title: Effect of the size of zona pellucida opening by laser assisted hatching on clinical outcome of frozen cleaved embryos that were cultured to blastocyst after thawing in women with multiple implantation failures of embryo transfer: a retrospective study.
abstract: OBJECTIVE
  To evaluate the effect of the size of zona pellucida opening by laser assisted hatching for frozen cleaved embryo that were thawed after both fresh and frozen cleaved embryo transfer cycles failed and were cultured to blastocyst after thawing in patients with multiple implantation failures.
  
  
  METHODS
  Of 101 consecutive procedures (October 2003 to June 2006), 30 patients declined to perform assisted hatching and were selected as control group, 40 patients had 40 microm opening of the zona (October 2003 to January 2005), 31 patients had 50% of the zona opening (February 2005 to June 2006).
  
  
  RESULTS
  The pregnancy, implantation and delivery rates were significantly higher in 50% opening group (74%, 52% and 65%) compared to control group (17%, 10% and 13%; P < 0.01) and 40 microm opening group (43%, 27% and 38%; P < 0.04).
  
  
  CONCLUSIONS
  The size of the zona pellucida opening may affect the outcome of frozen cleaved embryo transfer.
authors: Kinutani Women's Clinic, 8-23-4F, Hondori, Naka-ku, Hiroshima 730-0035, Japan. hiraoka@chive.ocn.ne.jp
authors: Kenichiro
authors: K
authors: Hiraoka
authors: Megumi
authors: M
authors: Fuchiwaki
authors: Kaori
authors: K
authors: Hiraoka
authors: Toshitaka
authors: T
authors: Horiuchi
authors: Tomoyo
authors: T
authors: Murakami
authors: Masayuki
authors: M
authors: Kinutani
authors: Kazuo
authors: K
authors: Kinutani
mesh_terms: D000328:Adult; D001755:Blastocyst; D002970:Cleavage Stage, Ovum; D015925:Cryopreservation; D010064:Embryo Implantation / Q000502:physiology*; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000628:therapy*; D053685:Laser Therapy; D008297:Male; D011247:Pregnancy; D012189:Retrospective Studies; D046509:Tissue Culture Techniques; D017211:Treatment Failure; D015044:Zona Pellucida / Q000502:physiology*