“λ”型脐带入口的产前超声诊断

The diagnosis of "λ" shape of umbilical cord entrance by prenatal ultrasonographic

目的探讨产前超声在诊断"λ"型脐带入口的价值。方法回顾性分析12例全部经临床证实的"λ"型脐带入口的声像图特点并随访胎儿预后。结果产前超声诊断的12例"λ"型脐带入口出生后皆经临床证实,其声像图特征是:脐带在未插入胎盘前脐血管分支过早,脐带和脐血管分支呈"λ"型分别插入胎盘;按照脐血管分支类型分为三型:脐动脉分支型、脐静脉分支型及混合型。经过随访,10例发现血性羊水,2例胎儿死亡,9例合并胎盘形态异常。其中脐静脉分支型容易断裂,引起血性羊水,但其预后良好,而脐动脉分支型断裂,可导致胎儿出血,甚至死亡。结论彩色多普勒超声能直接显示脐带胎盘端分支情况,是诊断"λ"型脐带入口的首选方法,对解释血性羊水的成因及不明原因的胎儿死亡有重要的临床价值。

Objective To explore the clinical value of color Doppler in the diagnosis of ＂λ＂ shape umbilical cord entrance.Methods A retrospective analysis was made on the sonographic features of 12 cases of ＂λ＂ shape umbilical cord entrance and then follow-up was carried out for the fetal outcome.Results 12 cases of ＂λ＂ shape umbilical cord entrance diagnosed by ultrasound were proved after delivery.The typical ultrasonographic features were given as follows： the umbilical vessels branch too early before the umbilical cord inserting into the placenta;the umbilical cord and the branches of umbilical vessels insert into the placenta respectively in a ＂λ＂ shape.According to the branch,it was divided into three types： umbilical arterial branch type,umbilical vein branch type and the mixed type.After follow-up,10 cases were found hemorrhagic amniotic fluid,2 cases of fetal deaths,and 9 cases with abnormal placenta.Umbilical vein branch type was easy to be broken,which causes hemorrhagic amniotic fluid,but the prognosis was good.Umbilical arterial branch type was fractured,which caused fetal bleeding,and even fetal death.Conclusion Color Doppler ultrasound which can directly display the branches of umbilical cord,is the preferred method for the diagnosis of ＂λ＂ shape umbilical cord entrance,and it is of important clinical value to explain the causes of hemorrhagic amniotic fluid and unexplained fetal deaths.