What is intrauterine insemination (IUI) and how does it work?

What is IUI?

Intrauterine insemination (IUI) involves a laboratory procedure to separate fast moving sperm from more sluggish or non-moving sperm.

The fast moving sperm are then placed into the woman’s womb close to the time of ovulation when the egg is released from the ovary in the middle of the monthly cycle. 


Is IUI for me?

Your clinic may recommend IUI if:

  • there is unexplained infertility
  • there are ovulation problems
  • the male partner experiences impotence or premature ejaculation
  • you do not have any known fertility problems but may not have a male partner and are trying for a baby using donated sperm.

Patency health tests
It is essential that your fallopian tubes are known to be open and healthy before the IUI process begins. A tubal patency test is usually carried out as part of your assessment by the fertility clinic. 

The typical method for assessing the health of your pelvis and the patency of your fallopian tubes is laparoscopy and dye testing.

At laparoscopy a direct view of the pelvis is obtained by inserting a telescope into the abdomen.

When the pelvis and tubes are healthy, dye passes freely through both tubes. There should be no adhesions present that might prevent an egg from having access to either tube from the ovaries. This is performed under a short general anaesthetic.

The test may show that you only have one open healthy tube although you may have both ovaries. IUI treatment can then only be carried out when there is evidence that ovulation is about to occur from the ovary that is on the same side as the open tube.

The second essential requirement is that there is no significant problem with sperm numbers or sperm quality.

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IUI options

If your clinic has recommended IUI treatment, you may want to have a discussion with your clinician about the risks involved in using fertility drugs to boost egg production and whether IUI without fertility drugs might be suitable for you.

If IUI is unsuccessful you may want to talk to your clinician about other procedures such as IVF.

How does IUI work?

Patency health tests 

IUI can only begin once it has been confirmed that your fallopian tubes are open and healthy. This will usually be checked through a tubal patency test as part of your assessment by the fertility clinic.

This may involve a laparoscopy, an operation in which a dye is injected through your cervix as the pelvis is inspected for blockages with a telescope that has a tiny camera attached (a laparoscope).

Alternatively, you may undergo a hysterosalpingo-contrast sonography (HyCoSy) – which involves using a vaginal ultrasound probe to check the fallopian tubes for blockages – or a hysterosalpingogram, an x-ray of your fallopian tubes.

The procedure

For women

If you are not using fertility drugs, IUI will be performed between day 12 and 16 of your monthly cycle – with day one being the first day of your period. You will be given blood tests or urine tests to identify when you are about to ovulate.


If you use fertility drugs to stimulate ovulation, vaginal ultrasound scans are used to track the development of your eggs. As soon as an egg is mature, you are given a hormone injection to stimulate its release.

The sperm will be inserted 36–40 hours later. The doctor will first insert a speculum into your vagina, as in a smear test, to keep your vaginal walls apart. A small catheter (a soft, flexible tube) will then be threaded into your womb via your cervix. The best-quality sperm will be selected and inserted through the catheter.

The whole process only takes a few minutes and is usually painless. Some women may experience a temporary, menstrual-like cramping. You may want to rest for a short time before going home.

For men:

You will be asked to produce a sperm sample on the day the treatment takes place.

The sperm will be washed to remove the fluid surrounding them and the rapidly moving sperm will be separated out from the slower sperm.

The rapidly moving sperm will be placed in a small catheter to be inserted into the womb.

If you are using donated or frozen sperm, it will be removed from frozen storage, thawed and prepared in the same way.

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...more about intrauterine insemination (IUI)

Page last updated: 09 December 2014

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