The aim of this study is to compare the rate of miscarriage at first spontaneous pregnancy among women with endometriosis with the rate of miscarriage at first spontaneous pregnancy among women without endometriosis.

All women followed up for a surgical or sonographic diagnosis of endometriosis in 11 italian referral Centres for the treatment of endometriosis completed a questionnaire regarding their previous pregnancies. The same questionnaire was completed by women, attending a routine gynecologic visit, in whom surgery or vaginal examination and pelvic ultrasonography excluded endometriosis.

Inclusion Criteria:

• 30 to 50 years old women
• with at least one previous spontaneous pregnancy
• with surgical or clinical/sonographic diagnosis of endometriosis or
• in whom surgical or clinical/sonographic evaluation ruled out endometriosis

Exclusion Criteria:

• Pregnancy achieved by Assisted Reproductive technology
• Biochemical pregnancy
• Non corrected uterine malformation, poliabortivity, lupus like anticoagulant

All continous women attending endometriosis clinics or undergoing a routine gynecological examination matching the inclusion criteria