Kazuo FUCHIWAKI, Yukihiro NAGATA

Department of Obstetrics / Gynecology, Kagoshima University

キーワード : Umbilical cord, Ultrasonography, Nuchal cord

　When the cord coiling existed around the fetal neck, distorded grooves were formed at the surface of the nuchal skin by the pressure and strain of the umbilical cord. The ultrasonic tangential tomogram of the surface at the fetal neck indicated the cervical grooves. Thus, it was possible to estimate the number of coils on the basis of the number and width of grooves. When the number of umbilical cord coils increased, the ultrasonic tangential tomogram of the surface at the neck disclosed a bload belt-shaped echo free area, and further, the transverse tomogram of the fetal neck disclosed a doughnutlike echo free area. We examined not only existence of the nuchal cord but also the number of cord coils around the neck, in 106 pregnant women during the last trimester. A correct diagnosis of nuchal cord was made at the rate of 94.3%. It was possible to establish a diagnosis of multiple coiling of the umbilical cord around the neck (multiple nuchal cord). It should be noted that the doughnutlike echo free area appearing around cross-section of the neck in the transverse tomogram of the fetal neck is ultrasonographic findings characteristic of and specific to multiple nuchal cord.