Endometriosis and infertility: current concepts

Infertility in endometriosis; could there be a therapeutic gateway in respect to the regurgitation hypothesis ?

Key Points

Highlights:

• Endometriosis induces decreased quantities of oocytes and embryos, besides causing decreased embryo quality, and decreased implantation and pregnancy rates. 

Importance:

• The use of anti-oxidant molecules against ROS-mediated oxidative damage in endometriosis is also an important aspect of on-going research.

What's done here: 

• This paper is a comprehensive review of published research in regard to infertility related in endometriosis. 

Key Results:

• One working endometriosis hypothesis is retrograde menstruation that activates macrophages to release reactive oxygen species (ROS), leading to oxidative stress. Besides via the Fenton reaction of refluxed blood, the hydroxyl radical, the most potentially destructive ROS is formed.
• ROS are generated in endometriosis tissues proximal to gametes and embryos, and adversely affect oocyte, sperm, and embryo microtubule apparatus, chromosomes, and DNA.
• Research demonstrated decreased quantity and quality of oocytes and embryos from IVF/ICSI patients with endometriosis.
• Research data also point that endometriosis causes oocyte and fetal aneuploidy through a release of ROS species.
• It seems that endometriosis may cause oocyte and fetal aneuploidy via ROS species.
• In addition, the use of anti-oxidant molecules against ROS-mediated oxidative damage is also a promising gateway to infertility treatment in endometriosis.

Lay Summary

Hungarian and US scientists have published a comprehensive review on infertility related to endometriosis in Frontiers in Endocrinology, November 2018 issue. 

Endometriosis is a common entity in women of reproductive age which often leads to infertility. Compiled research data reveal that endometriosis induces decreased quantities of oocytes and embryos, besides causing decreased embryo quality, and decreased implantation and pregnancy rates. 

IVF/ICSI patients with endometriosis have shown decreased quantity and quality of oocytes and embryos. Retrograde menstruation, a working hypothesis for endometriosis, seems to activate macrophages and release of reactive oxygen species (ROS), leading to oxidative stress. Besides refluxed blood also leads to the accumulation of most potentially destructive ROS, i.e., hydroxyl radical. Under the compilation of current research data, it is believed that endometriosis may cause oocyte and fetal aneuploidy mediated by these ROS species. ROS are also essential mediators of angiogenesis, degeneration of extracellular matrix, anti-apoptotic processes, and cellular adhesion processes participating in the formation and maintenance of endometriosis.

Anti-oxidant molecules against ROS-mediated oxidative damage in endometriosis is a promising therapeutic aspect of ongoing research in this regard. A number of antioxidants have been tested. Vitamins C and E, N-acetyl cysteine (NAC), resveratrol, and melatonin showed to reduce the numbers and sizes of endometriotic implants in experimental animal studies. NAC and other antioxidants prevent chromosome and spindle misalignments and aneuploidy in laboratory rodents.

Further research may further reveal the roles of ROS in gametic and embryonic dysfunction, aneuploidy has seen in infertility of endometriosis. Besides therapeutic regimens dedicated to reverse the effects of ROS on these aspects will continue to progress.

Research Source: https://www.ncbi.nlm.nih.gov/pubmed/30555421