title: Randomized controlled study of human zona pellucida dissection using the zona infrared laser optical system: evaluation of blastomere damage, embryo development, and subsequent hatching.
abstract: OBJECTIVE
  To assess the effect of laser hatching on human embryo damage and subsequent development using the Zona Infrared Laser Optical System (ZILOS).
  
  
  METHODS
  Randomized controlled study.
  
  
  METHODS
  Tertiary care fertility clinic.
  
  
  METHODS
  One hundred fourteen donated and discarded frozen human embryos.
  
  
  METHODS
  Embryos were thawed, cultured with cleavage and morphology evaluated periodically, and randomized into control, partial hatching, or complete hatching groups. The laser hatching procedure was performed by ZILOS. Zona thickness and embryo diameter were recorded. Complete hatching involved the production of a full-thickness defect in the zona and partial hatching, a defect in the outer half of the zona. No laser treatment was administered to the control group.
  
  
  METHODS
  Blastocyst development and completion of hatching process.
  
  
  RESULTS
  No significant difference was noted between the three study groups for their baseline characteristics. There was no significant difference in blastocyst development among the three groups. However, the complete hatching group showed a significant increase in hatching compared to the control group.
  
  
  CONCLUSIONS
  Complete laser hatching of human embryos using the ZILOS does not have an adverse effect on subsequent development and increases the rate of completion of hatching.
authors: Department of Obstetrics and Gynecology, The Howard and Georgeanna Jones Institute for Reproductive Medicine, Norfolk, Virginia 23507, USA. wongbc@evms.edu
authors: Benjamin C
authors: BC
authors: Wong
authors: Catherine A
authors: CA
authors: Boyd
authors: Susan E
authors: SE
authors: Lanzendorf
mesh_terms: D001757:Blastomeres / Q000473:pathology*; D004210:Dissection; D004622:Embryo, Mammalian / Q000502:physiology*; D005314:Embryonic and Fetal Development; D005260:Female; D006801:Humans; D007259:Infrared Rays; D053685:Laser Therapy; D015044:Zona Pellucida