title: Three-dimensional ultrasonographic assessment of the umbilical cord during the 2nd and 3rd trimesters of pregnancy.
abstract: OBJECTIVE
  To evaluate the umbilical cord and its abnormalities by use of three-dimensional ultrasonography with a specially developed abdominal three-dimensional transducer.
  
  
  METHODS
  Ninety-five pregnancies (92 normal, 2 with hydrops fetalis, and 1 with omphalocele) from 14 to 40 weeks of gestation were studied with a specially developed abdominal three-dimensional transducer (3.5 MHz). This system can provide conventional two-dimensional ultrasonography images and can also generate within seconds high-quality three-dimensional images in the surface and transparent mode with no need for an external workstation. A proportion of the umbilical cords (coiled or noncoiled free loop, abdominal insertion, and placental insertion) visualized at each gestational age interval is presented.
  
  
  RESULTS
  The proportion of the umbilical cords visualized during pregnancy except for between 24 and 27 weeks of gestation was about 70% (range 64-83%). Optimal visualization of the umbilical cord was achieved between 24 and 27 weeks of gestation. During this period it was possible to adequately depict the umbilical cord in 93% of the cases. The proportions of the noncoiled umbilical cord depicted during pregnancy ranged from 8 to 45%. The detection rate of abdominal insertion of the umbilical cord visualized at 14-19 weeks was 44%; the detection rate decreased thereafter. Placental insertion of the umbilical cord could not be identified after 28 weeks of gestation. In 2 cases with hydrops fetalis, edematous umbilical cord was evident. In 1 fetus, omphalocele was clearly depicted.
  
  
  CONCLUSIONS
  The new three-dimensional ultrasound technology generates within seconds high-quality three-dimensional images of the umbilical cord, although limitation of viewing direction exists. These results suggest that the new three-dimensional ultrasonography has the potential to be a supplement to two-dimensional ultrasonography and might be useful in identifying abnormal umbilical cords in utero.
authors.affiliation: Department of Obstetrics and Gynecology, Shimane Medical University, Izumo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hata
authors.forename: S
authors.initials: S
authors.lastname: Aoki
authors.forename: K
authors.initials: K
authors.lastname: Hata
authors.forename: K
authors.initials: K
authors.lastname: Miyazaki
mesh_terms: D004487:Edema / Q000000981:diagnostic imaging; D005260:Female; D005865:Gestational Age; D006554:Hernia, Umbilical / Q000000981:diagnostic imaging; D006801:Humans; D015160:Hydrops Fetalis / Q000000981:diagnostic imaging; D011247:Pregnancy; D016216:Ultrasonography, Prenatal; D014470:Umbilical Cord / Q000000981:diagnostic imaging*