ObjectiveTo investigate the effect of laparoscopic surgery combined with the following treatment of gonadotropin-releasing hormone agonist (GnRH-a) on the patients with endometriotic infertility and the value of endometriosis fertility index (EFI) system on forecasting the pregnancy outcome. MethodsFrom January 2005 to July 2011, the clinical data of 15 patients with endometriotic infertility patients were analyzed retrospectively. All the patients underwent laparoscopic surgery, and the effect was evaluated according to the endometriosis fertility index (EFI). Then all the patients were divided randomly into two groups on the basis of the different assisted treatment after the laparoscopic surgery:the control group (without any other therapy) and the GnRh-a group (combined with GnRH-a). Eventually, the pregnant rates were calculated respectively in the different groups or according to the different EFI. ResultsAt last, 103 cases finished the follow-up. The pregnancy rate in the control group after 6 months, 1 year and 3 years therapy were 12.5%, 31.2%, and 41.7%, respectively; while in the GnRh-a group were 0%, 16.3%, and 40.0%, respectively. There were no difference between the two groups after the 1 year and 3 years therapy (P>0.05). Besides, all of the 55 cases in the GnRh-a group had side-effects, but no severe adverse effect was encountered. All the side-effects were disappeared after stopping the treatment. The pregnancy rate of the patients with the EFI score of 8-10 was respectively 31.3% 1 year and 62.5% 3 years after the treatment. However, the pregnancy rate of the patients with the EFI score of 5-7 was respectively 15.2% 1 year and 26.0% 3 years after the treatment. There were only 9 patients with the EFI score of 0-4, and all of them were not pregnant. The EFI score had positive correlation with the pregnancy rate 1 year and 3 years after the treatment (rs=0.204, P=0.039; rs=0.437, P<0.001). ConclusionThe treatment of GnRh-a after the laparoscopic surgery can not only increase the rate of the pregnancy, but also delay the pregnancy occasion and increase the occurrence of the side-effects. The EFI may be valuable for forecasting the rate of pregnancy in patients with endometriotic infertility. The patients with EFI score higher than 8 may expect the pregnancy, while the ones with below 7 probably have much lower rate of natural pregnancy rate.