Endometriosis and fertility: what is the link?

A common condition

Endometriosis is the presence of tissue similar to the endometrium outside the uterine cavity. According to the World Health Organization, it affects roughly 10% of women and girls of reproductive age.

Data reported by the WHO and by reproductive medicine societies, including ESHRE, indicate that infertility is found in around 30 to 50% of the women affected. That also means half or more do not experience it.

The mechanisms put forward

Several mechanisms, often combined, are proposed to explain this link:

• chronic pelvic inflammation, unfavourable to fertilisation and implantation,
• adhesions and lesions that distort or obstruct the fallopian tubes,
• altered egg quality and ovarian reserve, particularly with endometriomas,
• pain during intercourse, which reduces its frequency.

The most characteristic symptom

Chronic pelvic pain is the most suggestive sign, especially very painful periods that resist usual painkillers and affect daily life. Pain during intercourse, on defecation or urination, and significant fatigue may be added to the picture.

Pain intensity is not proportional to the extent of the lesions: limited lesions can be extremely painful, and extensive forms almost silent.

Diagnosis cannot be improvised

Diagnosis rests on clinical examination and imaging — specialised pelvic ultrasound, MRI — and, in some situations, on laparoscopy. No questionnaire, including the one on this site, can diagnose endometriosis.

If you have suggestive pain, the only useful step is to talk to a doctor: early care improves quality of life and helps plan ahead for pregnancy.