Endometriosis and infertility: deciding between surgery and IVF

Endometriosis is tissue similar to the womb lining growing outside the womb. The mechanisms behind its effect on fertility are not fully understood. Scarring may distort the pelvis and tubes, cysts on the ovary may reduce the number and quality of eggs, inflammation may affect eggs, sperm and embryos, and pain can reduce how often intercourse happens. The NHS lists endometriosis among causes of infertility through damage to the ovaries or tubes.

Reassuringly, Endometriosis UK reports that many people with endometriosis do conceive naturally, and the figure it gives is approximately 60 to 70 per cent, though the effect differs greatly between individuals and with the stage of disease.

The HFEA says mild endometriosis found during keyhole surgery can be treated by destroying it with heat, and that more extensive disease may warrant removal of tissue. It stresses that the decision is individual, and that surgery is not guaranteed to restore fertility. It also advises trying to conceive naturally for a period after tubal surgery before moving to IVF and reminds patients of the ectopic pregnancy risk after tubal surgery.

Endometriosis UK notes improved pregnancy rates after laparoscopic treatment of superficial disease but limited research for deep endometriosis involving the bowel, bladder or ureter. For deep disease, surgery is often driven by pain and organ function, and fertility benefit is less certain.

• Pain that is severe and unresponsive to other treatments.

• Suspected tubal damage or adhesions that block egg pick-up.

• Large ovarian endometriomas causing symptoms.

• Younger age with good ovarian reserve and a partner with normal sperm.

IVF bypasses the pelvic problems and is often advised when a woman is older, when ovarian reserve is already low, when a partner has sperm abnormalities, when there has been previous surgery for endometriosis, or when time is short. The HFEA lists blocked or damaged tubes and unexplained fertility problems among reasons IVF is recommended. The NHS adds that local integrated care boards decide who is funded.

Repeated surgery on the ovaries for endometriomas can reduce ovarian reserve, because healthy tissue may be removed along with the cyst. For this reason many specialists avoid operating on endometriomas purely to improve fertility when IVF is the planned route, unless symptoms or access to follicles demand it. This is a clinical judgement for each case.

Because the choice can be finely balanced, patients benefit from a multidisciplinary conversation in which a gynaecologist who operates on endometriosis and a fertility specialist both contribute.

• How extensive is the disease on scans or previous surgery?

• What is my ovarian reserve and how might it change with time?

• Are my tubes open?

• Is my partner sperm result normal?

• Will surgery relieve pain even if it does not change fertility?

• What are the risks of the operation for my ovaries and bowel?

Endometriosis UK reports that pain tends to improve during pregnancy but may return afterwards, that pregnancy does not cure the condition, and that miscarriage and ectopic pregnancy are somewhat more common than in the general population, the latter more than doubling relative to the general risk. These figures are population-level and a personal risk should be discussed with your obstetric team.

Because hormonal treatments such as the pill or coil work by suppressing ovulation, they are paused when trying to get pregnant, as the NHS notes. Simple pain relief, heat, pelvic physiotherapy and psychological support remain available. The NHS also lists referral to a fertility specialist when pregnancy is not occurring.