title: [Intracytoplasmic sperm injection can improve the fertilization limitation following in vitro fertilization during previous cycles].
abstract: OBJECTIVE
  To evaluate whether or not intracytoplasmic sperm injection (ICSI) can improve previous fertilization limitation on conventional in vitro fertilization (IVF).
  
  
  METHODS
  One hundred and thirty-six completed cycles in 113 patients with ICSI treatment were grouped. Group 1 was 106 cycles perform ICSI because of male factor, and group 2 was other 30 cycles with the history of fertilization failure and fertilization rate < 20% on conventional IVF, also assembling the cycles in group 2 according to the fertilization rate.
  
  
  RESULTS
  There was no significant difference between two groups in the rates of normal fertilization(70.49% vs 72.02%), good quality embryos (38.28% vs 38.81%), and clinical pregnancy (40.57% vs 40.00%) (P > 0.05). The fertilization rate of a majority of cycles (70.00%, 21/30) in group 2 was higher than 50%, and the mean of fertilization rates was 79.79%.
  
  
  CONCLUSIONS
  ICSI can improve the fertilization limitation following IVF during previous cycles, and the fertilization rates was similar to those treated ICSI because of male factor.
authors.affiliation: Reproductive Medicine Center, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors.forename: Ling-bo
authors.initials: LB
authors.lastname: Cai
authors.forename: Ting
authors.initials: T
authors.lastname: Feng
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.forename: Yun
authors.initials: Y
authors.lastname: Qian
authors.forename: Jia-yin
authors.initials: JY
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D009865:Oocytes; D011247:Pregnancy; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic