Endometriosis is a condition where the endometrial tissue (the uterine lining that sheds with each monthly period) grows outside the uterus. It is an important factor in infertility, as it can cause tubal blockages and ovulation problems.

Symptoms may include: painful periods, deep pain during penetrative sex, chronic pelvic pain, painful bowel motions or urination during menstruation. However, there may be no symptoms other than difficulty getting pregnant.

Diagnosis: Laparoscopy is used for both diagnosis and treatment if tissue is seen to be blocking the tubes. Egg freezing may be advised if surgery is required that may damage the tubes or ovaries.

Treatments: Laparoscopic surgery to remove abnormal tissue. Fertility drugs with intrauterine insemination (IUI) for mild endometriosis or in vitro fertilisation (IVF) for more severe cases.