Hadlock F P, Harrist R B, Deter R L, Park S K
J Ultrasound Med. 1983 Mar;2(3):111-2. doi: 10.7863/jum.1983.2.3.111.
Variability (+/- 2 SD) in prediction of fetal gestational age from ultrasonographic measurements of fetal femur length was evaluated prospectively in 287 fetuses between 18 and 42 weeks' gestation. Variability increased throughout pregnancy, ranging from +/- 11.6 days between 18 and 24 weeks to +/- 22.7 days in the last six weeks of pregnancy. These findings are comparable with variability in prediction of gestational age from biparietal diameter measurement between 18 and 42 weeks, which indicates that the femur length may serve as an adequate alternative for prediction of gestational age in cases in which the biparietal diameter cannot, for technical reasons, be obtained.
前瞻性评估了287例孕18至42周胎儿，通过超声测量胎儿股骨长度预测胎儿胎龄的变异性（±2标准差）。整个孕期变异性增加，从孕18至24周时的±11.6天增加至妊娠最后六周的±22.7天。这些发现与孕18至42周时通过双顶径测量预测胎龄的变异性相当，这表明在因技术原因无法获得双顶径的情况下，股骨长度可作为预测胎龄的合适替代指标。
