title: Laser-assisted hatching of embryos is better than the chemical method for enhancing the pregnancy rate in women with advanced age.
abstract: OBJECTIVE
  Assisted hatching may enhance embryo implantation. This study was conducted to examine the efficacy of the laser- and chemical-assisted hatching for promotion of implantation (IR), pregnancy (PR), and delivery rate (DR) in older women undergoing IVF cycles.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  An IVF unit of a medical center.
  
  
  METHODS
  A total of 601 embryos from 141 women aged > or =38 years underwent controlled ovarian hyperstimulation (COH) and assisted hatching.
  
  
  METHODS
  The study population was divided into two groups: group 1 had laser-assisted hatching (n = 85) and group 2 had chemical-assisted hatching (n = 56). Before the transfer, the day 3 embryos were hatched by using a 1.48-microm noncontact diode laser or acid Tyrode's solution.
  
  
  METHODS
  The IR, PR, and DR between the groups were compared.
  
  
  RESULTS
  There were no statistical differences between groups in age, E2 concentrations during hCG administration, gonadotrophin dosage, embryo grade, the numbers of oocytes retrieved, oocytes fertilized, and embryos transferred. Higher IR, PR, and DR were noted in the laser-assisted hatching group. The IR, PR, and DR were: group 1, 8.2%/31.8%/24.7% and group 2, 3.8%/16.1%/10.7%, respectively.
  
  
  CONCLUSIONS
  Laser-assisted hatching of embryos is more effective than the chemical method in enhancing the IR and PR of women with advanced age. The laser system allows an easier, faster, and safer micromanipulation of the zona pellucida, which provided a better method in zona drilling.
authors.affiliation: Department of Obstetrics and Gynecology, China Medical College Hospital, Taichung, Taiwan.
authors.forename: Yao-Yuan
authors.initials: YY
authors.lastname: Hsieh
authors.forename: Chun-Chia
authors.initials: CC
authors.lastname: Huang
authors.forename: Tzu-Chun
authors.initials: TC
authors.lastname: Cheng
authors.forename: Chi-Chen
authors.initials: CC
authors.lastname: Chang
authors.forename: Horng-Der
authors.initials: HD
authors.lastname: Tsai
authors.forename: Maw-Sheng
authors.initials: MS
authors.lastname: Lee
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D036861:Delivery, Obstetric / Q000706:statistics & numerical data; D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000187:drug effects / Q000528:radiation effects*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007552:Isotonic Solutions / Q000627:therapeutic use; D053685:Laser Therapy; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D011677:Punctures / Q000379:methods*
chemical_list: D007552:Isotonic Solutions; C037692:Tyrode's solution