Bath Fertility

01761 434 464


IUI (Intra-uterine insemination) is a fertility treatment that involves placing motile sperm inside the uterus close to your eggs when you ovulate.

This maximises the chances of sperm reaching an egg at the right time for fertilisation to occur. Although the procedure itself is straightforward, the timing is very important. Some women can have IUI treatment in their natural cycle, whilst others may need low dose fertility drugs to stimulate egg production. This will be discussed with you at your consultation.

Who is IUI suitable for?

IUI is suitable when women don’t have tubal damage, and for heterosexual couples the man should have a normal or only mildly suboptimal semen analysis. IUI is also used for donor sperm treatments.

How does IUI work?

If you don’t need to take fertility drugs the IUI treatment will take place around the time you’d naturally be ovulating, detected with an ovulation predictor kit.

For those who don’t ovulate, before commencing treatment an ultrasound scan is carried out. Providing this is normal your treatment is started with a low dose of fertility drugs to stimulate the production of one or more follicles (eggs grow in follicles).

A week after you start the fertility drugs another scan is carried out to check how many follicles are growing. We’re aiming for a maximum of 2 large follicles and no more than 2 smaller. If your scan shows this, a final injection of a different hormone is required that causes ovulation 34–40 hours later. Insemination will be timed to coincide with this.

Partners will need to attend the clinic on the day of IUI treatment to produce a sperm sample for preparation by the laboratory.

The insemination is done using a fine catheter that is passed into your uterus through the cervix. The washed, prepared sperm is then injected slowly using a syringe. The procedure itself only takes a few minutes. You can do a home pregnancy test 2 weeks after IUI.

What are the IUI success rates?

Pregnancy rates for IUI using a partner’s sperm are around 15% per treatment cycle. This is lower than with IVF/ICSI, as we’re not able to be certain that fertilisation has taken place following insemination. For this reason IUI treatment is usually limited to 3 cycles of treatment before we recommend progressing to IVF.

Pregnancy rates for IUI using donor sperm are around 25% per cycle.

If you’d like more information about IUI or any other fertility treatment, please don’t hesitate to contact our friendly team. Simply give us a call on 01761 434464 or email us at We will be happy to answer any questions you may have.