Definition & Overview

Intrauterine Insemination (IUI) is one of the most common forms of artificial insemination technique used to treat infertility. The procedure involves placing sperm inside the uterus, fallopian tubes, or cervix during a time when the ovary releases eggs to increase the chances of fertilization. IUI is less invasive and a more affordable option when compared to in vitro fertilization with a success rate of about 5% for couples with unexplained infertility and about 16% when fertility drugs such as Clomid are used. So far, there is are no available statistics for live birth.

Who should undergo and expected results

Prior to choosing any type of assisted reproductive technique (ART), couples typically go through a series of tests to determine the cause/s of infertility. IUI is recommended if the reason that the couple is unable to conceive is one or a combination of the following:

  • Unexplained infertility. This refers to cases where standard infertility testing was unable to determine the exact causes why the couple is unable to conceive. Based on research up to 26% of infertile couples have unexplained infertility.
  • Abnormally thick cervical mucus. The cervix, which is located at the lower end of the vagina, produces mucus during a time when a woman ovulates. The mucus helps the sperm travel smoothly from the vagina to the fallopian tubes. However, there are cases when the body produces abnormally thick cervical mucus, preventing the sperm from reaching its destination.
  • Sperm abnormalities. Abnormalities in sperm morphology are some of the most common reasons why some couples are unable to conceive. Common cases are weak motility, lower than average sperm count, and abnormalities in sperm size.
  • This is a medical condition characterized by displaced endometrial tissue. Instead of lining the inside of the uterus, it grows outside.
  • The presence of cervical scar tissue from past procedures
  • Ejaculation dysfunction

Meanwhile, intrauterine insemination is not recommended for women who have severe diseases that affect the fallopian tubes and with a history of pelvic infections.

How the procedure works

Prior to the actual procedure, the male partner provides a semen sample, which will be washed to remove non-sperm elements, thereby reducing the possibility of the body reacting to it negatively. In the process, low-quality sperm cells are removed to obtain a highly concentrated sample of healthy sperm cells.

Depending on the cause of infertility problem, the woman may be placed on fertility drugs a week before she is expected to ovulate. She is then instructed to monitor for signs of impending ovulation. This procedure can be performed in a hospital using a transvaginal ultrasound or by using at-home urine ovulation predictor kits that detect the presence of the luteinizing hormone in the urine. IUI is typically performed a day or two after the expected ovulation.

IUI takes only minutes to complete, and it is very similar to a Pap smear. After the sperm has been processed in the laboratory, a small sample is drawn into a sterile catheter, which is inserted through the cervix and into the uterus. The sperm will then be injected into the uterine cavity.

Success rates

Based on statistics and various studies, the success or failure of the procedure largely depends on the woman's age and underlying causes of infertility. For example, in cases that involve 30-year-old women who have polycystic ovarian syndrome, the success rate is about 20% and this depends on whether or not fertility pills were used. The number falls significantly for older women. In fact, 43-year-old women with unexplained infertility only have 1% chance of having a successful IUI.

Possible risks and complications

Just like other assisted reproductive technology (ART), Intrauterine Insemination is generally safe and involves just a small amount of discomfort during the actual process. Although there are some risks and complications, serious cases are very rare. Risks include:

  • Infection – Based on research, there is a 1% chance that the woman could develop an infection in the fallopian tubes and uterus if the semen were contaminated or if the catheter that was used in the procedure was not properly sterilized.
  • Minor bleeding – There are cases wherein the process of placing a catheter in the uterus have resulted in spotting or minor bleeding. However, this is not serious and is expected to resolve on its own after one to two days. This also does not affect the patient's chances of conceiving.
  • Multiple pregnancy – IUI, when performed in combination with ovulation-inducing medications, can result in multiple pregnancy, which has higher risks including low birth weight and early labor.
  • Effectiveness. Perhaps, the biggest concern for people who are undergoing IUI is whether or not it will deliver the expected results. With just 1-25% chances of conceiving, it may take three to four attempts before a woman conceives. However, there are cases wherein the procedure fails altogether, leaving patients disheartened.


  • Reproductive health: Infertility FAQs. Centers for Disease Control and Prevention. Accessed May 21, 2013.

  • Infertility fact sheet. Accessed May 21, 2013.
  • Ginsberg ES. Procedure for intrauterine insemination (IUI) using processed sperm. Accessed May 21, 2013.
  • Tournaye HJ, et al. Management of male-factor infertility. Best Practice and Research: Clinical Obstetrics and Gynaecology. 2012;26:769.
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