Project 8

Endometriomas are a type of endometriosis consisting of fluid filled benign cysts of the ovary. Endometriomas are associated with an increased risk of infertility and may require medical interventions to conceive. Management of these cysts prior to fertility treatment is controversial. On the one hand, leaving them has the potential for the cyst to get bigger and further damage ovarian tissue including eggs, as well as the very rare risks of malignancy and serious infection due to egg collection from the ovaries during fertility treatment. On the other hand, surgically removing the cyst has been shown to decrease the ovarian reserve, or the number of eggs left in the ovary and puts the patient through the risks of surgery.

This study aims to investigate how the ovarian reserve changes over time in patients with endometriomas left alone compared to those patients who have endometriomas surgically removed. This will help clinicians to decide the best way to manage these cysts in the future where fertility is desired. We plan to assess the ovarian reserve using a blood test to measure anti- mullerian hormone (AMH), which is secreted by the ovary and correlates with the number of available follicles (hosting future eggs). Participants in this study will already have a management plan for their endometrioma and we will observe the change in the ovarian reserve over time by taking blood samples at 7 time points: at recruitment, 6 months post-surgery or recruitment, 12 months post- surgery or recruitment and then again at 2, 3, 4 and 5 years. These time points will be similar for both groups (cyst removal or not) to ensure comparable times between recruitment and follow-up in both study arms. The results will be available to the participants and any abnormal results will be discussed with them by the investigative team and appropriate referrals made. The initial management plan will not be affected by this study.