The benefit of artificial oocyte activation is dependent on the fertilization rate in a previous treatment cycle

Following intracytoplasmic sperm injection (ICSI), some patients present low or zero fertilization rates. Artificial oocyte activation has been proposed as a suitable means to overcome this problem. This study applied artificial oocyte activation in patient cohorts with a history of no fertilization (0%, group 1), fertilization between 1 and 29% (group 2) or fertilization between 30 and 50% (group 3) in initial ICSI cycles. In the following treatment cycles, oocytes were activated after ICSI using calcium ionophore. Fertilization, pregnancy and take-home baby rates were compared with the previous cycle without activation. In group 1, fertilization rate was 41.6%, embryos for transfer were available in 82.1% of cycles, giving a clinical pregnancy rate of 18.8% and take-home baby rate of 12.8%. In group 2, despite a lower transfer rate (87.9% versus 100%, P < 0.05), there were higher fertilization and clinical pregnancy rates (44.4% versus 19.3% and 31.4% versus 12.8%, respectively, P < 0.05) and take-home baby rate was 24.1% versus 12.8%. In group 3, fertilization rates differed (56.1% versus 36.8%; P < 0.001) but all other parameters were similar. Artificial oocyte activation has great potential especially in patients showing compromised fertilization rates below 30% after standard ICSI. (C) 2012, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.