The administration of GnRH agonists for a period of three to six months prior to IVF or ICSI in women with endometriosis increases the odds of clinical pregnancy by fourfold. Data regarding adverse effects of this therapy on the mother or fetus are not available at present.
Effect of prolonged gonadotropin-releasing hormone agonist therapy on the outcome of in vitro fertilization-embryo transfer in patients with endometriosis.
To evaluate the effect of a 3-month course of GnRH agonist administered immediately before IVF-ET in infertile patients with endometriosis.
                Prospective, randomized trial.
                Three tertiary care assisted reproductive technology programs.
                IVF-ET candidates with surgically confirmed endometriosis.
                Twenty-five patients received three courses of a long-acting GnRH agonist, 3.75 mg i.m. every 28 days, followed by standard controlled ovarian hyperstimulation. Twenty-six patients received standard controlled ovarian hyperstimulation with mid-luteal phase GnRH agonist down-regulation or microdose flare regimens.
                Response to controlled ovarian hyperstimulation, ongoing pregnancy rates per cycle, group implantation rates, and implantation rate per embryo transfer procedure.
                The extent of surgically confirmed endometriosis was greater in patients who received the long-acting GnRH regimen for 3 months before IVF-ET. The groups did not differ significantly in terms of dose or duration of gonadotropin stimulation, number of oocytes retrieved, fertilization rate, or number of embryos transferred. Patients who received the long-acting GnRH regimen had significantly higher ongoing pregnancy rates (80% vs. 53.85%) and a trend toward higher implantation rates (42.68% vs. 30.38%).
                Prolonged use of GnRH agonist before IVF-ET in patients with endometriosis resulted in significantly higher ongoing pregnancy rates than did standard controlled ovarian hyperstimulation regimens. No deleterious effect on ovarian response was observed.