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Assisted Gamete Treatment to Pinpoint Acquired Meiotic Maturity and Overcome Oocyte Activation Deficiency Contributed by Both Gametes

Open AccessPublished:December 29, 2022DOI:https://doi.org/10.1016/j.xfre.2022.12.006
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      Abstract

      Objective

      To treat couples with total fertilization failure (TFF) due to a combined oocyte- and sperm-related oocyte activation deficiency by optimizing oocyte response to chemical activation with calcium ionophore.

      Design

      Case report

      Setting

      Tertiary Hospital

      Patients

      Two couples with history of TFF after ICSI

      Intervention (s)

      To overcome oocyte-related OAD, extended in vivo/in vitro oocyte maturation was carried to enhance ooplasmic maturity; to address sperm-related OAD, AGT was performed to trigger oocyte activation.

      Main outcome measures

      Treatment cycle outcomes for the 2 couples undergoing ICSI with EOM and AGT.

      Results

      We identified 2 couples with TFF after ICSI due to combined factor of OAD confirmed by PLCζ expression and genomic assessment. Initial AGT treatment alone failed to enhance fertilization, suggesting superimposed oocyte dysmaturity prohibiting oocytes from responding to chemical stimuli. To address this complex form of OAD, in couple 1, 27 oocytes out of 34 retrieved presented normal metaphase II spindles after EOM; ICSI with AGT yielded a fertilization rate of 63.0% (17/27). All 17 zygotes were cryopreserved initially. Two embryos were thawed and transferred, yielding a monochorionic diamniotic twin pregnancy. Couple 2 underwent 3 ICSI cycles with EOM and AGT; 91.4% (32/35) of oocytes displayed normal metaphase II spindle and achieved an overall fertilization rate of 43.8% (14/32). A total of 12 blastocysts were cryopreserved. A single 46XY blastocyst was thawed and transferred, resulting in a singleton pregnancy.

      Conclusion

      Our study has demonstrated the usefulness of EOM by targeting spindle presence to enhance chemical responses to AGT.