title: Detection of umbilical venous constriction by Doppler flow measurement at midgestation.
abstract: OBJECTIVE
  To investigate whether umbilical venous velocity and venous velocity pulsation are associated with umbilical vein diameter, umbilical ring diameter and umbilical cord coiling index at midgestation.
  
  
  METHODS
  Two hundred and eighty pregnant women were enrolled in the study at between 18 and 24 weeks of gestation. The diameter of the umbilical cord and internal diameter of the umbilical vein in a free loop and at the ring, and the umbilical coiling index, were measured using ultrasonography. Umbilical venous velocities were measured by Doppler ultrasonography at the umbilical ring and a free loop of the cord.
  
  
  RESULTS
  All variables were successfully measured in 92% of the patients. There were negative correlations between the diameters of the umbilical ring and of the umbilical vein at the ring and the venous velocity at the umbilical ring. The venous velocity at the umbilical ring was significantly higher and the umbilical ring diameter was significantly lower in fetuses with umbilical venous pulsation at the free loop. Significant correlations were observed between the venous velocity and amplitude of pulsation. Venous pulsations at the free loop were frequently observed in fetuses with a hypercoiled cord.
  
  
  CONCLUSIONS
  High venous velocity and increased venous pulsation at the umbilical ring may be associated with umbilical cord constriction.
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan. hasejun@oak.dti.ne.jp
authors.forename: J
authors.initials: J
authors.lastname: Hasegawa
authors.forename: T
authors.initials: T
authors.lastname: Mimura
authors.forename: T
authors.initials: T
authors.lastname: Morimoto
authors.forename: R
authors.initials: R
authors.lastname: Matsuoka
authors.forename: K
authors.initials: K
authors.lastname: Ichizuka
authors.forename: A
authors.initials: A
authors.lastname: Sekizawa
authors.forename: T
authors.initials: T
authors.lastname: Okai
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D016001:Confidence Intervals; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal / Q000379:methods; D014471:Umbilical Veins / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000503:physiopathology*