title: Angiogenesis in implantation.
abstract: OBJECTIVE
  Implantation failure and early pregnancy loss are common following natural conceptions and they are particularly important clinical hurdles to overcome following assisted reproduction attempts. The importance of adequate vascular development and maintenance during implantation has recently become a major focus of investigation.
  
  
  METHODS
  Review of current published literature was undertaken to summerize the cells and cell products that regulate tissue vascularity during implantation.
  
  
  RESULTS
  Vascular development at the maternal fetal interface can be regulated by a number of different cell types; two principal candidates are trophoblast and natural killer cells. A wide range of soluble factors, some with well established angiogenic functions as well as other more novel factors, can contribute to vascular development and maintenance at the maternal-fetal interface.
  
  
  CONCLUSIONS
  Robust vascular development occurs during implantation and early placentation of normal pregnancies. Studies to define the extent and mechanisms by which defects in vascularity contribute to human implantation failure and early miscarriage need to be undertaken.
authors.affiliation: Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, P.O. Box 19626, Springfield, IL 62794-9626, USA. dtorry@siumed.edu
authors.forename: Donald S
authors.initials: DS
authors.lastname: Torry
authors.forename: Jonathan
authors.initials: J
authors.lastname: Leavenworth
authors.forename: Miao
authors.initials: M
authors.lastname: Chang
authors.forename: Vatsala
authors.initials: V
authors.lastname: Maheshwari
authors.forename: Kathleen
authors.initials: K
authors.lastname: Groesch
authors.forename: Evan R
authors.initials: ER
authors.lastname: Ball
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Torry
mesh_terms: D010064:Embryo Implantation / Q000502:physiology*; D004717:Endometrium / Q000098:blood supply* / Q000378:metabolism; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000502:physiology; D011247:Pregnancy; D042442:Vascular Endothelial Growth Factors / Q000502:physiology
chemical_list: D042442:Vascular Endothelial Growth Factors