Effect of denuding on polar body position in in-vitro matured oocytes

The aim of this study was to determine whether the denuding procedure causes the polar body to move within the perivitelline space. Only those patients undergoing IVF who had unused in-vitro matured (IVM) oocytes were included in this study. IVM oocytes were initially viewed under a non-invasive, polarized light microscope. A laser was used to mark the location of the polar body on the zona. Oocytes were subjected to the denuding procedure with a 150 mu m, 135 mu m and 125 mu m diameter pipette. After each pipetting, the oocytes were viewed again to determine whether the polar body had moved. After denuding, the oocyte was left to culture overnight and viewed 24 h later. After denuding with the 150 mu m, 135 mu m and 125 mu m pipettes and after 24 h in culture, the average angle between the spindle and polar body was 15.4 +/- 10.4 degrees, 16.1 +/- 10.1 degrees, 20.9 +/- 11.7 degrees, and 26.7 +/- 18.2 degrees. respectively (P = 0.0021). Slight changes in angles were noted between denuding with the different diameter pipettes. The largest changes in angles were seen after 24 h in culture.