胎儿足畸形的产前超声检查价值及局限性探讨

目的探讨产前超声检查在胎儿足畸形诊断中的作用及局限性，并分析胎儿足畸形产前超声漏诊原因。方法采用连续顺序超声追踪法对12371例胎儿进行常规二维及三维超声系统筛查，观察胎儿足部发育、有无异常及伴发畸形，产前超声与引产胎儿检查结果对照，总结胎儿足畸形产前超声声像图特征。结果12371例孕妇产前超声检出胎儿足畸形36例，检出率0．3％（36／12371），其中先天性足内翻畸形25例，部分趾缺如1例，足趾完全缺如2例，足缺如1例，裂足1例，小腿及足缺如1例，致死性骨发育不良5例。因足外其他系统严重畸形引产胎儿证实产前超声漏诊足畸形7例，足内翻2例，足外翻1例，多趾1例，并趾2例，趾缺如1例，漏诊率0．06（7／12371）。结论产前二维超声检查在较严重胎儿足畸形的检出、形态分类诊断方面有重要作用，选择合适的产前超声检查时间、合适的胎儿体位、连续顺序追踪超声法结合实时三维超声细致检测可提高胎儿足畸形的产前诊断准确率。

Diagnostic value and limitation of prenatal ultrasonography in detecting fetal foot malformations

Objective To evaluate the diagnostic value and limitation of prenatal ultrasonography in detecting fetal foot malformations. To analysis the causes of missed diagnosis of prenatal ultrasonography in detecting fetal foot deformity. Methods Systematic continuous sequence approach was performed with two- and three-dimensional ultrasonography to examine 12 371 cases of fetus, observing the fetal foot development, deformity and other organ deformities. Prenatal sonographic features of fetal foot deformities（36 cases） were compared with the morphology and X-ray characteristics of the delivered fetuses. Results Thirty-six cases of fetal foot deformity were diagnosed out of 12 371 by prenatal ultrasonography： 25 cases of congenital clubfoot deformity, 1 case of partial toe absence, 2 cases of complete toe absence, 1 case of foot missing, 1 case of cracked foot, 1 case of calf and foot missing, 5 cases of lethal bone dysplasia, detection rate 0.3% （36/12 371 ）. Seven cases were missed： 2 cases of congenital clubfoot deformity, 1 case of talipes valgns, 1 case of polydactyly, 1 case of syndactyly, 1 case of toe absence.The rate of misdiagnosis was 0.06%（7/12 371）. Conclusions Prenatal ultrasonography play an important role in detecting and diagnosing severe type of fetal foot deformity. The detection rate of fetal foot deformities can be greatly improved by choosing the appropriate time, right fetal position, systematic continuous sequence approach and real three-dimensional ultrasonography.