title: Shunting the intervillous space: new concepts in human uteroplacental vascularization.
abstract: OBJECTIVE
  It is supposed that the intervillous space is not perfused by maternal blood during the first trimester, suggesting vascular shunts in the myometrium. We therefore attempted to provide arguments for a functional vascular anastomotic network located in the placental bed during human pregnancy.
  
  
  METHODS
  Three-dimensional (3D) sonography, laboratory analyses, and anatomic studies (hysterectomy specimens, uteroplacental vascular cast) were performed.
  
  
  RESULTS
  Color Doppler showed a vascular network with anastomotic aspect located in the placental bed. A vascular cast of a uterus, obtained after postpartum hemorrhage, demonstrated a vascular anastomotic network in the myometrium. Higher PO2 levels in the uterine vein compared with the intervillous space confirmed the functional nature of this shunt. Low resistances in the uterine arteries during the first week after delivery suggested that this vascular network remains functional after placental expulsion.
  
  
  CONCLUSIONS
  Our studies have yielded functional and anatomic evidence of an arteriovenous shunt located in the subplacental myometrium.
authors.affiliation: Department of Obstetrics and Gynecology, CHR de la Citadelle, Liége, Belgium. jean.pierre.schaaps@chrcitadelle.be
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Schaaps
authors.forename: Vassilis
authors.initials: V
authors.lastname: Tsatsaris
authors.forename: Frederic
authors.initials: F
authors.lastname: Goffin
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Brichant
authors.forename: Katty
authors.initials: K
authors.lastname: Delbecque
authors.forename: Malek
authors.initials: M
authors.lastname: Tebache
authors.forename: Laurent
authors.initials: L
authors.lastname: Collignon
authors.forename: Maria Christina
authors.initials: MC
authors.lastname: Retz
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Foidart
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008954:Models, Biological; D010920:Placenta / Q000098:blood supply* / Q000000981:diagnostic imaging; D021041:Placental Circulation; D049590:Postpartum Period; D011247:Pregnancy; D011264:Pregnancy Trimesters / Q000502:physiology*; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal