IMPACT OF ENDOMETRIOSIS ON FERTILITY AND ASSISTED REPRODUCTIVE TECHNOLOGY OUTCOMES: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

Background: The effect of endometriosis on ovarian response and reproductive success is not always clear, and its effect on assisted reproductive technology (ART) outcomes is unclear.

Objective: To assess the effect of endometriosis on fertility and ART outcomes.

Methods: Comparative original studies of women with endometriosis and non-endometriosis controls were included. 21 reports from 20 independent parent studies were retained. Random effects models with restricted maximum likelihood estimation and Hartung–Knapp confidence intervals were used to pool risk ratios (RRs) and mean differences (MDs). Outcomes were separated according to their definitions and denominators.

Results: Four to nine studies were included in individual analyses. Endometriosis was associated with lower cumulative live birth (RR 0.84, 95% CI 0.73–0.95; I²=0.0%) and cumulative clinical pregnancy (RR 0.81, 95% CI 0.72–0.91; I²=0.0%). Women with endometriosis also had fewer retrieved oocytes (MD −1.61, 95% CI −2.44 to −0.78; I²=77.7%). Differences were not statistically conclusive for live birth per treatment attempt or transfer (RR 0.86, 95% CI 0.68–1.08), clinical pregnancy (RR 0.91, 95% CI 0.81–1.03), pregnancy loss (RR 0.96, 95% CI 0.47–1.94), mature oocytes (MD −0.92, 95% CI −1.88 to 0.04), or fertilized oocytes (MD −0.28, 95% CI −0.60 to 0.05).

Conclusions: The cumulative reproductive success and the yield of oocytes were reduced in endometriosis, but there was no definitive effect on individual-attempt outcomes. Caution should be used when interpreting the results due to heterogeneity and the small number of studies.