Successful rescue activation of unfertilized oocytes with calcium ionophore (A23187) in a case of recurrent ICSI fertilization failure: A case report

Abstract

Rationale: This case report describes a couple with recurrent fertilization failure despite undergoing multiple cycles of intracytoplasmic sperm injection (ICSI). The principal clinical concern was suspected oocyte activation deficiency (OAD), in which fertilization is impeded due to the oocyte’s inability to initiate embryogenesis, commonly attributed to inadequate intracellular calcium (Ca²⁺) release following sperm injection.

Patient concerns: The couple repeatedly experienced complete or near-complete fertilization failure in previous ICSI cycles, raising suspicion of an underlying oocyte activation defect.

Diagnosis: Based on the repeated absence of fertilization post-ICSI and clinical history, a diagnosis of suspected OAD leading to recurrent ICSI fertilization failure was considered.

Interventions: Artificial oocyte activation (AOA) using the calcium ionophore A23187 was performed. After ICSI, unfertilized oocytes were exposed to the ionophore to induce Ca²⁺ influx, simulating physiological calcium oscillations essential for oocyte activation. The efficacy of intervention was evaluated through subsequent embryonic development, morphological grading, and chromosomal integrity.

Outcomes: Following AOA treatment, successful oocyte activation occurred, resulting in the formation of high-grade embryos with normal developmental progression. Chromosomal analysis revealed no detectable abnormalities, indicating genomic stability.

Lessons: Calcium ionophore-mediated AOA may serve as an effective adjunct in cases of recurrent ICSI failure attributed to OAD. This case highlights the importance of individualized therapeutic strategies in assisted reproduction; however, further research is needed to refine protocols, validate broader clinical efficacy, and assess long-term safety, including potential epigenetic risks.

Keywords

Oocyte activation deficiency / Intracytoplasmic sperm injection / Artificial oocyte activation / Calcium ionophore A23187 / Fertilization failure / Assisted reproductive technology

Conflict of interest statement

The authors declare that they have no conflict of interest.

Funding

The authors received no extramural funding for the study.

Authors’ contributions

Akash More, Vilas Chimurkar, Namrata Choudhary, Dipali More, and Sanket Mahajan were involved in clinical evaluation, patient management, and collection of relevant clinical data. They contributed to the interpretation of findings and drafting of the case report. All authors participated in critically revising the manuscript for its intellectual content. All authors approved the final version of the manuscript for publication.

Publisher’ s Note

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