title: A simplified coculture system using homologous, attached cumulus tissue results in improved human embryo morphology and pregnancy rates during in vitro fertilization.
abstract: OBJECTIVE
  This study was undertaken to evaluate simplified methods of human embryo coculture using either attached or nonattached autologous cumulus tissue.
  
  
  METHODS
  Eight hundred one zygotes were cultured for 48 hr in a prospective, randomized trial comparing culture of embryos either with intact cumulus tissue, with cumulus tissue added to the droplet of culture medium, or without any cumulus tissue. In a follow-up study, embryo quality, pregnancy rates, and implantation rates were compared in 120 consecutive patients undergoing in vitro fertilization with a coculture system using cumulus tissue compared to a cohort of 127 patients undergoing IVF immediately preceding the institution of the coculture protocol.
  
  
  RESULTS
  Embryo morphology was significantly improved (P < 0.05) following culture with attached cumulus tissue (5.61 +/- 0.29) and culture with added cumulus tissue (4.72 +/- 0.31) compared to that of embryos grown in culture medium without cumulus tissue (3.95 +/- 0.26). The clinical pregnancy rate improved from 39.4% (50/127) to 49.2% (59/120) following institution of a system of coculture with attached cumulus tissue.
  
  
  CONCLUSIONS
  These data indicate that a simple coculture system using autologous cumulus tissue can result in improved embryo morphology, implantation rates, and clinical pregnancy rates during in vitro fertilization. This coculture system is simple, is non-labor intensive, and eliminates many of the risks which may be present in other embryo coculture systems.
authors.affiliation: Division of Urology, University of Utah School of Medicine, Salt Lake City 84132, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Carrell
authors.forename: C M
authors.initials: CM
authors.lastname: Peterson
authors.forename: K P
authors.initials: KP
authors.lastname: Jones
authors.forename: H H
authors.initials: HH
authors.lastname: Hatasaka
authors.forename: L C
authors.initials: LC
authors.lastname: Udoff
authors.forename: C E
authors.initials: CE
authors.lastname: Cornwell
authors.forename: C
authors.initials: C
authors.lastname: Thorp
authors.forename: P
authors.initials: P
authors.lastname: Kuneck
authors.forename: L
authors.initials: L
authors.lastname: Erickson
authors.forename: B
authors.initials: B
authors.lastname: Campbell
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000166:cytology* / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D006080:Ovarian Follicle / Q000166:cytology*; D011247:Pregnancy; D018873:Pregnancy Rate; D011897:Random Allocation