Background: Endometriosis is a main cause of female infertility. Surgical treatment of ovarian endometriomas raised great concerns about future fertility and the possible decline in ovarian reserve.  
Objective: Evaluate factors associated with the decline in ovarian reserve after surgical excision of the endometriomas. Study design: This cross-sectional study was conducted in tertiary hospital from 1/11/2020 to 31/7/2022. We recruited eligible patients during the study duration according to predetermined inclusion and exclusion criteria. Eligible patients were subjected to ultrasound examination to diagnose ovarian endometrioma, its diameter, and the AFC of the affected. The AMH was also withdrawn. Patients were prepared for laparoscopic cystectomy. After three months, patients were subjected to reevaluation, including recurrence of the cyst, AFC, AMH levels, and patient satisfaction using the endometriosis treatment satisfaction questionnaire.
Results: Sixty patients were recruited throughout the study duration. The mean age was 30.33 ± 7.95. The recurrence rate was 19/60 (31.7%). There was a significant reduction in the cyst diameter, AFC, and AMH after surgical excision (p-value <0.001). Only preoperative AFC and AMH levels were significant predictors for each marker individually (p<0.001). There was a significant increase in all domains of the endometriosis treatment satisfaction questionnaire and the total score (p-value <0.001).
Conclusion: Surgical removal of endometriomas was associated with a significant decline in ovarian reserve. The decline in AFC and AMH was independent of other patient-related factors but for preoperative AMH, which affected post-operative AMH levels significantly.