Abstract: Objective：To assess the value of endometriosis fertility index (EFI) in predicting the choice of pregnancy in those infertile patients with endometriosis after laparoscopic surgery. Methods: Clinical data of 148 infertile patients with endometriosis underwent laparoscopic surgery were retrospectively studied from Jan. 2013 to Dec. 2014. The pregnancy outcome was followed up by telephone. The EFI score was calculated. Accordingly, patients were grouped, and the pregnancy rate was compared. The receiver operating characteristic (ROC) curve was used to evaluate the value of EFI in predicting the nature pregnancy. Results: The negative correlation between the rate of natural pregnancy and the EMs stage was found in 36 months after operation（rs=-0.535，P＜0.001）. The rate of natural pregnancy in EMs patients in 6 months after operation was significantly higher than those in 7-12, 13-24 and 25-36 months after operation. There was a positive correlation between the rate of natural pregnancy and the EFI score in EMs patients in 36 months after operation（rs=0.617，P＜0.001）. The rates of pregnancy in those patients with the EFI scores of 9-10, 7-8 and 5-6 were significantly higher in 6 months after operation. The area under curve (AUC) of the ROC curve of EFI was 0.854（95%CI：0.794-0.915，P＜0.001）. The critical value of the EFI score predicted by AUC was 6.5 in one year of operation, with the sensitivity of 73.42% and the specificity of 82.61%. Conclusions: EFI score was positively correlated with the rate of natural pregnancy in those EMs patients after laparoscopic surgery, suggesting that EFI score can be tried to predict the natural pregnancy in one year after operation. One year after surgery is the best duration for the patient to have a pregnancy.

Key words: Endometriosis fertility index;, Endometriosis, Infertility, female, Laparoscopes, Laparoscopy, Pregnancy rate