ObGyn Intelligence
Evidence Matters
Prepare
Evidence LibraryBefore pregnancy and fertilityRisks
Evidence Library · Risks

Endometriosis and fertility

Surgery helps modestly if you are already operating. Going looking is a different decision.

Endometriosis is found in about 44% of women labelled unexplained who undergo diagnostic laparoscopy, most of it minimal or mild. So the question of whether treating it helps is not a marginal one.

The best trial randomized 341 infertile women aged 20 to 39 with minimal or mild endometriosis, all of whom were already having a diagnostic laparoscopy, either to removal of the visible lesions or to the diagnostic look alone:

Outcome over 36 weeksLesions removedDiagnostic laparoscopy only
Pregnancy continuing past 20 weeks50 of 17229 of 169
Cumulative probability30.7%17.7% (P = 0.006)
Fetal loss among recognised pregnancies20.6%21.6%

An absolute difference of about 13 percentage points, or roughly eight women operated on for one extra ongoing pregnancy. Note that both groups had surgery, so this isolates the effect of removing the lesions rather than the effect of operating at all.

The tension nobody resolves for youThat trial says removal helps if you are already inside. The fertility society's list says laparoscopy for unexplained infertility should not be ordered routinely. Both are defensible and they point in different directions.

The European guideline is unusually honest about the state of the evidence: it says that based on existing evidence, no firm recommendations could be formulated on the most appropriate treatments, and it explicitly challenges laparoscopy and histology as the diagnostic gold standard.

If you have pain as well as infertility, the calculation changes, because surgery may be worth doing for the pain on its own terms. If your only complaint is difficulty conceiving, the case for going looking is much weaker. That distinction is the one worth having explicitly with your own doctor.

Where this comes from:
40. Marcoux S, Maheux R, Bérubé S; Canadian Collaborative Group on Endometriosis. Laparoscopic surgery in infertile women with minimal or mild endometriosis. N Engl J Med. 1997;337(4):217-222.
41. Becker CM, Bokor A, Heikinheimo O, Horne A, Jansen F, Kiesel L, et al. ESHRE guideline: endometriosis. Hum Reprod Open. 2022;2022(2):hoac009.
32. Van Gestel H, Bafort C, Meuleman C, Tomassetti C, Vanhie A. The prevalence of endometriosis in unexplained infertility: a systematic review. Reprod Biomed Online. 2024;49(3):103848.
10. Practice Committee of the American Society for Reproductive Medicine. Fertility evaluation of infertile women: a committee opinion. Fertil Steril. 2021;116(5):1255-1265.

Covered in the essential classes

Continue

More from Before IVF

This page is educational. It supports the conversation with your own clinicians. It is not consent to any treatment, and it cannot assess you. If you are worried about a symptom now, see urgent warning signs.