Van Eekelen R, et al. - Researchers investigated the efficacy of starting IUI with ovarian stimulation (IUI-OS) within 1.5 years after completion of the fertility workup in increasing ongoing pregnancy rates vs expectant management in couples with unexplained subfertility. They performed a prospective cohort study on couples with unexplained or mild male subfertility who could start IUI-OS at any point after completion of the fertility workup, recruited between January 2002 and February 2004 in seven Dutch centers. Compared to expectant management, higher chances of ongoing pregnancy in unexplained subfertile couples were associated with IUI-OS, noted particularly for those with poor prognoses of natural conception, ie, <15% over 6 months or <25% over 1 year.