时，21三体综合征的优势比风险为15.3，正确识别了53%的21三体综合征胎儿，假阳性率为7%。此外，使用该比值无需在超声筛查中使用孕周校正的列线图和复杂计算。
（股骨+肱骨长度）/足长比值可能是识别21三体综合征风险增加胎儿的另一种有效的超声标志物。
