Endometriosis and fertility

How it can affect fertility

Endometriosis can distort the anatomy of the pelvis, damage or block the fallopian tubes, and form cysts in the ovaries (endometriomas). Surgery to remove endometriomas can itself reduce ovarian reserve. The WHO estimates that a quarter to a half of women with infertility have endometriosis. Symptoms vary widely from woman to woman, and endometriosis can be present even when a pelvic examination and an ultrasound scan are normal.

Who is usually assessed

• Women with periods painful enough to disrupt daily life, deep pain during sex, or pain when opening the bowels or passing urine around the period
• Women who have difficulty conceiving, especially with those symptoms
• Anyone with an ovarian cyst that looks like an endometrioma on ultrasound
• Couples with a diagnosis of unexplained infertility whose history suggests endometriosis (see unexplained infertility)

How it is diagnosed

A careful history is the starting point. NICE recommends a transvaginal ultrasound for anyone with suspected endometriosis, to look for endometriomas and deep disease; a specialist ultrasound or MRI can map deep disease. A normal scan does not rule endometriosis out. Laparoscopy (keyhole surgery) can confirm the diagnosis, and ESHRE accepts imaging combined with a trial of treatment for pain as an alternative to a diagnostic laparoscopy.

An AMH test and an antral follicle count show the ovarian reserve, which matters when surgery is being considered (see low ovarian reserve).

Options when you are trying to conceive

• Hormonal treatments that ease endometriosis pain also stop ovulation, so guidelines advise against using them to improve fertility. NICE notes that they have no lasting effect on fertility once stopped.
• Surgery. In milder (stage I–II) endometriosis, laparoscopic removal can improve the chance of natural pregnancy. For endometriomas, NICE weighs this benefit against the possible loss of ovarian reserve; before IVF, ESHRE advises against routine surgery for endometriomas because of that loss. Surgery for deep endometriosis is a larger decision, discussed case by case. Laparoscopy is an operation under general anaesthetic and carries the risks of any operation.
• Trying naturally, IUI or IVF. NICE describes trying naturally for up to two years, or surgery, followed if needed by IUI with ovarian stimulation (up to four cycles) or IVF. ESHRE notes that IUI with stimulation may be used in milder disease, and that IVF is an option especially when the tubes are affected. Stimulation raises the chance of twins and of ovarian hyperstimulation; see IUI and IVF and ICSI.
• Fertility preservation. With extensive ovarian endometriosis, egg or embryo freezing may be discussed, although its real benefit is not yet known.

Age, ovarian reserve, symptoms, how long you have been trying and any sperm factors all shape the choice.