Results of direct current electrical activation of failed-to-fertilize oocytes after intracytoplasmic sperm injection

To assess the embryo formation rate after electrical activation on failed-to-fertilize oocytes after intracytoplasmic sperm injection (ICSI).A prospective, randomized, experimental study was conducted in our research laboratory at the Reproductive Medicine Unit, Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, between January and September 2004. One hundred failed-to-fertilize oocytes after ICSI were randomly assigned by stratified allocation according to oocyte grading before ICSI. Fifty unfertilized oocytes were activated with 3 consecutive 40-/microsec pulses of 1.5 kV/cm direct electrical current in buffer solution. The other 50 unfertilized oocytes, composing the control group, were treated in same way but without electrical activation. The embryo formation rates between the groups were compared.Embryo formation rates in the electrically activated group were 80% as compared with 16% in the control group (p0.001).Failed-to-fertilize oocytes after ICSI seem to be able to resume embryonic development after electrical activation.