Prevention of follicular maturation in endometriosis by subcutaneous infusion of luteinizing hormone-releasing hormone agonist started in the luteal phase*

Six endometriosis patients were treated with continuous subcutaneous (SC) infusion of a luteinizing hormone-releasing hormone (LH-RH) agonist using an external osmotic minipump system. Serum estradiol (E 2 ) was suppressed into the menopausal range within 1 to 2 weeks of treatment started between days 9 and 12 after ovulation. The down-regulation of the pituitary-ovarian axis was maintained for the 24 weeks of treatment. Endometriosis symptoms were relieved during the treatment. At control laparoscopy, implants had regressed markedly and some adhesions had softened, accounting for a significant 58.3% reduction in the mean total American Fertility Society score. Ovulation returned within 14 to 38 days. Four infertile women became pregnant within 2 to 5 months after cessation of treatment. Frequent side effects were hot flushes, and decreased vaginal secretion and libido. There were no significant changes in laboratory blood tests, including cholesterol. The urinary calcium/creatinine ratio increased during the treatment. Thus, starting the treatment in the luteal phase prevented initial follicular stimulation. A better efficacy of treatment would be achieved by the release of an LH-RH agonist at a constant daily rate.