title: Novel concepts of human chorionic gonadotropin: reproductive system interactions and potential in the management of infertility.
abstract: OBJECTIVE
  To extensively review the scientific literature on the potential sites of hCG action and the role of this hormone on reproductive processes not necessarily related to the classic hCG functions of supporting early pregnancy.
  
  
  METHODS
  Review of the international scientific literature and the authors' personal research experience in this area.
  
  
  RESULTS
  The LH/hCG receptor has an almost ubiquitous distribution in reproductive organs, thus suggesting that the actions of hCG might be more extensive than previously thought. Independently of FSH, low-dose hCG can support development and maturation of larger ovarian follicles that have acquired granulosa cells LH/hCG receptors, potentially providing effective and safer ovulation induction regimens. Human chorionic gonadotropin seems to be capable of improving uterine receptivity by enhancing endometrial quality and stromal fibroblast function. Furthermore, through its actions on insulin-like growth factor binding protein-1 and vascular endothelial growth factor, hCG might stimulate endometrial angiogenesis and growth and extend the implantation window, thus making pregnancy more likely.
  
  
  CONCLUSIONS
  Mounting evidence indicates that hCG could be mediating relevant actions enhancing fertility and the efficacy of therapeutic procedures used in the management of infertility. Greater understanding of the physiologic roles that hCG plays in human reproduction might suggest novel clinical applications for this traditional hormone of pregnancy.
authors.affiliation: Reproductive Endocrinology Center, University of Bologna, Bologna, Italy. marco.filicori@unibo.it
authors.forename: Marco
authors.initials: M
authors.lastname: Filicori
authors.forename: Asgerally T
authors.initials: AT
authors.lastname: Fazleabas
authors.forename: Ilpo
authors.initials: I
authors.lastname: Huhtaniemi
authors.forename: Peter
authors.initials: P
authors.lastname: Licht
authors.forename: Ch V
authors.initials: ChV
authors.lastname: Rao
authors.forename: Jan
authors.initials: J
authors.lastname: Tesarik
authors.forename: Marek
authors.initials: M
authors.lastname: Zygmunt
mesh_terms: D000818:Animals; D006063:Chorionic Gonadotropin / Q000502:physiology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007246:Infertility / Q000188:drug therapy* / Q000378:metabolism; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted / Q000639:trends
chemical_list: D006063:Chorionic Gonadotropin