Endometriosis fertility index for predicting non-assisted reproductive technology pregnancy after endometriosis surgery: a systematic review and meta-analysis

BJOG. 2020 Jun;127(7):800-809. doi: 10.1111/1471-0528.16107. Epub 2020 Feb 19.


Background: Results of studies that have assessed the accuracy of the endometriosis Fertility Index (EFI) for predicting non-assisted reproductive technology (ART) pregnancy are inconsistent.

Objective: We intended to evaluate the accuracy of EFI for the prediction of non-ART pregnancy.

Search strategy: Embase, Medline, Scopus and Web of Science were searched up to 5 October 2019.

Selection criteria: We included studies that used EFI to predict non-ART pregnancy in women with surgically documented endometriosis.

Data collection and analysis: A total of 5547 studies were identified, from which we included 17 studies on 4598 women in the meta-analysis. Eight studies were classified as good quality, and the rest were considered to be of fair quality. Only five (29.41%) studies used appropriate approaches to account for potential confounders. Pooled effect sizes with corresponding 95% CI were calculated using random-effects model.

Main results: The cumulative non-ART pregnancy rate at 36 months was 10% (95% CI: 3, 16%; P < 0.001) for women with an EFI of 0-2, which significantly increased to 69% (95% CI: 58, 79%; P < 0.001) for women with an EFI of 9-10. Compared with women with an EFI of 3-4 (18%, 95% CI: 12, 24%; P < 0.001), the combined cumulative non-ART pregnancy rates were 44% (95% CI: 26, 63%; P < 0.001) for women with an EFT of 5-6 and 55% (95% CI: 47, 64%; P < 0.001) for women with an EFI of 7-8. Paired comparison by the chi-square test showed a significant difference between all categories (P < 0.001). The odds ratio (OR) for EFI was 1.33 (95% CI: 1.17, 1.49, P < 0.001) and the summary area under the curve (AUC) was 72% (95% CI: 65, 80%, P < 0.001).

Conclusion: The current findings highlighted the good performance of the EFI score in predicting the non-ART pregnancy rate. However, these findings should be considered with caution because of the substantial heterogeneity between studies.

Tweetable abstract: Review findings show the merits of Endometriosis Fertility Index as having a prognostic ability for non-assisted reproductive technology pregnancy.

Keywords: Endometriosis Fertility Index; meta-analysis; pregnancy; systematic review.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Adult
  • Area Under Curve
  • Endometriosis / complications*
  • Endometriosis / physiopathology
  • Endometriosis / surgery
  • Female
  • Fertility
  • Gynecologic Surgical Procedures / adverse effects*
  • Humans
  • Infertility, Female / etiology*
  • Odds Ratio
  • Postoperative Complications / etiology*
  • Postoperative Period
  • Predictive Value of Tests
  • Pregnancy
  • Pregnancy Rate
  • Prognosis
  • Risk Assessment / methods*