Comparative Analysis of the Spindle of Fresh In Vivo-Matured Human Oocytes Through Polarized Light and Confocal Microscopy: A Pilot Study.

BACKGROUND

Considering the scarcity of literature data about the predictive capacity of polarization microscopy (PM) in identifying meiotic normality in human in vivo-matured oocytes, the main objective of the present study was to determine whether qualitative analysis of the spindle through PM can predict meiotic normality in fresh in vivo-matured human oocytes.

METHODS

Infertile patients undergoing controlled ovarian stimulation to intracytoplasmic sperm injection (ICSI) were selected. Fresh in vivo-matured oocytes were evaluated by PM and, immediately afterward, fixed for confocal microscopy (CM) analysis for evaluation of the spindle and chromosome distribution. We evaluated the percentage of oocytes with meiotic normality and abnormality determined by CM among oocytes with visible and nonvisible spindle and between oocytes with the spindle located at 0° to 60° angle to the first polar body (PB; normal position) and at 60° to 90° angle to the first PB (risky position) according to PM.

RESULTS

From 23 patients, 73 oocytes were analyzed. There were no significant differences in the percentage of oocytes with meiotic abnormalities among oocytes with visible and nonvisible spindles and among oocytes with the spindle in the normal and risky positions.

CONCLUSIONS

Under the conditions tested, qualitative evaluation of the spindle through PM is not consistent with CM analysis and has limited predictive value of meiotic normality in fresh in vivo-matured human oocytes, which needs to be confirmed in larger studies. Our findings make questionable the usefulness of this methodology as a tool for noninvasive oocyte selection for ICSI.