title: Prenatal and Postnatal Clinical Course of an Urachus Identified as an Allantoic Cyst in the Umbilical Cord.
abstract: OBJECTIVE
  The aim of this study was to clarify the prenatal and postnatal clinical courses of an urachus identified as an allantoic cyst in the umbilical cord.
  
  
  METHODS
  Allantoic cysts in the umbilical cord were identified in five fetuses over the past 12 years at our hospital. The prenatal and postnatal clinical courses of these patients were retrospectively reviewed.
  
  
  RESULTS
  The presence of allantoic cysts in the umbilical cord was first detected at 15 to 27 weeks of gestation. The cysts subsequently became enlarged, reaching a maximum diameter of 34 to 61 mm at 17 to 32 weeks of gestation. The cysts then suddenly disappeared due to spontaneous rupture at 26 to 35 weeks of gestation. After being born at 38 (35-39) weeks of gestation, four patients were diagnosed with a patent urachus requiring surgery in the infantile period and one was diagnosed with an urachal cyst, which is currently being observed without surgery.
  
  
  CONCLUSIONS
  The presence of an urachus identified as an allantoic cyst in the umbilical cord is frequently associated with spontaneous rupture during the prenatal period, resulting in a patent urachus after birth that requires surgical intervention.
authors.affiliation: Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Umeda
authors.affiliation: Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Usui
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kanagawa
authors.affiliation: Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Yamamichi
authors.affiliation: Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Nara
authors.affiliation: Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Takehisa
authors.initials: T
authors.lastname: Ueno
authors.affiliation: Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Owari
authors.affiliation: Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Uehara
authors.affiliation: Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Takaharu
authors.initials: T
authors.lastname: Oue
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hiroomi
authors.initials: H
authors.lastname: Okuyama
mesh_terms: D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal; D014470:Umbilical Cord / Q000503:physiopathology; D014496:Urachal Cyst / Q000000981:diagnostic imaging; D014497:Urachus / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery*