title: Hyaluronan-enriched transfer medium in cleavage-stage frozen-thawed embryo transfers increases implantation rate without improvement of delivery rate.
abstract: OBJECTIVE
  To investigate the efficacy of hyaluronan-enriched transfer media in cleavage-stage frozen embryo transfer cycles.
  
  
  METHODS
  Two commercially available transfer media were prospectively compared in an observational study.
  
  
  METHODS
  Hospital-based in vitro fertilization clinic.
  
  
  METHODS
  Patients (n = 425) undergoing frozen-thawed embryo transfer (FET). The embryos transferred were included in either a study group (high hyaluronic acid [HA], n = 199) or a control group (low HA, n = 226).
  
  
  METHODS
  Delivery rate per FET; positive hCG rate, biochemical pregnancy rate, clinical pregnancy rate, implantation rate, and clinical abortion rate were secondary outcomes.
  
  
  RESULTS
  The use of HA in the transfer media significantly increased the positive hCG rate (37.2% vs. 25.2%) and implantation rate (23.1% vs. 15.8%) without increasing the delivery rate (21.6% vs. 21.2%). More subjects in the study group with a positive hCG test experienced biochemical pregnancy (28.4% vs. 8.9%).
  
  
  CONCLUSIONS
  Addition of HA to transfer media seems to favor attachment of early embryos in FETs without increasing the delivery rate.
authors: Department of Clinical Science, Division of Obstetrics and Gynaecology, Karolinska Institutet, Stockholm, Sweden.
authors: Fredwell
authors: F
authors: Hambiliki
authors: Elisabeth
authors: E
authors: Ljunger
authors: Per-Olof
authors: PO
authors: Karlström
authors: Anneli
authors: A
authors: Stavreus-Evers
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology; D000328:Adult; D002970:Cleavage Stage, Ovum / Q000187:drug effects / Q000502:physiology*; D010064:Embryo Implantation / Q000187:drug effects*; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D006820:Hyaluronic Acid / Q000494:pharmacology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D015995:Prevalence; D011446:Prospective Studies; D012189:Retrospective Studies
chemical_list: D006820:Hyaluronic Acid