What is intrauterine insemination (IUI)?

Paul Claman, a reproductive medicine specialist, explains everything you need to know about intrauterine insemination.

intrauterine insemination iui graphic Photo: Nica Patricio

What is it? Intrauterine insemination (IUI) is a type of artificial insemination used to treat infertility. During this procedure, sperm that has been specially prepared is placed in your uterus around the time of ovulation. Depending on your situation, IUI will be timed in accordance with your cycle or fertility medications.

Who can benefit from IUI? If the man has poor sperm quality, the couple may benefit from IUI. If he has severe problems with sperm quality, though, the couple may be better suited to in vitro fertilization (IVF), says Paul Claman, a reproductive-medicine specialist and founding partner of the Ottawa Fertility Centre. It’s a reasonable option for couples who are unable to have sex due to disability, injury or premature male ejaculation. Women with unexplained, endometriosis-related or cervical factor infertility (where the cervical mucus is too thick and interferes with sperm transport) may also opt for IUI. This is also a popular option for single women or same-sex female couples using donor sperm.

Claman cautions that IUI is not an effective treatment if the woman has blocked Fallopian tubes or is in her late 30s to early 40s. In these cases, IVF treatments may be the better option.

What does the procedure involve? IUI does not generally seem to improve the chances of pregnancy unless combined with fertility drugs. In unstimulated cycles—most often used in cases of sexual dysfunction or with normal donor sperm—IUI is simply timed to ovulation based on a home ovulation detection kit, which detects the luteinizing hormone (LH) surge in your urine. Your doctor may need to use daily LH blood tests to identify the best timing for the IUI procedure. In women who have regular periods and are undergoing unstimulated IUI treatment, IUI is done the day after detecting an LH surge in the urine or blood, which is tested 13 to 15 days before the next expected menstrual flow.

For patients with unexplained infertility or problems with sperm quality, IUI is typically done together with fertility drugs to stimulate egg production. Fertility drugs are used to encourage the ovary to mature and release more than one egg at the time of ovulation—this is referred to as superovulation. If you’re taking fertility drugs, you will be monitored by an ultrasound every few days and undergo frequent blood testing, says Claman. Superovulation with IUI (SO-IUI) is often done using pills (such as clomiphene citrate) or, more effectively, daily self-injected medications (such as follicle-stimulating hormone). Once the ultrasound examination shows that the egg follicles are mature, you may also be given an injection of human chorionic gonadotropin (hCG), which acts as a surrogate for the LH surge (with superovulation, it’s possible that you may not mount your own pre-ovulatory LH surge, which is critical for egg maturation and release).

Some of the common side effects of this injection include inflammation at the injection site and abdominal bloating from egg follicle development. Oral fertility stimulants are more often associated with mood swings, headaches and fatigue.


Before the actual procedure, a semen sample is prepared in the laboratory to select the healthiest sperm for insemination. Sperm preparation helps separate healthier sperm from abnormal sperm and improve the sperm’s ability to swim in a progressive direction. The sperm preparation also separates actual sperm from prostate gland fluid found in the ejaculate, which would cause severe uterine cramping if inserted into the uterus.

Using a thin tube or catheter, a doctor or trained nurse inserts the semen into the uterus—this is timed with your ovulation so that a greater number of sperm can reach the mature eggs. The visit to the doctor generally takes no longer than 30 minutes (the procedure itself only takes a few minutes and is generally painless). After insemination, the patient is asked to lie quietly for about 10 minutes before leaving the clinic to be able to carry on with the rest of the day without restrictions.

What are the risks? One of the biggest risks with IUI done with fertility drugs is getting pregnant with multiples.

With SO-IUI using oral fertility drugs, about 10 percent of pregnancies are at least twins. With injectable fertility drugs, about 20 percent of pregnancies are multiple births. There are a fair number of complications associated with carrying multiples. Twenty-five percent of babies born from a twin pregnancy spend more than one week in a newborn intensive care unit after birth due to pregnancy complications—most commonly, premature birth. As a result, babies born from a multiple pregnancy are at a much higher risk of serious long-term developmental problems than children of singleton births.


Other risks of SO-IUI include ovarian torsion, an uncommon complication where the enlarged ovary filled with egg follicles twists on itself and cuts off its own blood supply, and ovarian cysts that can persist for some months after treatment. Ovarian torsion needs to be treated with emergency surgery to untwist the ovary; in some cases, the affected ovary needs to be removed. Some women also experience non-threatening, light spotting one or two days after insemination.

How successful is it? The success rate of SO-IUI depends on the age of the woman, the cause of infertility and the quality of the sperm. According to the Ottawa Fertility Centre’s website (, a healthy woman under 35 can expect a success rate of about 19 percent per procedure. Though it’s common for women to try SO-IUI more than once, if a pregnancy doesn’t occur after four treatment cycles, the likelihood of success is slim.

This article was originally published on May 10, 2016

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