Understanding IUI vs IVF: Costs, Success Rates and How to Choose in the UK

When comparing IUI vs IVF, the key difference is where fertilisation happens: with IUI (intrauterine insemination), washed sperm is placed directly into the uterus and fertilisation occurs naturally inside the body, while with IVF (in vitro fertilisation), eggs are retrieved and fertilised with sperm in a laboratory before the embryo is transferred to the womb. IVF has significantly higher success rates per cycle but costs three to five times more than IUI. Your doctor will recommend one or the other based on your age, fertility diagnosis, how long you have been trying and whether you need donor eggs or sperm.

What Is IUI and How Does It Work?

IUI, also called artificial insemination, is the simpler of the two treatments in the IUI vs IVF comparison. The procedure is timed to coincide with ovulation so that sperm has the best chance of reaching the egg in the fallopian tubes. The insemination itself takes just a few minutes and is typically painless, though some women report mild cramping similar to period pain.

Before IUI, the sperm sample — from a partner or a sperm donor — is washed and filtered in a laboratory to concentrate the fastest and healthiest sperm. This washing process removes seminal fluid and non-motile sperm, increasing the odds of fertilisation. Some clinics combine IUI with mild ovarian stimulation using fertility drugs such as clomifene or gonadotrophins, which encourage the production of one or two mature eggs per cycle. Stimulated IUI cycles have higher success rates than natural-cycle IUI, but also carry a slightly increased risk of multiple pregnancy.

IUI is suitable for single women and lesbian couples who need donor sperm to conceive, heterosexual couples with unexplained infertility or mild male factor infertility (low sperm count or motility issues), and couples who are unable to have sexual intercourse due to physical disability or psychological conditions. At least one healthy and open fallopian tube is required for IUI to work.

What Is IVF and How Does It Work?

IVF is the more complex treatment in the IUI vs IVF equation. Eggs are collected from the ovaries, fertilised with sperm in a laboratory dish, and the resulting embryos are transferred back into the uterus. Unlike IUI, fertilisation takes place outside the body, giving clinicians full control over which eggs and sperm are used and allowing embryo quality to be assessed before transfer.

An IVF cycle typically takes 4 to 6 weeks and involves several stages: ovarian stimulation with injectable hormone medications for 10 to 14 days, monitoring via blood tests and ultrasound scans, egg retrieval under sedation (a minor procedure lasting 15 to 20 minutes), laboratory fertilisation, embryo culture for 3 to 5 days, and embryo transfer. Any additional viable embryos can be frozen for future use, reducing the cost and physical demands of subsequent cycles.

IVF is recommended when IUI has failed after multiple cycles, when there are blocked or damaged fallopian tubes, moderate to severe male factor infertility, endometriosis, or diminished ovarian reserve. It is also the only option when donated eggs are required. Lesbian couples who want both partners to be physically involved in the pregnancy can choose reciprocal IVF (shared motherhood), where one partner’s eggs are fertilised and the embryo is transferred to the other partner’s womb — read more about how lesbian couples decide who will conceive.

How Do IUI vs IVF Success Rates Compare?

Success rates are one of the most important factors when weighing IUI vs IVF. According to the HFEA, IVF birth rates per fresh embryo transfer average approximately 31% nationally, rising to 41% for women aged 18 to 34. IUI success rates are considerably lower, averaging around 12 to 15% per cycle with donor sperm and 10 to 12% per cycle with partner sperm.

However, cumulative success rates paint a more nuanced IUI vs IVF picture. Because IUI cycles are faster and less physically demanding, many women undergo several cycles in a shorter time. Research published in Human Reproduction found that IUI achieves a cumulative pregnancy rate of around 40% after six cycles. IVF, meanwhile, achieves cumulative live birth rates of approximately 65% after three full cycles for women under 35.

Age is the single most significant factor affecting both treatments in the IUI vs IVF comparison. For IVF, the NHS reports birth rates of approximately 32% for women under 35, 28% for those aged 35 to 37, 21% for ages 38 to 39, and 14% at 40 to 42. IUI success rates drop more steeply after 35, partly because IUI relies on natural fertilisation within the body and cannot bypass issues like declining egg quality.

How Do IUI vs IVF Costs Compare in the UK?

Cost is often the deciding factor when choosing between IUI vs IVF. A single IUI cycle at a private UK clinic typically costs £800 to £1,500, including monitoring, sperm preparation and the insemination procedure. If you use donor sperm from a sperm bank, add £500 to £1,200 per vial. A full IVF cycle costs significantly more, typically £5,000 to £8,000, including medication, egg retrieval, laboratory fees and embryo transfer.

