Endometriosis is a disease in which the lining of the womb (endometrial tissue) grows outside the womb. The condition causes menstrual pain and reduces a woman's fertility.
Women who use IVF or intra cytoplasmic sperm injection (ICSI) to circumvent sub-fertility are less likely to become pregnant if they have endometriosis, compared with women whose subfertility is due to problems with their fallopian tubes. It appears that endometriosis influences egg development and prevents the ovaries producing viable eggs. Treating women with GnRH agonists can reduce the extent of endrometriosis.
By conducting a systematic review of literature, Review Authors found that giving GnRH agonists to women with endometriosis for three to six months prior to fertility treatment produces more than a four-fold increase in the chance of becoming pregnant. "The chances of having a live birth are also increased, though currently the data is not strong enough to show how great that increase is," says lead author Professor Hassan Sallam, who works in Obstetrics and Gynaecology in Alexandria University, Egypt.
"At the moment there is no data showing whether the treatment leads to better eggs or better acceptance of embryos by the lining of the womb," says Sallam. There is also no data to show whether one particular agonist is superior to others, or whether the therapy has differential effects on women with mild or severe endometrial disease.