title: Effect of laser zona pellucida opening on clinical outcome of assisted reproduction technology in patients with advanced female age, recurrent implantation failure, or frozen-thawed embryos.
abstract: OBJECTIVE
  To determine whether laser-assisted hatching can improve clinical outcome of assisted reproductive techniques in patients with advanced female age, with recurrent implantation failure, or who are using frozen-thawed embryos.
  
  
  METHODS
  A prospective randomized study.
  
  
  METHODS
  The infertility and IVF unit at a research facility in Iran.
  
  
  METHODS
  Four hundred ten patients with advanced female age (> or =37 y), 796 patients with recurrent implantation failure (for > or =2 cycles), and 180 patients with frozen-thawed embryos.
  
  
  METHODS
  Patients were divided equally into test and control groups. On the day of embryo transfer, the zona pellucida of the selected embryos in the test group were opened about 40 mum by using an infrared optical laser system, whereas in the control group they were all intact.
  
  
  METHODS
  Clinical pregnancy rates and implantation rates.
  
  
  RESULTS
  In the patients with advanced female age or recurrent implantation failure, the clinical pregnancy and implantation rates were similar for the test and control groups. However, in the patients with frozen-thawed embryos, the rates were statistically significantly higher in the test group as compared with those of the control group (31.2% and 12.8% vs. 11.1% and 4.2%, respectively).
  
  
  CONCLUSIONS
  The laser-assisted hatching improved the pregnancy and implantation rates in patients with frozen-thawed embryos but had no effect in patients with advanced female age or recurrent implantation failure.
authors: Department of Embryology, Infertility and IVF Unit, Royan Institute, Tehran, Iran. mr_valojerdi@yahoo.com
authors: Mojtaba Rezazadeh
authors: MR
authors: Valojerdi
authors: Poopak
authors: P
authors: Eftekhari-Yazdi
authors: Leila
authors: L
authors: Karimian
authors: Saeed Kazemi
authors: SK
authors: Ashtiani
mesh_terms: D000328:Adult; D000367:Age Factors; D015925:Cryopreservation; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D007246:Infertility / Q000628:therapy*; D007259:Infrared Rays; D007834:Lasers; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D027724:Reproductive Techniques, Assisted; D017211:Treatment Failure; D015044:Zona Pellucida / Q000528:radiation effects*