title: Clinical application of a new assisted hatching method using a piezo-micromanipulator for morphologically low-quality embryos in poor-prognosis infertile patients.
abstract: OBJECTIVE
  To assess the effect of a assisted hatching technique using a piezo-micromanipulator on pregnancy rates in poor-prognosis infertile patients.
  
  
  METHODS
  A prospective randomized study.
  
  
  METHODS
  The Infertility and IVF unit of the Kyoto University Hospital.
  
  
  METHODS
  Infertile patients who had been treated for >4 years and failed in previous IVF trials at least twice.
  
  
  METHODS
  Two hundred forty-eight IVF cycles from 173 patients were divided into two groups: cycles with the transfer of embryos treated by assisted hatching and cycles with the transfer of nontreated embryos. Each group was subdivided into two groups according to embryo morphology: cycles in which three or two morphologically good-quality embryos were transferred and cycles in which one or no morphologically good-quality embryos were transferred. Assisted hatching was performed by a piezo-micromanipulator.
  
  
  METHODS
  The clinical pregnancy rates and implantation rates.
  
  
  RESULTS
  The clinical pregnancy and implantation rates were significantly higher in the assisted hatching group of patients with three or two good-quality embryos than in the other three groups.
  
  
  CONCLUSIONS
  The assisted hatching using a piezo-micromanipulator improved the pregnancy and implantation rates in poor-prognosis infertile patients with good-quality embryo transfer but had no effect in patients with low-quality embryo transfer.
authors.affiliation: Department of Gynecology and Obstetrics, Faculty of Medicine, Kyoto University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakayama
authors.forename: H
authors.initials: H
authors.lastname: Fujiwara
authors.forename: S
authors.initials: S
authors.lastname: Yamada
authors.forename: K
authors.initials: K
authors.lastname: Tastumi
authors.forename: T
authors.initials: T
authors.lastname: Honda
authors.forename: S
authors.initials: S
authors.lastname: Fujii
mesh_terms: D000328:Adult; D010064:Embryo Implantation; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007247:Infertility, Female / Q000628:therapy*; D008846:Micromanipulation / Q000295:instrumentation; D011247:Pregnancy; D011379:Prognosis; D011446:Prospective Studies