The Fate of Zona free Oocyte Following Intracytoplasmic Sperm Injection: A Case Report and Review of Literature.

The zona pellucida (ZP) is essential in reproductive biology, covering sperm selection, species-specific fertilisation, inhibition of polyspermy and stability of blastomeres in embryos. This case report highlights the developmental potential of a zona-free oocyte (ZFO). A 44-year-old woman produced a single oocyte, where detachment of the ZP occurred during the denudation process, leaving a ZFO. This oocyte underwent intracytoplasmic sperm injection (ICSI) and subsequent culture, developing into a four-cell embryo on the 3 day. Despite embryo transfer, no pregnancy was achieved 14 days post-transfer. This case underlines the potential for cell development in ZFOs while emphasising the challenges of achieving successful implantation.