Effect of fertilization by intracytoplasmic sperm injection versus conventional insemination on embryo cleavage rates

Purpose To determine if fertilization by conventional oocyte insemination vs intracytoplasmic sperm injection (ICSI) causes any difference in the maximum number of blastomeres of flesh or frozen thawed embryos transferred Methods Retrospective evaluation of all in vitro fertilization (IVF) cycles over a 10-year period in cycles having a 2 embryos transferred where the semen analysis was normal except for strict morphology which was allowed to be 2-5% normal The percentage of the maximum number of blastomeres in any transfers was compared according to the method of insemination Results There were no differences in the maximum blastomere numbers in cycles where there was conventional insemination vs ICSI Conclusions Though higher pregnancy rates have been found following the transfer of embryos derived from conventional oocyte insemination vs ICSI. and higher pregnancy rates were found following single embryo day 3 transfers with embryos with mole blastomeres. the beneficial effect of conventional insemination does not seem to be related to forming embryos with more rapid cleavage