title: Prenatal sonographic diagnosis of single umbilical artery: Emphasis on the absent side and its relation to associated anomalies.
abstract: OBJECTIVE
  To determine the absent side of a single umbilical artery (SUA) and to evaluate whether associated anomalies are related to the side of the missing artery in a Taiwanese population.
  
  
  METHODS
  We retrospectively studied SUA fetuses from our computer database of fetal ultrasound in a tertiary medical center in Southern Taiwan. All cases were diagnosed as SUA prenatally using conventional scanners of two- and three-dimensional (2D and 3D, respectively) ultrasound, as well as color, power, and high-definition Doppler. The absent side of UA and associated anomalies were analyzed.
  
  
  RESULTS
  From September 2006 to November 2011, 31 fetuses with SUA were diagnosed prenatally by ultrasound and all were enrolled for this series. The incidence was estimated to be 1:556 (0.18% = 31/17,086). The mean maternal age was 29.2 years (range, 15-36 years) and the mean fetal age was 30.0 weeks of gestation (range 18-36 weeks). Notably, the left-absent UA was detected in 16/31 (52%) fetuses, compared with the right-absent UA in 15/31 (48%) cases. In addition, congenital anomalies were noted prenatally in 2/16 (13%) fetuses with left-absent UA and in 3/15 (20%) fetuses with right-absent UA.
  
  
  CONCLUSIONS
  In SUA fetuses, the absence of UA appears to occur equally at each side. Moreover, this study showed no significant difference between either side of missing UA and associated anomalies after statistical examination.
authors.affiliation: Department of Obstetrics and Gynecology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Yu-Peng
authors.initials: YP
authors.lastname: Wu
authors.affiliation: Department of Obstetrics and Gynecology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Hsing-Fen
authors.initials: HF
authors.lastname: Tsai
authors.affiliation: Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Yueh-Chin
authors.initials: YC
authors.lastname: Cheng
authors.affiliation: Department of Obstetrics and Gynecology, National Cheng Kung University Hospital, Tainan, Taiwan; Research Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Lin
authors.initials: L
authors.lastname: Kang
authors.affiliation: Department of Obstetrics and Gynecology, National Cheng Kung University Hospital, Tainan, Taiwan; Research Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Pei-Ying
authors.initials: PY
authors.lastname: Tsai
authors.affiliation: Department of Obstetrics and Gynecology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Chen-Hsiang
authors.initials: CH
authors.lastname: Yu
authors.affiliation: Department of Obstetrics and Gynecology, National Cheng Kung University Hospital, Tainan, Taiwan. Electronic address: ahsin@mail.ncku.edu.tw.
authors.forename: Chiung-Hsin
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Department of Obstetrics and Gynecology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Fong-Ming
authors.initials: FM
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D000013:Congenital Abnormalities / Q000000981:diagnostic imaging*; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D012189:Retrospective Studies; D013624:Taiwan; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: associated anomalies; prenatal; single umbilical artery; ultrasound