A retrospective analysis of artificial oocyte activation in patients with low or no fertilisation in intracytoplasmic sperm injection cycles.

Intracytoplasmic sperm injection (ICSI) is commonly used to treat severe male factor infertility in assisted reproduction. A small percentage of patients face suboptimal fertilisation rate or even fertilisation failure despite having ICSI. Artificial oocyte activation (AOA) has been proposed as a suitable method to overcome their problem. This is a retrospective cohort analysis of ICSI cycles undergoing AOA. Injected metaphase II oocytes were exposed to either calcium ionophore (A23187) after ICSI or injection of calcium chloride during ICSI followed by incubation with A23187 after ICSI. The previous ICSI cycles of the patients formed the historical control group. Thirty-four AOA cycles were analysed. The normal fertilisation rate (52.1%) was significantly improved in the AOA group. The percentage of failed fertilisation cycles (11.8%) were significantly reduced in the AOA group. The cumulative clinical pregnancy rate (47.1%) and live birth rate (29.4%) were significantly increased when compared to the previous cycles. Subgroup analysis revealed that the performance of the A23187 only protocol and the concomitant injection of calcium chloride protocol were comparable in terms of laboratory parameters and pregnancy outcomes. AOA is an effective method to improve the fertilisation rate and pregnancy outcome of infertile couples with previous fertilisation problem after ICSI.IMPACT STATEMENTWhat is already known on this subject? A failed and low fertilisation rate after ICSI is not uncommon in assisted reproduction. AOA is normally used to improve fertilisation but there are discrepancies in the efficacy of the treatment.What do the results of this study add? AOA improves the fertilisation rate and pregnancy outcomes of couples with suboptimal fertilisation rate and fertilisation failure in previous ICSI cycles. The efficacies of two AOA protocols were comparable. The A23187 only protocol was recommended because of its simplicity.What are the implications of these findings for clinical practice and/or further research? AOA should be considered as a routine procedure for infertile couples with compromised fertilisation rates in previous ICSI cycles.

Phasing-in of vitrification into routine practice: why, how, and what.

OBJECTIVE: To evaluate and compare the laboratory and clinical outcomes of vitrification with slow-freezing method for cryopreservation of embryos and blastocysts in an in-vitro fertilisation programme. DESIGN: Retrospective analysis of all the 104 cycles of frozen embryo and blastocyst replacements from 2003 to 2008 and all the 149 cycles with embryos or blastocysts for vitrification from 2006 to 2009. SETTING: Hospital-based Licensed Assisted Reproduction Treatment Centre in Hong Kong. PARTICIPANTS: All participants having frozen embryos or blastocysts transfer from 2003 to 2008. INTERVENTIONS: Surplus embryos and blastocysts after fresh transfer were cryopreserved by vitrification method. MAIN OUTCOME MEASURES: Cryosurvival rate after freeze-thawing of early cleavage embryos and blastocysts by the two cryopreservation methods of slow-freezing and vitrification, and the pregnancy rate, implantation rate, delivery rate and live-birth rate achieved. RESULTS: Cryosurvival rates of both vitrified blastocysts (79%) and early cleavage-stage embryos (88%) were significantly higher, as compared with the slow-freezing groups (57% and 72% respectively, both P<0.05). Pregnancy rates, delivery rates, and implantation rates were all significantly higher with vitrification regardless of the embryo types. Both implantation and live-birth rates were higher (31%, odds ratio=14 and 27%, odds ratio=11, respectively) per vitrified blastocyst transferred as compared with slow-freezing (both 3%). CONCLUSION: Vitrification improved clinical outcomes of both frozen embryos and especially blastocyst transfers. It conferred upon both blastocysts and embryos better developmental potential after the vitrify-thaw procedure.