Abstract
<jats:title>Abstract</jats:title> <jats:p>Intra-uterine insemination (IUI) involves the timed introduction of selected sperm into the uterine cavity around the time of ovulation in stimulated or unstimulated cycles. The usual indications are mild male factor infertility or idiopathic (unexplained) infertility. Following the laboratory preparation of a fresh semen sample by one of a number of available methods, the "improved" sample is introduced into the uterine cavity, so avoiding the cervical barrier and ensuring the placement of concentrated motile sperm closer to the available eggs. One correctly timed IUI per cycle has proved equally as successful as two. If there are 1-5 million motile sperm available following preparation for male factor infertility, IUI is appropriate treatment. IUI is now widely used for the empirical treatment of idiopathic (unexplained) infertility. The combination of IUI in gonadotrophin stimulated cycles yields much improved results compared with unstimulated or clomiphene stimulated cycles. However, the multiple pregnancy rate is often high if undue care is not taken with the use of gonadotrophins. The cost effectiveness of IUI and gonadotrophins versus IVF for unexplained infertility is now under debate.</jats:p>