IVF vs IUI: Which Fertility Treatment Is Best for You?

By Dr Thanos Papathanasiou, CEO & Medical Director, Bourn Hall Fertility Clinic, UK

One of the first questions many people ask is whether to try intrauterine insemination (IUI) or go straight to in vitro fertilisation (IVF). 

This isn’t just a medical choice – it’s about values, priorities and how long someone feels able to keep trying. Both treatments can lead to a baby, but the paths are different.

Since the first IVF baby was born in 1978, more than 12 million babies worldwide have been born through IVF. What began as an experimental procedure is now one of the most widely used medical treatments in the world.

Choosing between IVF and IUI 

Choosing between IVF and IUI isn’t about finding the ‘perfect’ treatment, but about matching the right approach to your age, diagnosis, time frame and feelings.

When both IVF and IUI are possible

More often, both treatments are technically feasible. This is typically the case in unexplained infertility or when sperm counts are normal. Then the choice depends on what matters most to you.

IUI may also be appropriate when intercourse is difficult or not possible, or when sperm parameters are only slightly below average rather than significantly impaired. In these situations, IUI can act as a first step before considering more involved treatments.

IUI and the idea of ‘natural’ conception

One reason people lean toward IUI is that it feels ‘closer to natural’. Fertilisation happens inside the body rather than in a laboratory. For many, this feels less medical and therefore more comfortable.

It’s important, though, to be realistic about what IUI involves. Medical IUIs are not the same as home inseminations. They often include hormone medication to stimulate the ovaries, several ultrasound scans, sperm preparation and then the insemination itself, performed by a clinician. 

In that sense, IUI is not truly ‘natural’, though it may still feel more aligned with nature than IVF.

IUI cycles are carefully timed with ovulation. Ultrasound monitoring is usually used to track follicle growth so that insemination can take place when the egg is ready, offering structure and reassurance while still keeping the process relatively simple.

For younger women with good ovarian reserve, IUI can be a perfectly valid first step – particularly if they value a lighter-touch treatment.

When IVF is the only option

In some cases, there is no real decision to make. If sperm counts are very low, IVF with intra-cytoplasmic sperm injection (ICSI) is the only realistic way forward. 

Similarly, if the fallopian tubes are blocked, sperm and egg cannot meet naturally, so IUI cannot be offered.

The data: What are people choosing?

Recent HFEA data from 2023 underline how IVF is increasingly used in the UK: over 77,500 IVF cycles were carried out by around 52,400 patients, resulting in approximately 20,700 babies born via IVF. 

IVF births now account for about 3.1% of all UK births – roughly one in every 32 babies. For women aged 40-44, 11% of live births were a result of IVF in 2023.

By contrast, donor insemination (DI, which is a form of IUI when donor sperm is used) resulted in about 5,500 cycles and 820 babies born in the same year. Partner-sperm IUI data are less prominently reported, but the overall scale is much smaller than IVF.

IVF vs IUI success rates: why they differ

At Bourn Hall, IVF tends to be significantly more successful than IUI.

• IVF gives multiple chances from one cycle. Several eggs are usually collected, and some develop into embryos. The best embryos are chosen for transfer, and extra embryos can be frozen for later use. By contrast, IUI relies on the single egg released that month.
• IVF allows embryo selection. Embryologists can prioritise embryos with the highest developmental potential, something that IUI cannot offer.

For women under 35, around 60% of Bourn Hall patients will have a baby from a single egg retrieval, compared with no more than about 15% per IUI attempt. The comparison is not exact – IVF success is often quoted per retrieval, not per transfer – but the pattern is clear across ages: IVF is more powerful.

Time, egg quality and ovarian reserves

It is also important to consider time. Fertility treatment can take months or even years. While treatment is ongoing, egg quality continues to decline. This means that delays – whether through repeated IUIs or breaks between treatments – can reduce the overall chances of success.

For single women in particular, ovarian reserve plays an important role in choosing between IUI and IVF. Women under 35 with good ovarian reserve may have reasonable chances with IUI, whereas women over 35 often experience higher success with IVF from the outset. IVF also offers the opportunity to freeze embryos, which can be especially helpful for single women planning more than one child in the future.

Emotional impact: fewer failures, less trauma

Every negative pregnancy test is emotionally draining. IVF, by being more powerful, can reduce the number of failed cycles needed before success. That does not mean IVF is easy – it requires injections, procedures, and a heavier upfront burden. But many patients find that fewer failed attempts overall means less cumulative stress and less time lost.

Emotional support is also essential. If treatment doesn’t work straight away, counselling and dedicated nurse or donor teams can help patients process disappointment, explore next steps and feel ready – emotionally as well as physically – for whatever comes next.

Safety and risks

The main risk to baby health is multiple pregnancy. Twins and triplets carry higher risks of prematurity and complications. IVF allows tight control by transferring a single embryo. The small chance of an embryo splitting (about 1-2%) exists regardless of treatment.

With IUI, the picture is mixed.

• A natural cycle IUI, without fertility drugs, has a very low risk of multiples but also low success.
  
