title: Effect of calcium ionophore on unfertilized oocytes after ICSI cycles.
abstract: BACKGROUND
  Fertilization failure is one of the most problems in assisted reproduction technology (ART).
  
  
  OBJECTIVE
  The aim of this study was the evaluation of oocytes activation by addition of calcium ionophore in unfertilized oocytes in ICSI cycles.
  
  
  METHODS
  This study was done on 15 ICSI cycles (stimulated with standard long protocol). Mature retrieved oocytes with normal morphology that had no evidence of fertilization 24 hours after ICSI were included in the study. The oocytes with fertilization and unfertilized oocytes with degeneration were excluded from the study. The unfertilized oocytes were washed with GIVF medium and were transferred to GIVF medium that contained 5 µmol of calcium ionophore and were incubated for 10 minutes. Then again oocytes were washed with GIVF medium and consequently were transferred to GIVF medium and were incubated at 37°C in 6% CO2. After 18 hours, the oocytes were examined and activated oocytes were defined with observation of at least one pronucleus or cleaved oocytes.
  
  
  RESULTS
  After ovarian stimulation and oocytes retrieval, 175 mature oocytes were obtained and injection of sperm was done for all of them. 114 of 175 oocytes (66%) showed evidence of fertilization after 24 hours. A total of 61 oocytes (34%) showed no evidence of fertilization and 10 oocytes were degenerated and were excluded from the study. Only 51 unfertilized oocytes with normal morphology were selected and were exposed to calcium ionophore. 37 (72.5%) of treated oocytes were fertilized (2PN) and 32 (62.7%) of them showed evidence of cleavage. 6 (11.8%) embryos had good quality.
  
  
  CONCLUSIONS
  According to our results, oocytes activation with calcium ionophore had an acceptable fertilization rate, however high quality embryos remained low. We propose future studies to evaluate embryo quality.
authors.affiliation: Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Eftekhar
authors.affiliation: Department of Obstetrics and Gynecology, Zanjan University of Medical Sciences, Zanjan, Iran.
authors.forename: Farnaz
authors.initials: F
authors.lastname: Mohammadian
authors.affiliation: Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Fariba
authors.initials: F
authors.lastname: Yousefnejad
authors.affiliation: Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Parisa
authors.initials: P
authors.lastname: Khani
authors.affiliation: Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Aflatoonian
keywords: Calcium ionophore; ICSI cycles; Unfertilized oocytes