Does the levonorgestrel-releasing intrauterine device (LNG-IUD) influence cumulative live birth rate (CLBR) in oocyte donor cycles?Retrospective cohort study based on prospectively collected data from 1 May 2009 to 31 December 2017, without attrition, consisting of 491 consecutive cycles of vitrified oocyte donation, none lost to follow-up (unique donor-recipient pairs). All donors underwent ovarian stimulation using gonadotrophin releasing hormone (GnRH) antagonist co-treatment and GnRH agonist trigger. CLBR was chosen as primary outcome measure.In total, 103 (21.0%) cycles were carried out in donors carrying a LNG-IUD. In 388 (79.0%) cycles, no LNG-IUD was present. After confounder-adjustment, the use of an LNG-IUD did not have a statistically significant influence on CLBR.The LNG-IUD does not negatively affect CLBR.