Zona free or Zona damaged human oocytes: experiences and indications for their rescue

Zona Pellucida (ZP) has both mechanical and active functions. Many aspects related to its participation in the fertilization process are still controversial and ZP anomalies remain a potential cause of infertility. The integrity of the female gamete is important to ensure its functions and competence. By chance, it is possible to find zona free (ZFO) or zona damaged (ZDO) oocytes caused by lack of synthesis or damages during manipulation for in vitro fertilization. This problem becomes relevant when few oocytes are retrieved or in particular clinical conditions (early meno pause, severe endometriosis, oncology). Experiences and tricks to rescue these oocytes are presented in this work.