Collaborative study of pregnancy rates following danazol therapy of stage I endometriosis.

Pregnancy rates following danazol therapy of endometriosis vary widely. In order to reduce variations in patient selection and establish danazol effectiveness, six collaborative centers evaluated 75 infertile patients with normal infertility screening studies and mild (stage I) endometriosis documented by laparoscopy. Following diagnosis and 3 months coital exposure, all patients were treated with danazol for 6 months, and patient surveillance after danazol therapy lasted at least 12 months, with a range of 12 to 34 months. Of the 75 patients treated, 21 (28%) conceived, and the term pregnancy rate was 20% (15 of 75). The low pregnancy rate observed in these patients suggests that the role of danazol therapy for patients with mild endometriosis and infertility should be reconsidered.