One-year follow-up of serum antimüllerian hormone levels in patients with cystectomy: are different sequential changes due to different mechanisms causing damage to the ovarian reserve?

OBJECTIVE: To investigate whether the serum antimüllerian hormone (AMH) levels recover within 1 year after cystectomy for endometriomas, and to analyze the pattern of sequential changes in the serum AMH levels.
DESIGN: Prospective study.
SETTING: University hospital. PATIENT(S): Thirty-nine patients undergoing cystectomy for unilateral endometrioma (n = 22) and bilateral endometriomas (n = 17). INTERVENTION(S): Serum samples collected 2 weeks before, and 1 month and 1 year after surgery were assayed for AMH levels. MAIN OUTCOME MEASURE(S): Assessment of the ovarian reserve damage based on alterations in the serum AMH levels and the association with parameters of endometriosis and surgery for endometriomas. RESULT(S): The median AMH levels were 3.56, 1.90, and 2.10 ng/mL before, 1 month after, and 1 year after surgery, respectively. Twenty patients showed higher AMH levels 1 year after surgery than 1 month after surgery (increase group); 19 patients showed lower AMH levels (decrease group). We found a statistically significant difference in the number of follicles removed by surgery between the two groups. CONCLUSION(S): The decrease in the serum AMH levels caused by cystectomy can recover. Our results suggest that removal of ovarian cortex might be involved in the decrease of the ovarian reserve just after surgery, and that a continuous decrease of the ovarian reserve after cystectomy might be attributed to other mechanisms.