From resolve.org, the National Infertility Association:
IUI is a procedure used for couples with unexplained infertility, minimal male factor infertility, and women with cervical mucus problems. IUI is often done in conjunction with ovulation-stimulating drugs. IUI can be performed using the husband’s sperm or donor sperm. Before IUI, the woman should be evaluated for any hormonal imbalance, infection or any structural problems.
Insemination is performed at the time of ovulation, usually within 24-36 hours after the LH surge is detected, or after the “trigger” injection of hCG is administered. Ovulation is predicted by a urine test kit or blood test and ultrasound.
In the case of husband inseminination, the male partner produces a specimen, at home or at the clinic or doctor’s office. The sperm is then prepared for IUI. Sperm from the male partner or third-party donor are “washed” or separated. Separation selects out motile sperm from the man’s ejaculate and concentrates them into a small volume. Sperm washing cleanses the sperm of potentially toxic chemicals which may cause adverse reactions in the uterus. The doctor uses a soft catheter that is passed through a speculum directly into the woman’s uterus to deposit the semen at the time of ovulation.
IUI may be used in conjunction with ovulatory medications, such as clomophine citrate, gonadotropins, or urofollitropins. If injectable ovulation stimulating drugs are used in an IUI cycle, careful monitoring is essential. Monitoring includes periodic blood tests and ultrasounds beginning around day 6 of the woman’s cycle. Results of these tests will indicate when eggs are mature, prompting the hCG shot.
IUI is also used with specially prepared donor sperm. The sperm bank sends the doctor’s office sperm that is already prepared for IUI.
IUI is a relatively quick procedure and is performed in the doctor’s office without any anesthesia. It should not be painful, although some women report mild discomfort.
We are doing a medicated cycle, started with Clomid on day 5-9 and an HCG trigger shot on day 13 or 14. They’ll be doing multiple ultrasounds to make sure I’m not super-ovulating, or producing more than 3-4 follicles(eggs), so that we don’t wind up with septuplets! The actual insemination should be 40 hours after that HCG trigger; according to the above information it should be quick and painless. And then two weeks later, we find out if it worked!