IVF vs IUI: How the Two Fertility Treatments Compare on Process, Suitability, Success and Cost

IVF and IUI are both fertility treatments, but they work very differently: IUI places prepared sperm directly into the womb so fertilisation happens inside your body, while IVF combines egg and sperm in a laboratory and transfers a resulting embryo. That single difference shapes everything else: how involved each treatment is, who it suits, how often it works, and what it costs. I went through several rounds of treatment before our daughter arrived, and understanding this comparison early would have saved me a lot of confusion.

What each treatment involves

IUI is the simpler of the two: it adds a prepared, concentrated sample of sperm into the womb at the time of ovulation, then lets nature take over. It can be done in a natural cycle or with mild medication to encourage ovulation, and the insemination itself is a quick procedure, similar to having a smear test, with no sedation.

IVF is a multi-stage process over roughly 4 to 6 weeks. It starts with about two weeks of hormone injections to stimulate the ovaries, then egg collection under sedation (a day case lasting around 20 to 30 minutes), fertilisation in the laboratory, a few days of embryo development, and finally embryo transfer, followed by the two-week wait. Our full guide to how IVF works step by step walks through each stage.

Who each treatment suits

IUI tends to suit specific situations rather than everyone. NICE notes that IUI is offered in particular circumstances, such as people who cannot have vaginal intercourse, and it is commonly used with donor sperm for single women and female same-sex couples. It can also be a reasonable first step for some couples with mild male factor infertility or unexplained infertility, where the basics (open fallopian tubes and a reasonable sperm count) are in place.

IVF is the broader treatment and is recommended where IUI is unlikely to work: blocked or damaged fallopian tubes, more significant sperm problems, or after IUI or other treatments have not succeeded. Because it bypasses the tubes entirely, it covers situations IUI cannot. Timing matters too: NICE suggests investigating after about 12 months of regular unprotected sex without conceiving, or about 6 months if you are over 35, and IVF is typically considered for unexplained infertility once that period has passed.

How success per cycle compares

IVF has a higher success rate per cycle than IUI for most people, and age is the strongest predictor for both. Success is highest under about 35 and declines steadily, more sharply from the late 30s. When you compare any two figures, check what each one actually counts: a rate can be measured per cycle started or per transfer, and per pregnancy or per live birth. Live birth is the lower number and the one that matters, and standardised HFEA data is more comparable than clinic marketing.

It also helps to think cumulatively. Many people who succeed do so after more than one attempt with either treatment, so a single low-looking per-cycle figure does not tell the whole story. Our guide to IVF success rates explains how to read these numbers carefully.

What each treatment costs

Cost is often where the contrast feels starkest. In the UK a single cycle of IUI is usually a few hundred pounds, while one cycle of IVF commonly costs around 5,000 to 8,000 pounds before medication, freezing and any add-ons are included. NHS funding exists for both but varies by area and eligibility, so many people pay privately for at least part of their treatment.

The cheaper price per IUI cycle can be misleading, though: because it works less often per cycle, several rounds can add up, and some people spend months on IUI before moving to IVF anyway. Weighing total likely cost, not just the headline price, matters. We cover the full picture in how much IVF costs.

Choosing between them, and when to ask

For me, the most useful thing was treating this as a sequence rather than a single fork in the road. Plenty of people start with a few cycles of IUI when it is clinically suitable and step up to IVF if it does not work; others go straight to IVF because their diagnosis calls for it. The right order genuinely depends on your age, your test results and how long you have been trying, which is why a personalised conversation with a specialist beats any general rule.

If you are unsure where to start, do not delay. Fertility can be time-sensitive, and the earlier you are assessed the more options you tend to have; see our guide on when to see a doctor about fertility.

This article is general information and support, not medical advice. For guidance on your own situation, please consult your GP or a fertility specialist.