A randomized, double-blind, placebo-controlled study of luteal phase dydrogesterone (Duphaston) in women with minimal to mild endometriosis.

OBJECTIVE: To compare dydrogesterone with placebos in the treatment of minimal to mild endometriosis.

DESIGN: Prospective, double-blind, randomized study.

SETTING: Three Obstetrics and Gynaecology Departments in the United Kingdom.

PATIENTS: Sixty-two premenopausal women with complaints of pain (n = 12) and infertility with or without pain (n = 50) with minimal to mild endometriosis diagnosed at laparoscopy. Thirty-nine women had a laparoscopy after treatment and 56 women were followed up 12 months after treatment.

INTERVENTIONS: Two high doses of dydrogesterone (either 40 or 60 mg) or a placebo, which was given for 12 days, beginning 2 days after the LH surge for a treatment period of 6 months.

MAIN OUTCOME MEASURES: Change between before and after treatment endometriosis scores, pregnancy rates (PRs), and pain.

RESULTS: Treatment with dydrogesterone did not alter the natural history of endometriosis or PRs when compared with placebo. Pain was reduced significantly during treatment with 60 mg dydrogesterone and this improvement still was evident at 12-month follow-up.

CONCLUSION: Luteal phase dydrogesterone reduces pain associated with endometriosis.