The dependence of the ploidic status of embryos on the state of the spindle of oocyte division, assessed using polarization microscopy in IVF programs in women with ovarian endometriosis

Objective. In infertile women with and without ovarian endometriosis, according to preimplantation genetic testing for aneuploidy, the ploidic status of embryos generated from mature oocytes (MII oocytes) with and without a visually detectable division spindle should be clarified. Material and methods. Using the polarizing optical system OCTAX PolarAID, the state of the division spindle was studied in 345 mature oocytes of women younger than 36 years with healthy gonads (control group) and in 219 mature oocytes of women of the same age suffering from ovarian endometriosis (main group). The influence of the presence/absence of a division spindle in MII oocytes on the frequency of their correct fertilization, blastulation and the ploidic status of the resulting embryos was evaluated. Preimplantation genetic testing for aneuploidy was performed by Next Generation Sequencing (NGS). Results. In the cohort of blastocysts that were obtained from MII oocytes with an unvisualized fission spindle, the frequency of embryonic aneuploidy was 2—3 times higher than among embryos generated from mature oocytes with a normal fission spindle state. This pattern was reliable and manifested itself to the same extent in women with and without ovarian endometriosis. Conclusion. When performing the embryological stage of IVF programs in women with ovarian endometriosis and the normal state of the gonads, it is advisable to clarify, using polarization microscopy, the presence of a division spindle in all isolated adult oocytes and subsequently check for aneuploidy using pre-implantation genetic testing, all blastocysts generated from eggs with a visually undefined division spindle.