The effect of artificial oocyte activation on embryomorphokinetic parameters and blastulation time

Artificial oocyte activation (AOA) with Calcium ionophore (Ca-I) application has been shown to improve fertilization rates in patients with poor reproductive outcomes and fertilization failure; however, the effect of Ca-I on embryomorphokinetic parameters remains unclear. The aim of this study was to evaluate the effect of AOA with Ca-I application on embryomorphokinetic parameters and clinical pregnancy outcomes. In this retrospective cohort study, a total of 412 cycles were involved and participants were classified into two groups as intracytoplasmic sperm injection ICSI + AOA (n = 225) and ICSI (n = 187). There were no significant differences between groups in terms of baseline parameters. When the duration from 2PN to tB (time to blastulation) was examined, t2, t3, t4, or t5 times were not significantly different between the groups; however, Ca ionophore application was found to extend time to start of blastulation (tsB) time and tB (p < 0.05). Optimal time-lapse parameters (t5, cc2, S2, and t5-t2) also did not differ between the two groups, and there were no significant differences in embryo grades determined by optimal time-lapse parameters. According to the fertilization and pregnancy results, no significant differences were found between the groups. In conclusion, Ca ionophore application does not seem to affect most embryomorphokinetic parameters except blastulation time, and the clinical importance of this finding needs further research.