Laparoscopic excision of endometriotic cysts is the main stream surgical intervention for treatment of endometriosis. However there is evidence that intervention may effect ovarian reserve by destruction of healthy ovarian tissue during surgery. Available evidence on the topic are contradictory and employed research methodology are diverse. There is need for an adequately powered research with proper methodology to assess actual effects of surgery.

Inclusion Criteria:

• Women with endometrioma cyst(s)
• Women of age under 35 years old
• Women without any previous ovarian surgery

Exclusion Criteria:

• Combined oral contraceptive or long term GnRH (gonadotropin-releasing hormone) analog use in the preceding 3 months to enrolment
• Having another cystic lesion besides endometrioma
• Need for extensive bipolar coagulation during surgery
• Any anatomical problem preventing evaluation of ovaries with high-resolution ultrasound
• Postoperative pathology excluding endometrioma

This study will recruit healthy women besides having endometrioma cysts who will undergo laparoscopic removal of such lesions.