Quaas AM, Gavrizi SZ, Peck JD, et al. - Researchers undertook this multicenter randomized controlled trial to examine the link of endometrial thickness (EMT) with live birth rates (LBR) in ovarian stimulation with intrauterine insemination (OS-IUI) treatments for unexplained infertility. In this prospective cohort study of the Reproductive Medicine Network’s Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS), there were 868 couples with unexplained infertility (n = 2,459 cycles). Findings revealed higher LBR in association with increasing EMT in OS-IUI for unexplained infertility; however, no significant link of EMT with LBR was found when adjusted for OS treatment type. Results showed that appreciable LBR were observed at all EMT, even those of ≤ 5 mm, indicating that OS-IUI cycles should not be canceled for thin endometrium.