Endometriosis can Adversely Affect Oocyte Quality

Endometriosis can Adversely Affect Oocyte Quality

When compared to oocytes collected from women with male infertility factor, oocytes from women with endometriosis were found to have more abnormalities.

Key Points


  • This study compares oocytes recovered from women with endometriosis to women with male factor infertility. The oocytes were analyzed for morphological abnormalities and fertilization 
  • There are a limited number of studies that analyze the relationship between oocyte morphology and endometriosis. Thus, this study seeks to address the aforementioned lack of information on the subject.

What’s done here?

  • A retrospective study took place in a tertiary care center.
  • Endometriosis group composed of 72 women with endometriosis that had undergone intracytoplasmic sperm injection cycles (ICSI) cycles. The male partners of the participants had normal sperm parameters, as determined by the World Health Organization criteria. The control group consisted of 60 women which underwent ICSI cycles due to male factors including abnormal sperm parameters.
  • The oocyte collection, controlled ovarian stimulation (COS), Ovulation triggering, evaluation of oocyte morphology and maturation were the same for both groups.
  • The data from the study was subject to statistical analyses.

Key results:

  • Before ICSI cycles, the researchers analyzed 1568 oocytes for morphological parameters. 775 oocytes were from the endometriosis group and 793 oocytes were from the control group.
  • There was abnormal oocyte morphology in 352 of the 1568 oocytes, 208 were from the endometriosis group and 144 were from the control group.
  • The abnormal oocytes from the endometriosis group most often had dark cytoplasm; a zona pellucida that is dark, large, or thin; and polar bodies that are flat or fragmented.
  • The results lead the researchers to believe that there is more abnormal oocyte morphology in women with endometriosis than in women who have partners with abnormal sperm parameters. Thus, endometriosis can lead to subfertility because of abnormal oocytes. This can adversely impact assisted reproductive technique (ART) results in women with endometriosis.

Limitations of the study:

  • The authors list the main limitation of the study as the retrospective design?
  • The researchers did not analyze implantation and pregnancy rates, which are other important factors in this area of study.

Lay Summary

Kasapoglu et al. recently published a study in Gynecological Endocrinology titled “Detrimental effects of endometriosis on oocyte morphology in intracytoplasmic sperm injection cycles: a retrospective cohort study.” In this paper, they compared the oocytes recovered from women who have endometriosis with women whose partners suffer from male factor infertility. The retrieved oocytes were evaluated for morphological abnormalities and fertilization outcomes.

The study consisted of 2 groups: an experimental group and a control group. The experimental group was comprised of women with endometriosis and male partners with normal sperm partners. The control group was comprised of women who had to undergo intracytoplasmic sperm injection cycles (ICSI) cycles because of male factors, which include abnormal sperm parameters. The researchers collected oocytes and use microscopy to evaluate the morphology of the aforementioned oocytes. Researchers also analyzed the ovarian response to COS.

There were 352 oocytes with abnormal morphology and 208, 59.1%, of those oocytes came from the endometriosis group. The dysmorphisms most often seen in the oocytes from the endometriosis group include dark cytoplasm; a zona pellucida that is dark, large, or thin; and polar bodies that are flat or fragmented. In conclusion, women with endometriosis were found to have significantly more oocytes defects than women who have male factor infertility. This finding may help explain the subfertility seen in endometriosis patients.

Research Source: https://www.ncbi.nlm.nih.gov/pubmed/29057690

oocyte male factor infertility ICSI ART ovulation implantation morphology Zona pellucida cytoplasm polar bodies


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