Dudiak C M, Salomon C G, Posniak H V, Olson M C, Flisak M E
Department of Radiology, Loyola University Medical Center, Maywood, IL 60153, USA.
Radiographics. 1995 Sep;15(5):1035-50. doi: 10.1148/radiographics.15.5.7501849.
Knowledge of the development, normal sonographic appearance, and potential abnormalities of the umbilical cord is important in fetal assessment. The umbilical cord can be visualized throughout most of gestation and is detectable sonographically soon after visualization of the fetal pole. The normal umbilical cord is 50-60 cm long and may coil as many as 40 times, usually to the left. Abnormalities in umbilical cord size, degree of coiling, attachment, and position can have important implications for the outcome of the pregnancy. Structural abnormalities of the umbilical cord such as single umbilical artery, knots, cysts, and tumors may be associated with fetal distress or malformations. Color Doppler ultrasound (US) is useful in the identification and evaluation of structural abnormalities of the cord. By allowing measurement of blood flow velocity in the umbilical artery, duplex Doppler US may provide additional information in the evaluation of intrauterine growth retardation and twin-twin transfusion syndrome.
了解脐带的发育、正常超声表现及潜在异常对胎儿评估很重要。在孕期的大部分时间里都能看到脐带，在看到胎芽后不久就能通过超声检测到。正常脐带长50 - 60厘米，可能盘绕多达40次，通常向左盘绕。脐带大小、盘绕程度、附着及位置异常可能对妊娠结局有重要影响。脐带结构异常，如单脐动脉、打结、囊肿和肿瘤，可能与胎儿窘迫或畸形有关。彩色多普勒超声（US）有助于识别和评估脐带结构异常。通过测量脐动脉血流速度，双功多普勒超声可能为评估宫内生长迟缓及双胎输血综合征提供更多信息。
