Efficacy and safety of intrauterine insemination in patients with moderate-to-severe endometriosis

Performing intrauterine insemination (IUI) in moderate-to-severe endometriosis patients is not implemented in international guidelines, as only limited data exist on treatment efficacy and safety. This retrospective study examined the efficacy and safety of IUI performed between January 2007 and July 2012 in moderate-to-severe endometriosis patients (ASRM III-IV). Two treatment strategies were compared: IUI with ovarian stimulation (20 patients, 61 cycles and IUI without ovarian stimulation in the first three cycles followed by IUI with ovarian stimulation (45 patients, 184 cycles, IUI with natural/ovarian stimulation). Also, the additional effect of preceding long-term pituitary down-regulation was investigated. Eight (40.0%) and seven (15.6%) ongoing pregnancies were accomplished in patients undergoing IUI with ovarian stimulation and IUI with natural/ovarian stimulation (P = 0.05). Preceding long-term pituitary down-regulation with a gonadotrophin-releasing hormone (GnRH) agonist tended to result in a higher ongoing pregnancy rate (adjusted HR 1.8). Eight (40.0%) and 16 (35.6%) recurrences of endometriosis complaints were reported in patients undergoing IUI with ovarian stimulation and IUI with natural/ovarian stimulation. Preceding long-term pituitary down-regulation with a GnRH agonist tended to result in a higher chance of endometriosis recurrence (adjusted HR 2.3). Although IUI is not implemented in the current guidelines, IUI with ovarian stimulation could be a valuable treatment in moderate-to-severe endometriosis patients. Long-term pituitary down-regulation with a GnRH agonist prior to the first IUI treatment cycle might positively influence the ongoing pregnancy rate and can be considered. Whether this treatment strategy can be structurally offered prior to IVF must be investigated in a randomized controlled trial.