O-11: Zona Pellucida Birefringence and Meiotic Spindle Visualization of Human Oocytes Are Not Influenced by In Vitro Maturation Technology

Background: In vitro maturation (IVM) is a promising treatment option for certain infertile women. Nowadays, with the aid of the Polscope, it has become possible to evaluate zona pellucida (ZP) and spindle as parameters of oocyte quality. The goal was to investigate the relationship between the presence of the meiotic spindle and ZP birefringence with morphology of the in vivo and in vitro matured human oocytes. Materials and Methods: The oocytes were obtained from stimulated ovaries of patients undergoing ICSI (intra cytoplasmic sperm injection). Germinal vesicles (GV; n=47) and metaphase I (MI; n=38) oocytes underwent in vitro maturation (IVM) using maturation medium supplemented with FSH+LH. They were checked for maturity 24-40 hours after culture. With aid of Polscope, the presence of spindles and ZP birefringence were assessed in both in vivo (n=56) and in vitro (n=56) matured oocytes. In addition, the morphology of each matured oocyte was evaluated using inverted microscope. The morphologic characteristics of oocytes were categorized to intracytoplasmic and extracytoplasmic abnormalities. Results: The rate of IVM in GV and MI oocytes was 59.6% and 73.7%, respectively (p=0.25). There were insignificant differences for ZP birefringence and meiotic spindle between the in vivo and in vitro MΙΙ (metaphase ΙΙ) oocytes. In sub-analysis, the rates of morphologically abnormal oocytes had no significant differences between two groups, except for irregular shape (p=0.001), refractile body (p=0.001) and fragmented polar body (p=0.03), which were higher in in vitro matured oocytes. In in vivo matured oocytes, the oocytes with intracytoplasmic and both abnormalities showed significantly higher low birefringent ZP (p=0.007and p=0.02, respectively). There was no relationship between the morpho-abnormality of oocytes and spindle detection. Conclusion: Clinical IVM is a safe technology for keeping the maturation and integrity of oocytes high. Also, application of non-invasive Polscope is recommended in IVM program for detection of the most suitable oocytes for ICSI.