Dicke J M, Gray D L, Songster G S, Crane J P
Department of Obstetrics and Gynecology, Washington University School of Medicine, Jewish Hospital, St. Louis, Missouri.
Obstet Gynecol. 1989 Nov;74(5):726-9.
Recent studies suggest that fetal biometry may allow recognition of pregnancies at risk for Down syndrome. Second-trimester biparietal diameter (BPD)/femur length and observed-to-expected femur length ratios were examined in 48 chromosomally abnormal fetuses and compared with those of a control population composed of both low-risk patients (maternal age less than 35 years) and high-risk patients (maternal age 35 years or more). Biparietal diameter/femur length ratio correctly identified 18% of Down syndrome pregnancies with a positive predictive value of one in 169 and a false-positive rate of only 4%. When trisomies 21, 18, and 13 were considered collectively, a sensitivity of 29% and a predictive value of one in 78 were achieved, with no increase in the false-positive rate (4%). Observed-to-expected femur length ratio was less valuable in detecting chromosomally abnormal fetuses. These data suggest that the BPD/femur length ratio holds promise as a screening tool for the antenatal detection of fetal chromosomal abnormalities. Although encouraging, extrapolation of these results to other centers is not recommended without independent verification.
近期研究表明，胎儿生物测量学可能有助于识别唐氏综合征高危妊娠。对48例染色体异常胎儿的孕中期双顶径（BPD）/股骨长度以及观察到的与预期的股骨长度比值进行了检查，并与由低风险患者（母亲年龄小于35岁）和高风险患者（母亲年龄35岁及以上）组成的对照人群进行了比较。双顶径/股骨长度比值正确识别了18%的唐氏综合征妊娠，阳性预测值为1/169，假阳性率仅为4%。当将21三体、18三体和13三体合并考虑时，灵敏度为29%，预测值为1/78，且假阳性率没有增加（4%）。观察到的与预期的股骨长度比值在检测染色体异常胎儿方面价值较小。这些数据表明，双顶径/股骨长度比值有望作为产前检测胎儿染色体异常的筛查工具。尽管这些结果令人鼓舞，但在没有独立验证的情况下，不建议将这些结果推广到其他中心。
