The management of endometriosis-related infertility remains controversial. In particular, there is an equipoise for infertile women with endometriotic lesions detected at ultrasound. These women can be managed with either surgery or in vitro fertilization (IVF). The two approaches radically differ and they have never been compared with a randomized trial. As a consequence, affected women currently receive contrasting information and the mode of treatment substantially differ among centres, reflecting the local expertise of physicians rather than clinical needs.

The present study aims at clarify whether IVF could be superior to surgery in infertile women with endometriotic lesions detected at ultrasound. This topic will be addressed comparing the two approaches in terms of effectiveness and cost-effectiveness. In addition, the study will disentangling whether the endometriosis-related systemic inflammatory mechanisms may have an impact on the quality of folliculogenesis and on IVF outcomes. This specific objective will be pursued through the characterization and analysis of circulating extracellular vesicles (EV)-immunologic, proteomic and miRNA signatures and measurement of steroid hormones in follicular fluid.

Women accepting to enter the study will be randomized to either surgery and then natural pregnancy seeking or a program of three complete IVF cycles (i.e. three oocytes retrievals regardless of the number of embryo transfers performed). The initial time point will be the time of randomization. Women of both study groups will initiate treatment (surgery or IVF) in a shortest delay, maximum 3 months. Only live birth pregnancies and initiating within a 12-months period starting from this time point will be included in the primary outcome.

Inclusion Criteria:

• Age < 40 years
• Pregnancy seeking for more than 12 months
• Regular menstrual cycle, i.e. mean cycle interval between 21 and 35 days
• Ultrasonographic diagnosis of ovarian endometriomas or deep peritoneal endometriosis.
• Normal seminal analysis based on WHO criteria
• Absence of ureteral stenosis or intestinal subocclusive symptoms

Exclusion Criteria:

• Previous surgery for endometriosis
• Previous IVF cycles
• Contraindication to pregnancy
• Hydrosalpinx
• Endometriomas with a mean diameter > 4 cm
• Submucosal fibroids or large intramural or subserosal fibroids (≥ 5 cm).
• Doubtful sonographic findings that do not allow to reliably rule out malignancy.
• Obstacles to regular sexual intercourses (sexual disturbances or logistic problems)