title: In vitro fertilization in women age 40 and older: the impact of assisted hatching.
abstract: OBJECTIVE
  To assess the impact of assisted hatching on in vitro fertilization (IVF) outcome in women age 40 and older.
  
  
  METHODS
  A retrospective analysis was performed to compare 28 cycles of IVF without assisted hatching to 38 cycles of IVF with assisted hatching. All patients in both groups were age 40 or older and the mean age was similar.
  
  
  RESULTS
  The delivery rate per oocyte retrieval was significantly higher in the assisted hatching group (18/38; 48%) compared to the nonhatched controls (3/28; 11%, P = 0.0003). The implantation rate of hatched embryos (40/175; 22%) was clearly enhanced, compared to the nonhatched embryos (7/126; 6%, P < 0.001). The fertilization rate, number of oocytes and the number of embryos per patient were comparable in the two groups.
  
  
  CONCLUSIONS
  Assisted hatching dramatically improves embryonic implantation and term pregnancy rates in women age 40 and older undergoing IVF.
authors.affiliation: Center for Reproductive Medicine, Englewood, Colorado 80110, USA.
authors.forename: W B
authors.initials: WB
authors.lastname: Schoolcraft
authors.forename: T
authors.initials: T
authors.lastname: Schlenker
authors.forename: G S
authors.initials: GS
authors.lastname: Jones
authors.forename: H W
authors.initials: HW
authors.lastname: Jones
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D005314:Embryonic and Fetal Development / Q000502:physiology; D005260:Female; D005298:Fertility / Q000502:physiology*; D005307:Fertilization in Vitro / Q000379:methods / Q000592:standards*; D006801:Humans; D008875:Middle Aged; D009865:Oocytes / Q000502:physiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D012189:Retrospective Studies