Intra-uterine insemination (IUI) is a treatment where sperm is prepared in a lab, then placed into the uterus at the time that eggs are released from the ovaries. This way, sperm doesn't have to fight its way to the uterus as it would do naturally. IUI is only suitable for women with patent (open) fallopian tubes and men with high sperm quality (or minor abnormalities). Many couples with unexplained infertility opt for IUI as a simpler option compared to IVF. It is often paired with ovulation-induction treatment, such as stimulation using clomiphene, to improve success rates. IUI treatment typically improves a couple's monthly chance of conception. The treatment cycle can be undertaken every month. Success rates will depend on a woman's age and the sperm quality, but in appropriately selected couples we expect half to have conceived by four cycles of treatment. Women are usually given clomiphene to encourage the growth of more than one follicle each cycle. The cycle is monitored in the days leading up to ovulation with blood tests to check hormone levels, and ultrasound scans to check the number of eggs growing in the ovaries. On the day of ovulation, sperm from the male partner is prepared in the laboratory. This process collects healthy sperm from the sample to use for insemination. This is placed into the uterus using a small catheter that is passed through the woman's cervix.