For those using donor sperm, the IUI vs IVF cost calculation should compare the total cost to pregnancy rather than the cost per cycle. If IUI requires four to six cycles to achieve pregnancy while IVF might succeed in one or two, the overall investment can be surprisingly similar. The HFEA has noted a growing trend since 2021: more female same-sex couples and single women are now choosing IVF as their first treatment rather than starting with IUI, partly for this reason.

A more affordable alternative is home insemination with a known donor, which can cost as little as £30 for a syringe kit. However, home insemination has lower success rates (approximately 10 to 15% per cycle) and carries important legal implications — the donor may be considered the legal father if conception takes place outside a licensed clinic.

Can You Get IUI or IVF on the NHS?

NHS access to both treatments in the IUI vs IVF decision depends on where you live and your personal circumstances. According to the NHS, IUI is not routinely funded by most Integrated Care Boards (ICBs) in England, and many patients need to self-fund the treatment privately. NICE guidelines recommend that women under 43 should be offered IVF after demonstrating they cannot conceive through less intensive methods.

For female same-sex couples and single women, most ICBs require 6 to 12 self-funded IUI cycles before the NHS fertility treatment pathway opens. According to GOV.UK data on NHS-funded IVF, this can represent an upfront investment of £5,000 to £25,000 before any NHS-funded treatment becomes available. Heterosexual couples typically qualify after two years of unsuccessful unprotected intercourse. Access is more equitable in Scotland, where up to six IUI cycles are funded for all patient groups.

When Should You Switch from IUI to IVF?

Knowing when to move from IUI to IVF can save time, money and emotional energy. When weighing IUI vs IVF timelines, most fertility specialists recommend considering the switch in the following situations:

• You have completed 3 to 6 unsuccessful IUI cycles — continuing beyond six cycles of IUI rarely improves cumulative success rates significantly
• You are over 38, as IVF offers higher per-cycle success rates that can offset the effect of declining egg quality
• A fertility assessment reveals blocked fallopian tubes, severe endometriosis or a very low sperm count (below 5 million motile sperm per millilitre)
• You need donated eggs, which can only be used through IVF
• You want to freeze embryos for future use, for example to plan siblings at a later date

Your fertility specialist can help you weigh the IUI vs IVF decision based on your individual test results, age and priorities. On CoParents.co.uk, a co-parenting and sperm donation platform with over 150,000 users since 2008, many members share their experiences of both treatments and connect with sperm donors who can support their journey regardless of which treatment path they choose.

How Do You Choose a Sperm Donor for IUI or IVF?

Whether you opt for IUI or IVF, the IUI vs IVF choice does not change the need for a sperm donor if you are a same-sex couple or single woman. You can source donor sperm from an HFEA-licensed sperm bank, where all donors are screened for infectious diseases, genetic conditions and sperm quality. Alternatively, you can find a known donor through a platform like CoParents.co.uk or within your personal network. If you use a known donor, the HFEA strongly recommends having the insemination performed at a licensed clinic to ensure the donor has no legal parental rights over any child conceived.

The type of sperm you purchase from a bank also matters. IUI-prepared (washed) sperm is ready for intrauterine use, while ICI-prepared sperm is designed for intracervical insemination and can also be used in IVF. Choosing the right preparation type ensures the best match for your treatment method. For more on the differences, read our guide to ICI vs IUI donor sperm.

Frequently Asked Questions About IUI vs IVF

Is IUI or IVF more painful?

IUI is generally painless and takes only a few minutes, with some women experiencing mild cramping. IVF involves daily hormone injections for 10 to 14 days and an egg retrieval procedure under sedation, which can cause bloating, tenderness and short-term discomfort. Most women describe IVF as manageable but more physically demanding than IUI.

How many cycles of IUI should I try before switching to IVF?

Most fertility specialists recommend trying 3 to 6 IUI cycles before considering IVF. If you have not conceived after six cycles, the chance of success with further IUI cycles drops significantly. For women over 38, moving to IVF sooner — after 3 cycles — is often advised.

Can I do IUI at home instead of at a clinic?

Home insemination (intracervical insemination) is possible using a syringe kit, but it is not the same as clinical IUI, which places washed sperm directly into the uterus. Home insemination has lower per-cycle success rates. Importantly, if you are not married or in a civil partnership, only treatment at an HFEA-licensed clinic ensures both partners are recognised as legal parents from birth.

Which is better for lesbian couples: IUI vs IVF?

Both are effective options for the IUI vs IVF question. Many lesbian couples start with IUI because it is less invasive and more affordable. If IUI is unsuccessful after several cycles, or if one partner wants to provide eggs while the other carries the pregnancy (reciprocal IVF), then IVF becomes the better choice. The right answer depends on your age, fertility health and personal preferences.

Ready to start your journey to parenthood? Whatever your IUI vs IVF decision, join CoParents.co.uk for free to find sperm donors and co-parents who match your family vision.