title: Cumulus mass maintains embryo quality.
abstract: OBJECTIVE
  To determine if co-culture of early stage embryos with their own cumulus mass improves embryo quality.
  
  
  METHODS
  Before insemination, cumulus masses along with cumulus matrices were separated from the oocytes surrounded by a few remaining cumulus cells. Fourteen hours after insemination, fertilized oocytes were each placed onto the cumulus cells, and matrix and co-culture commenced. The embryos were observed every 24 hours. Fifty-three oocytes were treated in co-culture (C) and 59 oocytes were treated in routine culture (U).
  
  
  RESULTS
  Thirty-four (C) and 43 (U) oocytes were fertilized and placed on growth media for further culture. Twenty-four hours after culture, 10 embryos (29%) in C and 12 (28%) in U were good quality, and 4 embryos (12%) in C and 7 (16%) in U were of poor quality. Seventy-two hours after culture, 10 (29%) in C and 8 (18%) in U were of good quality, and 3 (9%) in C and 13 (30%) were of poor quality. The percentage of good quality embryos in the co-culture group was significantly higher than in the control group after 72 hours. Conversely, the percentage of poor quality embryos in the co-culture group was significantly lower than that in the control group after 72 hours.
  
  
  CONCLUSIONS
  Co-culture maintains embryo quality over prolonged culture times. This facilitates the development of good quality embryos for ET.
authors.affiliation: Department Obstetrics and Gynecology, Yamagata University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: T
authors.initials: T
authors.lastname: Hirayama
authors.forename: K
authors.initials: K
authors.lastname: Koike
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: M
authors.initials: M
authors.lastname: Nohara
authors.forename: M
authors.initials: M
authors.lastname: Hiroi
mesh_terms: D002478:Cells, Cultured; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000502:physiology*; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D006080:Ovarian Follicle / Q000166:cytology*; D011247:Pregnancy