Artificial oocyte activation to improve reproductive outcomes in couples with various causes of infertility: a retrospective cohort study

RESEARCH QUESTION:Does calcium ionophore treatment of oocytes improve fertilization rate, embryo development and outcomes in specific groups of infertile couples? DESIGN:This retrospective cohort study involved 796 couples undergoing oocyte activation with calcium ionophore (A23187) after intracytoplasmic sperm injection (ICSI) between 2016 and 2018. All metaphase II oocytes were exposed to 5 μmol/l ionophore for 15 min immediately after ICSI, cultured in vitro to the blastocyst stage, and transferred to the uteri of recipients on day 5 or cryopreserved for transfer in the next cycle. The previous cycles of the same patients formed the control group. RESULTS:Among 1261 ICSI cycles and 796 ICSI-artificial oocyte activation (ICSI-AOA) cycles, implantation, positive beta-HCG, clinical pregnancy and live birth rates were significantly (P < 0.05 to P < 0.001) improved for all groups, compared with previous cycles, except live birth rate in women with primary ovarian insufficiency (POI). Compared with previous cycles, rates of blastulation (all P < 0.001) and high-quality blastocysts (P < 0.05 to P < 0.001) were increased significantly for couples with male factor (oligoasthenoteratozoospermia [OAT]), unexplained infertility and couples with both factors in the ICSI-AOA cycles. High-quality blastocyst rate was increased in couples with polycystic ovary syndrome (PCOS) (P = 0.0453). Miscarriage rates were decreased significantly (P < 0.05 to P < 0.001) in couples with OAT, PCOS and unexplained infertility in the treatment cycles. No significant differences were found for fertilization rate, embryo development or live birth rate in patients with POI between both groups. CONCLUSIONS:Artificial oocyte activation was able to 'rescue' the poor reproductive outcomes in certain types of infertile couples with history of failure to achieve pregnancy.