A protein has been identified as the reason why endometriosis causes infertility, according to a new study.
In the paper, published in Science Translational Medicine, US and South Korean researchers investigated the link between endometriosis and infertility. In endometriosis, womb-lining tissue grows outside of the uterus, often on the ovaries and fallopian tubes. This can lead to chronic pain and is associated with infertility, but the reason has been unclear, as the problem occurs outside the uterus.
Lead author Dr Jae-Wook Jeong explained the importance of the research: 'Around ten percent of women have endometriosis and up to 50 percent of endometriosis patients have infertility.'
The scientists compared endometrial tissue from 21 women with endometriosis and infertility with samples from unaffected women. They observed that levels of a protein called histone deacetylase 3 (HDAC3) were lower in the affected women. Previously developed animal models of endometriosis in mice and baboons supported this finding.
The team then developed mice unable to produce HDAC3 in uterine cells, all which were infertile. Dr Jeong and his colleagues were able to show that HDAC3 is necessary for embryo to implant in the womb. Follow-up experiments with human endometrial cells cultured in vitro showed that HDAC3 is a crucial part of the process where changes to occur in the uterus, in preparation for and during pregnancy.
This study could help endometriosis patients and their doctors select more effective treatments and enable a better understanding of female infertility.
Dr Linda Giudice, a reproductive endocrinologist at the University of California, San Francisco, who was not involved in the study said: 'The new work brings scientists a step closer to understanding what’s driving infertility in women with endometriosis. Such research could potentially offer ways to improve these women’s ability to become pregnant.'