超声不同数学公式评估中国胎儿体重的准确性分析

目的：针对中国人种，在不同孕周，比较12种超声估计胎儿体重的公式来预测新生儿体重的准确性。并同时比较经验丰富与新手之间评估准确性的差异。方法：回顾性分析对488例单胎中国人得胎儿体重用12种公式分别评估胎儿体重。胎儿生物学测量的径线在分娩前7天测量。结果：488例孕妇中，31例（6．4％）为小于胎龄儿（SGA），36例（7．3％）为大于胎龄儿。对于所有的病例，Aoki和HadlockI有最好的组内相关效率。对于SGA而言，Combs的预测效率最高。对于体重在2501g至3999g之间的胎儿，Aoki的预测效率最高。对于LGA，Merz公式有最强的预测准确率。在经验丰富与新手预测胎儿体重的准确性方面，经过系统训练的熟练操作人员的准确性明显高于新手的评估准确率。结论：在决定分娩时机和分娩方式，尤其是在需要催产或期待妊娠时，临床上必须要考虑到胎儿体重的情况。在不同种族，不同体重范围时应该运用不同的超声胎儿体重的公式。超声工作者应该在上岗前系统的培训超声测量胎儿体重的标准平面及操作技巧以提高评估的准确性。

Accuracy of Fetal Weight Estimation by Ultrasound with Different Formulas in Localized Chinese Population

Objectives： Accurate fetal weight estimation helps obstetricians with decision-making on timing and mode of deliv- ery. Our aim is to compare the accuracy of twelve sonographic formulas for predicting fetal birth weight at different gestational weeks in a Chinese population and compare the accuracy of the estimation by experienced and inexperienced sonographer. Methods：This retrospective study was conducted at the Obstetrics Department of Guangzhou Women and Children＇ s Health Care Center in 2009. Inclusion criteria were singleton pregnancy, ultrasound examination with complete biometric parameters within 7 days of delivery, and a live born infant without congenital malformation or hydrops. There were 12 different formulas evaluated in 488 Chinese pregnancies. Full fetal biometry parameters were measured within 7 days of delivery by the sonogra- phers in our department. Results：A total of 488 patients were included in the study, 31 （6.4%） were SGA and 36 （7.3%） were LGA. Across the entire weight range, Aoki and Hadlock I had the best intraclass correlation coefficients. For SGA fetuses, Combs has the best accuracy level. For birth weight between 2501g and 3999g Aoki shows the best accuracy level. For LGA fetuses, Merz has the best accuracy level for fetal weight estimation. Less estimation error was seen when measurements were obtained by a more experienced sonographer. Conclusions：Estimated fetal weight is taken into consideration when making clinical decisions involving induction or delay of labor and when deciding on the method of delivery. Formula should be select- ed in a certain population and within a certain fetal weight range. Sonographers should be trained adequately to get standard ul- trasound planes for fetal biometry measurements.