title: From oocyte to baby: a clinical evaluation of the biological efficiency of in vitro fertilization.
abstract: OBJECTIVE
  To assess the real biological efficiency of assisted reproduction technology (ART) cycles by using a new metric called oocyte to baby rate, where live babies born (LBB) are reported in relation to the number of oocytes retrieved and used.
  
  
  METHODS
  Retrospective analysis of clinical and embryological database.
  
  
  METHODS
  University center.
  
  
  METHODS
  Patient's cycles (n = 572) divided by age (<35, 35 to 37, 38 to 40, 41 to 42, >42 years) and by oocyte donors.
  
  
  METHODS
  None.
  
  
  METHODS
  Total number of oocytes collected, the number of embryos transferable (fresh and frozen) and corresponding oocyte to LBB rates. In patients with remaining frozen embryos, the final LBB was estimated according to our reported rates.
  
  
  RESULTS
  A total of 572 oocyte retrievals yielded 7213 oocytes. The total number of transferred and frozen embryos was 2252 (a utilization rate of 31.2%). The LBB from fresh embryo transfers was 262 with an additional 64 LBB expected from frozen embryos. The overall oocyte to LBB rate was 4.6% (326 babies born). When analyzed by groups, the oocyte to baby rate was best in donor oocyte cycles (6.8%), and declined to 1% for patients >40. There was no increase in oocyte to LBB if >15 oocytes were obtained.
  
  
  CONCLUSIONS
  During ART cycles, only approximately 5% of fresh oocytes produce a baby. The time has come to investigate new methods of oocyte viability assessment and consider changing current ART practice to recruit fewer oocytes.
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, Yale Fertility Center, New Haven, Connecticut 06511, USA. pasquale.patrizio@yale.edu
authors.forename: Pasquale
authors.initials: P
authors.lastname: Patrizio
authors.forename: Denny
authors.initials: D
authors.lastname: Sakkas
mesh_terms: D000328:Adult; D019924:Embryo Disposition / Q000706:statistics & numerical data; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D007231:Infant, Newborn; D018587:Oocyte Donation / Q000706:statistics & numerical data; D054315:Oocyte Retrieval; D009865:Oocytes / Q000502:physiology*; D011247:Pregnancy; D018873:Pregnancy Rate; D011258:Pregnancy Tests; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome