title: Influence of patient age on the growth and transfer of blastocyst-stage embryos.
abstract: OBJECTIVE
  To examine the effects of patient age on the growth and transfer of blastocyst-stage embryos.
  
  
  METHODS
  Retrospective clinical study.
  
  
  METHODS
  Private assisted reproductive technologies center.
  
  
  METHODS
  Three hundred patients between the ages of 18 and 45 undergoing in vitro fertilization.
  
  
  METHODS
  Bipronucleate oocytes were grown for up to 144 hours and subsequently transferred when at least one embryo attained the expanded blastocyst stage.
  
  
  METHODS
  Oocytes retrieved and fertilized, blastocyst formation rates, implantation rates, and pregnancy rates per retrieval and transfer.
  
  
  RESULTS
  The rate of cycle cancellation before oocyte retrieval increased significantly with age, and the average number of oocytes per retrieval declined significantly with age. Fertilization rates were unrelated to patient age. The proportion of cycles with expanded blastocysts declined significantly with age. Pregnancy rates per stimulation declined with age, but pregnancy rates per transfer were approximately 50% across the entire age range studied.
  
  
  CONCLUSIONS
  The decline in female fertility with age appears to be the result of reduced numbers of oocytes and the inability of fertilized oocytes to develop to the blastocyst stage. Implantation and pregnancy rates appear to be unaffected by age when blastocysts do form.
authors.affiliation: Fertility Center of Las Vegas, Las Vegas, Nevada 89117, USA. bsshapiro@aol.com
authors.forename: Bruce S
authors.initials: BS
authors.lastname: Shapiro
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Richter
authors.forename: Dee C
authors.initials: DC
authors.lastname: Harris
authors.forename: Said T
authors.initials: ST
authors.lastname: Daneshmand
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging; D001755:Blastocyst / Q000502:physiology*; D002452:Cell Count; D046508:Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D009865:Oocytes; D011247:Pregnancy; D012189:Retrospective Studies; D020858:Tissue and Organ Harvesting; D016896:Treatment Outcome