title: Effect of cryopreservation on the properties of human endometrial stromal cells used in embryo co-culture systems.
abstract: OBJECTIVE
  Along with comparative investigation of the decidualization potential and IL-6 secretion by fresh and frozen ESCs, we also aimed to evaluate the effectiveness of co-culture systems based on fresh or frozen ESCs in terms of clinical pregnancy rates.
  
  
  METHODS
  Outcome analysis of a total of 215 IVF cycles with co-culture with fresh or frozen ESCs was performed. Endometrial tissue was obtained from 17 healthy donors. Concentrations of secreted prolactin, IGFBP-1, and IL-6 in conditioned media from cultured fresh and frozen ESCs (decidualized or not) were measured using ELISA or ECLIA.
  
  
  RESULTS
  Embryo co-culture with frozen ESCs resulted in a much lower pregnancy rate compared to the alternative system using fresh ESCs. Furthermore, cultivated frozen ESCs showed considerably decreased release of prolactin, IGFBP-1, and IL-6 compared to fresh ESCs, indicating that cryopreservation negatively affects their decidualization potential and cytokine production.
  
  
  CONCLUSIONS
  Altogether, this data illustrates the need for optimization and improvement of the existing autologous endometrial co-culture systems.
authors.affiliation: IVF Department, Ob/Gyn Hospital Dr. Shterev, 25-31 Hristo Blagoev Str., 1330, Sofia, Bulgaria. lakatush@yahoo.com.
authors.forename: Ivan
authors.initials: I
authors.lastname: Bochev
authors.affiliation: Tissue bank BULGEN, 25-31 Hristo Blagoev Str., 1330, Sofia, Bulgaria.
authors.forename: Kalina
authors.initials: K
authors.lastname: Belemezova
authors.affiliation: IVF Department, Ob/Gyn Hospital Dr. Shterev, 25-31 Hristo Blagoev Str., 1330, Sofia, Bulgaria.
authors.forename: Atanas
authors.initials: A
authors.lastname: Shterev
authors.affiliation: Tissue bank BULGEN, 25-31 Hristo Blagoev Str., 1330, Sofia, Bulgaria.|Institute of Reproductive Health, 25-31 Hristo Blagoev Str., 1330, Sofia, Bulgaria.
authors.forename: Stanimir
authors.initials: S
authors.lastname: Kyurkchiev
mesh_terms: D018920:Coculture Techniques / Q000379:methods*; D015925:Cryopreservation; D004717:Endometrium / Q000166:cytology / Q000378:metabolism; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D011247:Pregnancy; D018873:Pregnancy Rate; D011388:Prolactin / Q000378:metabolism; D027724:Reproductive Techniques, Assisted; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism
chemical_list: D018970:Insulin-Like Growth Factor Binding Protein 1; D015850:Interleukin-6; D011388:Prolactin
keywords: Cryopreservation; Cytokine production; Decidualization; Embryo co-culture; Endometrial stromal cells; Pregnancy rate