Ultrasound diagnosis and management of umbilical cord abnormalities.

The incidence of placenta and umbilical cord abnormalities is high in abnormal course of the delivery. Although the detection rate of umbilical cord abnormalities is steadily increasing with the improvement of ultrasound technology, and the fact that ultrasound scanning can distinguish umbilical cord conditions, this information has not exerted much impact on the management of labor to date. We believe prenatal detection of umbilical cord abnormalities must reduce the number of emergent cesarean sections and intrauterine fetal death. In this review, we describe the ultrasound diagnosis and management of major umbilical cord abnormalities, including abnormalities of cord insertion site (velamentous and marginal cord insertion), hypercoiled cord and nuchal cord, considering the current knowledge on physiologic and pathologic aspects of each umbilical cord abnormality.