Long-term follow up of couples initially randomized between immobilization and immediate mobilization subsequent to IUI

A previous randomized clinical trial compared immobilization for 15 min with immediate mobilization subsequent to intrauterine insemination (IUI) and showed higher ongoing pregnancy rates in couples immobilizing subsequent to IUI. The current study compared the long-term effectiveness of immobilization subsequent to IUI. All couples (n = 391) included in the trial were followed for 3 years after randomization and pregnancies and treatments were recorded. After the initial trial period, couples in both groups were offered treatment according to local protocol. The primary outcome was an ongoing pregnancy during the 3 years after the initial trial. In this time period, there were 143 ongoing pregnancies in the immobilization group (n = 199 couples) and 112 ongoing pregnancies in the immediate mobilization group (n = 192). The ongoing pregnancy rates were 72% and 58%, respectively (relative risk 1.2, 95% CI 1.1–1.4). The persistent significant difference in ongoing pregnancy rates underpins the importance of immobilization after IUI. There is no valid reason to withhold women from immobilizing for 15 min after IUI.