Endometriosis is a rather mysterious and unique type of condition among women. It affects 10 to 15% of women of childbearing age, causing either pain or fertility problems, or even both. The work of Michelle Nisolle, professor at the University of Liège and head of the gynaecology and obstetrics Unit, focuses on the conditions that contribute to the development of the disease and the possibilities of treating the symptoms developed by the women who suffer from it. “While it’s a benign condition, it nevertheless has the same characteristics as a cancerous tumour, only it isn’t life-threatening”, Michelle Nisolle immediately explains. “But its impact on quality of life can be similar to that caused by cancer, causing pain, infertility, etc.”

Before delving into the depths of the research carried out at ULg on this unique disease, let’s take a quick look at its clinical background. Endometriosis particularly affects young women, sometimes as early as puberty, but most often between the ages of 25 and 40. In simple terms, the endometrial cells shed by the uterus attach themselves to tissue outside the uterus, most often in the pelvic cavity, on the ovaries or in the rectum, or more rarely in more distant locations (lungs, brain, etc.). Typical symptoms are usually intense pain in the lower abdomen during menstruation. This is because the endometriosis lesions are subject to the same hormonal influences as the endometrium and during menstruation, these cells are also subject to bleeding and inflammation. But since there is no way for this ‘menstrual flow’ to leave the body, the blood and the sloughed off endometrial cells flow into the pelvic cavity and irritate the peritoneum, causing the above-mentioned pain.

That’s it for ‘regular’ endometriosis. The problem is, the process doesn’t stop there. Because the presence of these ectopic tissues leads to the development of cysts, adhesions and fibrotic reactions, they also cause pain, and can hamper the normal process of fertilisation, which ultimately results in infertility.

These symptoms are closely linked with the location of the lesions: if they are on the bladder, they cause pain during urination (dysuria), on the rectum, they cause profound pain during defecation (dyschezia), and on the vagina, they are responsible for pain during sexual intercourse (dyspareunia). As for fertility problems, they are essentially linked to the presence of cysts on the ovaries. These can range from the size of a pinhead to the size of a grapefruit in diameter and are filled with a chocolate-coloured fluid, made up of decomposed blood. When they are large in size, these cysts disrupt the whole architecture of the pelvic cavity, often putting the ovaries out of reach of the fallopian tubes which, under normal circumstances, would carry the fertilised eggs to the uterus. But it is thought that through a less well understood mechanism, endometriosis can also alter the peritoneal environment resulting in the rapid inactivation of sperm.