Intrauterine insemination (IUI) — a type of artificial insemination — is a procedure for treating infertility.
Sperm that have been washed and concentrated are placed directly in your uterus around the time your ovary releases one or more eggs to be fertilized. Older types of artificial insemination placed the sperm in the vagina. While this was easier, it was not as successful as the current procedure.
The hoped-for outcome of intrauterine insemination is for the sperm to swim into the fallopian tube and fertilize a waiting egg, resulting in a normal pregnancy. Depending on the reasons for infertility, IUI can be coordinated with your normal cycle or with fertility medications.
A couple’s ability to become pregnant depends on many different factors. Intrauterine insemination is used most often in couples who have:
- Donor sperm. For women who need to use donor sperm to get pregnant, IUI is most commonly used to achieve pregnancy. Frozen donor sperm specimens are obtained from certified labs and thawed before the IUI procedure.
- Unexplained infertility. IUI is often performed as a first treatment for unexplained infertility along with ovulation-inducing medications.
- Endometriosis-related infertility. For infertility related to endometriosis, using medications to obtain a good quality egg along with performing IUI is often the first treatment approach.
- Mild male factor infertility (subfertility). Your partner’s semen analysis, one of the first steps in the medical assessment of infertility, may show below-average sperm concentration, weak movement (motility) of sperm, or abnormalities in sperm size and shape (morphology). IUI can overcome some of these problems because preparing sperm for the procedure helps separate highly motile, normal sperm from those of lower quality.
- Cervical factor infertility. Your cervix, at the lower end of the uterus, provides the opening between your vagina and uterus. Mucus produced by the cervix around the time of ovulation provides an ideal environment for sperm to travel from your vagina to the fallopian tubes. But, if your cervical mucus is too thick, it may impede the sperm’s journey. IUI bypasses the cervix, depositing sperm directly into your uterus and increasing the number of sperm available to meet the awaiting egg.
- Semen allergy. Rarely, a woman could have an allergy to proteins in her partner’s semen. Ejaculation into the vagina causes redness, burning and swelling where the semen contacts the skin. A condom can protect you from the symptoms, but it also prevents pregnancy. If your sensitivity is severe, IUI can be effective, since many of the semen proteins are removed before the sperm is inserted.
Intrauterine insemination is a relatively simple and safe procedure, and the risk of serious complications is low. Risks include:
- Infection. There’s a slight risk of developing an infection as a result of the procedure.
- Spotting. Sometimes the process of placing the catheter in the uterus causes a small amount of vaginal bleeding. This doesn’t usually have an effect on the chance of pregnancy.
- Multiple pregnancy. IUI itself isn’t associated with an increased risk of a multiple pregnancy — twins, triplets or more. But, when coordinated with ovulation-inducing medications, the risk of a multiple pregnancy increases significantly. A multiple pregnancy has higher risks than a single pregnancy does, including early labor and low birth weight.
Several factors place you at greater risk of developing endometriosis, such as: Never giving birth
- Never giving birth
- Starting your period at an early age
- Going through menopause at an older age
- Short menstrual cycles — for instance, less than 27 days
- Having higher levels of estrogen in your body or a greater lifetime exposure to estrogen your body produces
- Low body mass index
- Alcohol consumption
- One or more relatives (mother, aunt or sister) with endometriosis
- Any medical condition that prevents the normal passage of menstrual flow out of the body
- Uterine abnormalities
Endometriosis usually develops several years after the onset of menstruation (menarche). Signs and symptoms of endometriosis end temporarily with pregnancy and end permanently with menopause, unless you’re taking estrogen.