• A stimulated IUI, using mild hormone medication, improves the chance of success but increases the risk of twins or triplets. Clinics usually cancel cycles if too many eggs develop, but the control is not as precise as with IVF.

It is also fair to say that IVF itself has risks – ovarian hyperstimulation, egg collection procedures, and the stress of more intense treatment. Neither pathway is risk-free; the differences are in the type of risks.

Other factors to consider

Alongside the decision to have fertility treatment, there are a few other factors you’ll need to consider to ensure you’re on the right path for your needs and help you prepare for the journey. 

Cost of IVF vs IUI

One cycle of IUI costs less than one cycle of IVF. That is why IUI often feels like the “gentler” starting point.

But if the endpoint is to have a baby, not just to “try once,” the equation changes. Several IUIs followed by IVF can add up to the same or more than starting IVF directly.

At Bourn Hall, we have designed multi-cycle IVF packages to reduce the burden of treatment. These packages spread the cost across several cycles and include unlimited frozen embryo transfers, so patients who create multiple embryos can use them without extra charges. This makes it easier to commit to single embryo transfer, avoiding the risks of multiple pregnancy without feeling pressured to “use everything at once.”

The package is available to anyone who wishes to plan their treatment in this way, without needing medical approval. It is part of our effort to create options that add value and reduce the stress of treatment, not just financially but emotionally too.

For women who meet certain criteria, egg sharing can also reduce the cost of IVF. In these programmes, a patient donates some of her eggs to help another family and receives a significantly discounted or even free IVF cycle. For the right individual, this can make IVF more accessible while supporting someone else on their fertility journey.

IVF and family-building potential

IVF offers some advantages beyond the immediate cycle. Many patients create more embryos than they need at first, and these can be frozen. That gives them the option of another baby later without starting a full new cycle.

IVF can also be used proactively. For single women, this long-term planning aspect can be particularly meaningful. Creating embryos at a younger age, when egg quality is better, often preserves options for future treatment and can reduce pressure to complete family building quickly.

PGT-A: an option some patients value

Another topic that often comes up is PGT-A (preimplantation genetic testing for aneuploidy). It involves testing embryos for chromosomal differences before transfer.

• What PGT-A can do: It helps identify embryos that are very unlikely to develop into a baby, which can reduce the number of unsuccessful transfers. For some patients, this means fewer negative tests, less waiting, and less emotional burden. Many also value the sense of control it provides.
  
• What it does not do: PGT-A does not increase the overall chance of a baby. This is why the National Institute for Health and Care Excellence (NICE) does not currently recommend it for routine use.
  
• When it may be considered: PGT-A may be more relevant for patients with repeated unsuccessful transfers or recurrent miscarriage, or those who want to minimise the number of attempts (especially when they have created supernumerary embryos). It is an option, not a requirement, and should be weighed carefully in discussion with your clinician.

Using donor sperm with IUI or IVF: is there a difference?

For single women and same-sex female couples, the same principles apply. Being otherwise healthy at 40 does not reverse the effect of age on eggs, so IUI is less likely to succeed. Some still choose to begin with IUI for its simplicity or because it aligns with NICE’s recommendation, particularly when they are younger and have good ovarian reserve.

However, as age increases, or when someone wants to move forward more quickly, IVF can offer clearer advantages. IVF provides higher success rates per attempt, greater control and the option to create and store embryos for future use. 

For same-sex female couples, IVF also enables shared motherhood, where one partner’s eggs are used, and the other carries the pregnancy – a meaningful way for both partners to share in the family-building journey.

Planning treatment with donor sperm

If you’re planning treatment with donor sperm, a dedicated donor team can guide you through the process, including choosing a donor, understanding legal implications and coordinating IUI or IVF using screened, regulated donor sperm.

Using a licensed UK clinic also provides crucial legal and medical protections. Donor sperm is rigorously screened, frozen and quarantined before use, and donors undergo repeat testing. Legal parenthood is clearly defined, donors have no parental rights and there is a limit on how many families a donor can help – protections that are not available when sperm is sourced informally or online.

National guidance: what’s recommended?

NICE’s latest draft guidance recommends IVF for heterosexual couples who have tried with regular intercourse and meet the criteria. For single women and same-sex female couples using donor sperm, NICE recommends starting with IUI.

It’s worth noting that NICE does not specify an age limit for donor IUI. From our experience at Bourn Hall, however, once a woman is 38 years or older, the chance of success with IUI – donor or partner – becomes quite low. 

Because of this, we generally advise against IUI beyond that age if success, speed and avoiding repeated failure are the priority. Exceptions exist, but in most cases, IVF provides the more effective option.

Making the right choice

There is no single ‘best’ treatment. Both IUI and IVF are valid. The key is to align the medical facts with what matters most to you: staying closer to natural conception, maximising success, limiting risks, minimising costs, or building for the future.

What matters above all is not losing time, not accumulating trauma through repeated failures, and not delaying unnecessarily. That balance – between evidence and personal priorities – is the essence of good fertility care.