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Intrauterine insemination (IUI)

Although many couples are unable to have a child, infertility is a very personal issue. The suffering and despair which childlessness may bring to an otherwise perfect relationship is substantial.

Couples who are unable to conceive turn to their family doctor for advice and guidance - and sometimes to a specialist clinic for dedicated treatment.

A modern infertility clinic offers a range of treatments which may be difficult to comprehend. The choice of treatment will depend on the cause of the fertility problem which investigations reveal.



IUI is one of the simpler methods of assisted conception. The object of IUI  is to use fertility drugs to encourage egg development and then to introduce a quantity of sperm into the uterus at the time of ovulation. Usually it would only be considered at a treatment for couples whose initial investigations have failed to diagnose a specific cause for their fertility difficulties and who have been trying for a baby for at least 2 years.

Which couples benefit

Because the semen is transferred to the uterus, it is important that the female partner has no obvious reproductive abnormalities. Investigations should ideally show that the female is ovulating normally and has  patent fallopian tubes. This means that when the female partner releases an egg from the ovary at ovulation, the egg and the sperm are able to make contact without any obstructions.

As well as couples having unexplained infertility, IUI may still be effective in women with ovulatory disorders, provided they respond adequately to fertility drugs.

There has been some success with IUI in cases where the female partner is experiencing mild symptoms of a condition called endometriosis. This is a common disorder, particularly in women in their 30s who have no children, and it may account for as many as 1 in 15 cases of infertility. The condition is characterised by finding tissue from the lining of the womb (endometrium) elsewhere in the reproductive tract. It may cause symptoms of pelvic pain prior to the period and pain on intercourse.

Because IUI relies on the natural ability of sperm to fertilise an egg within the reproductive tract, it is important that sperm count and movement are normal. Similarly women with damaged tubes will not benefit from IUI.

How the technique works

The most recent studies suggest that the best results are achieved when insemination coincides with ovulation induced by fertility drugs. Therefore, following investigations, the first steps in IUI treatment are similar to those used in other assisted conception methods in that egg production is enhanced by fertility hormones and ovulation induced by different hormones when the eggs are mature.

The highest success rates have been achieved with fertility drugs known as gonadotrophins. Menopur® is the commonest gonadotrophin used to stimulated egg production, with Pregnyl® being used to induce ovulation.

Because fertility drugs can produce several eggs, monitoring is important during the drug treatment phase. This ensures that side effects of treatment and/or the risk of multiple pregnancy is minimised. Monitoring of treatment is carried out by observing follicle production on the ovaries using transvaginal ultrasound scanning and occasional hormone blood tests.

The aim of IUI is to produce 2 or 3 follicles. Each of these follicles would be expected to contain 1 egg. Production of more than 3 follicles would lead to stopping the treatment cycle, not performing the insemination and advice to the couple to use barrier contraception for the rest of the cycle so as to avoid any risk of conceiving a large multiple pregnancy.

When 2 or 3 follicles have reached their target size, ovulation is induced with Pregnyl®.  Ovulation occurs 38 to 40 hours after this hormone trigger, at which time a sample of prepared fresh semen is introduced into the uterus with a fine, soft catheter. The procedure is quite painless and similar to having a cervical smear.

Sperm production on the day of treatment

A fresh sample of semen needs to be produced by the male partner on the day of insemination, preferably after a couple of days abstinence. The sample should be dropped off at the laboratory at about 9am and within 2 hours of production.

The sample should be protected from extremes of heat and cold whilst being brought to the hospital and it is important to ensure that the pot is labelled and the top secure.

Once the sample has been received it is prepared in such a way as to extract the best swimming sperm. These are the sperm that will be used for the insemination later that same day

Semen prep for IUI

Step by step in IUI

  1. Drug treatment, to encourage 2 or 3 eggs to mature
    • Usually gonadotrophins to stimulate the growth of follicles and cause ovulation
    • When the largest follicle has reached a diameter of around 18mm a final injection (of hCH) is given; IUI is usually performed 38 hours later
  2. Throughout the drug phase treatment is monitored to measure the growth of follicles, individualise drug doses, and prevent serious side effects
    • By transvaginal ultrasound scanning (2 or 3 times during a treatment cycle
    • Sometimes by measuring hormones in a blood sample
  3. Sperm, either provided on the morning of ovulation or from a frozen sample, is prepared (washed) and inserted later that day directly into the uterus
  4. Pregnancy testing, monitoring

The chance of success

The success rates of ovarian stimulation and IUI are between 10 to 15% per cycle. The greatest chance of success is within the first 3 cycles of treatment and if on completion of these a pregnancy has not occurred then alternative assisted conception techniques such as IVF or ICSI may be suggested. The 3 cycles of treatment do not have to follow on consecutively. Many couples find treatment intensive and stressful and 'missing a month' of treatment for a holiday or just 'time out' will not affect the chance of success.

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