RESUMEN
Long-term pituitary down-regulation with a gonadotrophin-releasing hormone (GnRH) agonist for 36 months prior to IVF/intracytoplasmic sperm injection (ICSI) improves clinical pregnancy rates in endometriosis patients. However, some discussion about this treatment strategy still exists. This retrospective study from a tertiary-care university hospital examined the efficacy and safety of IVF/ICSI with and without long-term pituitary down-regulation in severe endometriosis patients (surgically confirmed American Society for Reproductive Medicine stages III and IV). All first IVF/ICSI treatment cycles between January 2009 and January 2012 were analysed. In patients treated with (n = 68) and without (n = 45) long-term pituitary down-regulation, 13 (19.1%) versus nine (20.0%) ongoing pregnancies after fresh embryo transfer (adjusted OR 0.58, 95% CI 0.181.86,) and 24 (35.3%) versus 10 (22.2%) ongoing pregnancies after fresh and cryopreserved embryo transfers (adjusted OR 1.62, 95% CI 0.604.38) were accomplished, respectively. Three complications (2.7%) and three recurrences (2.7%) were reported, only in patients treated with long-term pituitary down-regulation. The 1-year cumulative endometriosis recurrence rate was 7.3%. IVF/ICSI in patients with severe endometriosis is safe with low complication and recurrence rates. A favourable effect, albeit non-significant, of long-term pituitary down-regulation in achieving an ongoing pregnancy was observed only after including cryopreserved embryo transfers.