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 two IUI treatment strategies performed between January 2007 and July 2012 in moderate-to-severe endometriosis patients. Eight (40.0%) versus seven (15.6%) ongoing pregnancies were accomplished in patients undergoing IUI with ovarian stimulation (n=20, 61 cycles) versus IUI without ovarian stimulation in the first three cycles followed by IUI with ovarian stimulation (IUI with natural/ovarian stimulation; n=45, 184 cycles). Preceding long-term pituitary down-regulation tended to result in a higher ongoing pregnancy rate (adjusted HR 1.8) and a higher chance of endometriosis recurrence (adjusted HR 2.3). Eight (40.0%) versus 16 (35.6%) recurrences of endometriosis complaints were reported in patients receiving IUI with ovarian stimulation versus IUI with natural/ovarian stimulation. IUI might be a valuable treatment in moderate-to-severe endometriosis patients and IUI with ovarian stimulation should be offered over IUI with natural/ovarian stimulation. Preceding long-term pituitary down-regulation 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.