title: Left versus right intra-abdominal umbilical arteries: comparison of their Doppler waveforms.
abstract: OBJECTIVE
  The purpose of this study was to compare Doppler velocimetric indices between the left and right intra-abdominal umbilical arteries in normally grown and growth-restricted fetuses.
  
  
  METHODS
  In this cross-sectional study, Doppler indices of the intra-abdominal segment of the left and right umbilical arteries were measured lateral to the fetal bladder. Measurements, including the systolic to diastolic ratio and pulsatility index, were obtained from both anatomic locations. The Student t test was used to make comparisons.
  
  
  RESULTS
  Differences between left and right Doppler indices were noted in 98% of patients, and these differences were greater than 20% in at least one-third. Overall, the left umbilical artery had a higher systolic to diastolic ratio (P = .025) and pulsatility index (P = .007) than the right umbilical artery.
  
  
  CONCLUSIONS
  The laterality of the umbilical artery, whether on the left or right side of the fetus, influences important Doppler blood flow parameters.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ 08901-1977, USA. janeczsu@umdnj.edu
authors.forename: Susan
authors.initials: S
authors.lastname: Janeczek
authors.forename: Roberta
authors.initials: R
authors.lastname: Karlman
authors.forename: William
authors.initials: W
authors.lastname: MacMillan
mesh_terms: D000005:Abdomen / Q000098:blood supply / Q000000981:diagnostic imaging; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D003430:Cross-Sectional Studies; D003971:Diastole / Q000502:physiology; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005333:Fetus / Q000098:blood supply* / Q000503:physiopathology; D006801:Humans; D011247:Pregnancy; D011673:Pulsatile Flow; D013599:Systole / Q000502:physiology; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014469:Umbilical Arteries / Q000000981:diagnostic imaging* / Q000502:physiology / Q000503:physiopathology