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.
© 2020 Royal College of Obstetricians and Gynaecologists.