title: A combination of hydroxypropyl cellulose and trehalose as supplementation for vitrification of human oocytes: a retrospective cohort study.
abstract: OBJECTIVE
  This study aimed to determine whether the new formulation of vitrification solutions containing a combination of hydroxypropyl cellulose (HPC) and trehalose does not affect outcomes in comparison with using conventional solutions made of serum substitute supplement (SSS) and sucrose.
  
  
  METHODS
  Ovum donation cycles were retrospectively compared regarding the solution used for vitrification and warming of human oocytes. The analysis included 218 cycles (N = 2532 oocytes) in the study group (HPC + trehalose) and 214 cycles (N = 2353 oocytes) in the control group (SSS + sucrose).
  
  
  RESULTS
  No statistical differences were found in ovarian stimulation parameters and baseline characteristics of donors and recipients. The survival rate was 91.3% (95% confidence interval (CI) = 89.8-92.9) in the HPC + trehalose group vs. 92.1% (95% CI = 90.4-93.7) in the SSS + sucrose group (NS). The implantation rate (42.8%, 95% CI = 37.7-47.9 vs. 41.2%, 95% CI = 36.0-46.4), clinical pregnancy rate (CPR) per transfer (60.7%, 95% CI = 53.9-67.5 vs. 56.4%, 95% CI = 49.3-63.5), and ongoing pregnancy rate (OPR) per transfer (48.5%, 95% CI = 41.5-55.5 vs. 46.3%, 95% CI = 39.2-53.4) were similar for patients who received either HPC + trehalose-vitrified oocytes or SSS + sucrose-vitrified oocytes. Statistical differences were found when analyzing blastocyst rate both per injected oocyte (30.2%, 95% CI = 28.3-32.1 vs. 24.1%, 95% CI = 22.3-25.9) and per fertilized oocyte (40.8%, 95%CI = 38.5-43.1 vs. 33.2%, 95% CI = 30.8-35.5) (P < 0.0001). Delivery rate was comparable between groups (37.2%, 95% CI = 30.8-46.6 vs. 36.9%, 95% CI = 30.4-43.4; NS).
  
  
  CONCLUSIONS
  Our data demonstrate that HPC and trehalose are suitable and safe substitutes for serum and sucrose. Therefore, the new commercial media can be used efficiently in the vitrification of human oocytes avoiding viral and endotoxin contamination risk.
authors.affiliation: Instituto Valenciano de Infertilidad (IVI), University of Valencia, Pl. Policía Local 3, Valencia, Spain.
authors.forename: Aila
authors.initials: A
authors.lastname: Coello
authors.affiliation: Instituto Valenciano de Infertilidad (IVI), University of Valencia, Pl. Policía Local 3, Valencia, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Campos
authors.affiliation: Instituto Valenciano de Infertilidad (IVI), University of Valencia, Pl. Policía Local 3, Valencia, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Remohí
authors.affiliation: Instituto Valenciano de Infertilidad (IVI), University of Valencia, Pl. Policía Local 3, Valencia, Spain.
authors.forename: Marcos
authors.initials: M
authors.lastname: Meseguer
authors.affiliation: Instituto Valenciano de Infertilidad (IVI), University of Valencia, Pl. Policía Local 3, Valencia, Spain. ana.cobo@ivi.es.
authors.forename: Ana
authors.initials: A
authors.lastname: Cobo
mesh_terms: D001755:Blastocyst / Q000502:physiology; D016022:Case-Control Studies; D002482:Cellulose / Q000031:analogs & derivatives*; D015331:Cohort Studies; D003470:Culture Media; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D050498:Live Birth; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D010062:Ovulation Induction / Q000379:methods; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D016896:Treatment Outcome; D014199:Trehalose; D058989:Vitrification
chemical_list: D003470:Culture Media; D002482:Cellulose; C008079:hydroxypropylcellulose; D014199:Trehalose
keywords: Clinical outcome; Hydroxypropyl cellulose; Macromolecular supplement; Oocyte vitrification; Survival rate