Endometriosis fertility index: the new, validated endometriosis staging system.

OBJECTIVE To develop a clinical tool that predicts pregnancy rates (PRs) in patients with surgically documented endometriosis who attempt non-IVF conception. DESIGN Prospective data collection on 579 patients and comprehensive statistical analysis to derive a new staging system--the endometriosis fertility index (EFI)--from data rather than a priori assumptions, followed by testing the EFI prospectively on 222 additional patients for correlation of predicted and actual outcomes. SETTING Private reproductive endocrinology practice. PATIENT(S) A total of 801 consecutively diagnosed and treated infertile patients with endometriosis. INTERVENTION(S) Surgical diagnosis and treatment followed by non-IVF fertility management. MAIN OUTCOME MEASURE(S) The EFI and life table PRs. RESULT(S) A statistically significant variable used to create the EFI was the least function score (i.e., the sum of those scores determined intraoperatively after surgical intervention that describe the function of the tube, fimbria, and ovary on both sides). Sensitivity analysis showed that the EFI varies little, even with variation in the assignment of functional scores, and predicted PRs. CONCLUSION(S) The EFI is a simple, robust, and validated clinical tool that predicts PRs after endometriosis surgical staging. Its use provides reassurance to those patients with good prognoses and avoids wasted time and treatment for those with poor prognoses.