What is the most valid comparison treatment in trials of intrauterine insemination, timed or uninfluenced intercourse? A systematic review and meta-analysis of indirect evidence.

Timed intercourse (TI), which is the usual control treatment in trials of intrauterine insemination (IUI), is not a typical coital activity and could impair fertility. This review summarizes the trials of IUI of male partner's prepared semen among subfertile couples according to whether the control group had TI or expectant management.