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Understanding Treatment

IUI

What intrauterine insemination is and how the process works.

  • 2 minread
  • 2sections
  • 1myth checked
  • 4sources

IUIintrauterine inseminationtreatmentdonor sperm

Illustration of intrauterine insemination, with a thin catheter placing sperm into the uterus.
Illustration of intrauterine insemination, with a thin catheter placing sperm into the uterus.

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IUI (intrauterine insemination) is one of the fertility treatments people hear about first. It is less involved than IVF, and it helps to understand exactly what happens and who it may be suitable for.

Kara explains

In IUI, a sperm sample is prepared in the laboratory and then placed directly into the uterus using a thin, soft catheter, timed around ovulation. Fertilisation still happens inside the body.

The process

The sperm sample is prepared (“washed”) in the lab, and the insemination itself is usually a short procedure.

Cycles may be natural (with no fertility medication) or medicated, using tablets or hormone injections to encourage one or a few follicles to grow. Ovulation timing is monitored, the sperm sample is prepared (“washed”) in the lab, and the insemination itself is usually a short procedure. Fertility medication used with IUI raises the chance of twins or triplets, particularly injected hormones, which is why these cycles are monitored with scans. If too many follicles grow, the usual options are to convert the cycle to IVF, or to cancel it and avoid sex (or use condoms). If protection fails, there is a real risk of a multiple pregnancy.

Who may be offered IUI

Whether IUI is suitable depends on individual circumstances, including tubal health and semen characteristics.

Whether IUI is suitable depends on individual circumstances, including tubal health and semen characteristics. At least one open fallopian tube is usually needed. It may be considered, for example, when using donor sperm. For couples with unexplained infertility, IUI is most useful when it is combined with fertility medication, and guidelines now include this combination as an option before IVF. The right choice depends on your age, your tests and your preferences.

Myth vs evidence

Myth

“IUI and IVF are basically the same.”

Evidence

In IUI, fertilisation happens inside the body. In IVF, eggs are collected and fertilised in the laboratory.

Take to your appointment Ask your healthcare professional
  1. Why is IUI being suggested for us, rather than another option?
  2. Will this be a natural or medicated cycle?
  3. How many cycles would you suggest before reviewing the plan?

Words you may hear

Sperm preparation (washing)
Laboratory processing that separates sperm from seminal fluid.
Catheter
A thin, flexible tube used to place the sample in the uterus.
Kara’s key takeaway

IUI places prepared sperm closer to the egg at the right time. Fertilisation still happens naturally inside the body.

Watch with Kara

Videos on this topic are coming to the channel:

  • What Is IUI?
  • IUI Step by Step
  • Natural or Medicated IUI: What’s the Difference?

See the video schedule

It takes two
Concept illustration, not to scale.

Male fertility belongs in the same conversation. These illustrated guides pair with this topic:

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Sources 4 studies and guidelines Show the research