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 fertilised. 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.

Why Is It Done?

Intrauterine insemination is used most often in couples who have:

  • 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 (sub-fertility). 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 mobile, 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.

How Do You Prepare?

Intrauterine insemination involves careful coordination before the actual procedure:

  • Preparing the semen sample: Your partner provides a semen sample at the doctor’s office, or a vial of frozen donor sperm can be thawed and prepared. Because nonsperm elements in semen can cause reactions in the woman’s body that interfere with fertilization, the sample will be washed in a way that separates the highly active, normal sperm from lower quality sperm and other elements. The likelihood of achieving pregnancy increases by using a small, highly concentrated sample of healthy sperm.
  • Monitoring for ovulation: Because the timing of IUI is crucial, monitoring for signs of impending ovulation is critical. To do this, you might use an at-home urine ovulation predictor kit that detects when your body produces a surge or release of luteinizing hormone (LH). Or, an imaging method that lets your doctor visualize your ovaries and egg growth (transvaginal ultrasound) can be done. You also may be given an injection of human chorionic gonadotropin (HCG) to make you ovulate one or more eggs at the right time.
  • Determining optimal timing: Most IUIs are done a day or two after detecting ovulation. Your doctor should have a plan spelled out for the timing of your IUI.