连续顺序追踪超声法在诊断人体鱼序列征中的价值

The significance of systematic continuous sequence approach in prenatal diagnosis of sirenomelia sequence

目的探讨人体鱼序列征的产前超声影像特征及连续顺序追踪超声法在产前诊断人体鱼序列征中的应用价值。方法对2004年1月至2010年12月来我院行胎儿系统超声检查及11～13+6周颈项透明层(NT)检查的孕妇运用连续顺序追踪超声法检查胎儿四肢,对疑有人体鱼序列征的胎儿使用高频探头对四肢进行详细扫查,根据胎儿下肢发育不良程度和并腿严重程度进行超声分型(Ⅰ～Ⅶ型)。产前超声诊断结果与引产胎儿X线及尸检诊断结果进行对比分析。结果运用连续顺序追踪超声法产前诊断胎儿人体鱼序列征8例4个类型:双足并腿畸形7例(Ⅰ型2例,Ⅱ型3例,Ⅲ例2例),无足并腿畸形1例(Ⅵ型),未发现Ⅳ型、Ⅴ型(单足并腿畸形)和Ⅶ型(无足并腿畸形)胎儿;8例均合并肾脏畸形,均伴发单脐动脉起源于高位腹主动脉;其中6例无羊水,1例羊水过少,1例羊水正常。8例引产后X线及胎儿标本外观检查(尸检6例)结果与产前超声诊断结果均符合。结论中、晚孕期发现胎儿双肾缺如或双肾囊性发育不良导致无羊水时应高度警惕该畸形的发生。单脐动脉起源于高位腹主动脉为该畸形的特异性表现。11～13+6周因羊水量正常为该畸形检出的最佳时机。产前连续顺序追踪超声法是诊断人体鱼序列征准确、可靠的检查方法。

Objective To analyze the prenatal sonographic features of sirenomelia sequence and evaluate the value of systematic continuous sequence approach（SCSA）in diagnosis of this anomaly.Methods Pregnant women coming to our hospital between January 2004 and December 2010 for detailed antenatal ultrasound examination or 11-13＋6 weeks scanning were included in this study.Fetal limbsanatomy was evaluated by SCSA.Detailed examination on fetal limbs by high frequency probe was performed in fetuses suspected sirenomelia sequence.Cases with sirenomelia sequence were classified into type Ⅰto type Ⅶ according to the various degrees of hypergenetic merged lower limbs.Comparative analysis was performed on X-ray,autopsy and prenatal ultrasonograpgy.Results Eight cases with sirenomelia sequence of 4 types were detected by prenatal ultrasonographic examination,including 7 cases of sympus dipus（2 cases of typeⅠ,3 cases of type Ⅱ and 2 cases of type Ⅲ） and one case of sympus apus（type Ⅵ）.Type Ⅳ,Ⅴ（Sympus monopus） and type Ⅶ（Sympus dipus） were not found in these cases.All of the 8 cases combined with renal anomalies and a single umbilical artery arising high from the abnormal aorta.Six of these 8 cases had no amniotic fluid,1 case with severe oligohydramnios,and 1 case with normal amniotic fluid.The prenatal sonographic findings were consisted with the results of X-ray and autopsy in all the 6 cases.Conclusions Findings of no anomnios fluid resulted from renal agenesis or multicystic dysplastic kidneys is a significant clue for diagnosing sirenomelia sequence.A single umbilical artery arising high from the abnormal aorta is a specific ultrasound characteristic of sirenomelia.The optimal period for diagnosis of the abnormality is 11-13＋6 weeks.SCSA is a reliable and accurate method for prenatal evaluation of fetal limbs.