IUI vs IVF: Costs, Success Rates, and How to Decide
A clear comparison to help you choose
When your GP refers you to a fertility specialist, or when you start researching treatment options yourself, these two acronyms will come up fast: IUI and IVF. They sound similar but they're fundamentally different procedures, with different costs, success rates, invasiveness, and emotional tolls.
I want to give you a straight comparison — what each involves, who each is best suited for, and how to think about the decision. Because it IS a decision, and a big one.
What Is IUI?
Intrauterine insemination (IUI) is the simpler of the two. A concentrated sample of washed sperm — either from a partner or a donor — is placed directly into the uterus through a thin catheter, timed to coincide with ovulation.
The idea is straightforward: by placing sperm closer to the egg and bypassing the cervix, you increase the chances of fertilisation happening naturally inside the body. Everything else — ovulation, fertilisation, implantation — happens on its own.
A typical IUI cycle looks like this:
Monitoring — ultrasound scans and blood tests track your follicle development and predict ovulation. Some IUI cycles are "natural" (no medication), while others use mild ovarian stimulation with letrozole or clomifene to increase the number of mature follicles.
Sperm preparation — on the day of insemination, the sperm sample is "washed" in the lab. This concentrates the healthiest, most motile sperm and removes seminal fluid, prostaglandins, and debris.
Insemination — the washed sperm is drawn into a thin catheter and inserted through the cervix into the uterus. It takes about 5 minutes, feels similar to a smear test, and most women describe it as uncomfortable but not painful.
The wait — then you wait two weeks, just like any natural cycle. No bed rest needed. Normal activities are fine.
What Is IVF?
In vitro fertilisation is more involved. Eggs are collected from your ovaries, fertilised with sperm in a laboratory, and the resulting embryo is transferred back into your uterus days later.
Ovarian stimulation — daily hormone injections (gonadotropins) for 8–14 days stimulate your ovaries to produce multiple eggs instead of the usual one. You'll have regular ultrasound scans and blood tests to monitor your response. A trigger injection (usually hCG) induces final egg maturation.
Egg retrieval — 34–36 hours after the trigger, eggs are collected via a needle guided by ultrasound, through the vaginal wall. This is done under sedation and takes about 20 minutes. You'll feel groggy and potentially sore afterwards.
Fertilisation — eggs and sperm are combined in the lab (conventional IVF) or a single sperm is injected directly into each egg (ICSI — used when sperm quality is poor). The embryos are cultured for 3–5 days.
Embryo transfer — one (sometimes two) embryo is placed in the uterus via a thin catheter, similar to IUI. Any remaining good-quality embryos can be frozen for future use.
The wait — two weeks until a pregnancy test. This part is identical to IUI, and honestly, it's the hardest part of either treatment.
Success Rates: IUI vs IVF
This is where the difference is stark.
IUI success rates — approximately 10–20% per cycle for women under 35, dropping to 5–10% for women over 40. With ovarian stimulation, rates are slightly higher than natural cycle IUI. After 3–6 unsuccessful IUI cycles, most clinics recommend moving to IVF (NICE, 2013).
IVF success rates — approximately 29% per embryo transfer for women under 35 (HFEA, 2023 data). This drops to about 23% for ages 35–37, 15% for 38–39, and 9% for 40–42. Cumulative success rates — across multiple cycles using fresh and frozen embryos — are significantly higher: around 50–60% after three full IVF cycles for women under 38.
Put simply: IVF is roughly twice as effective per cycle as IUI, but it costs 4–8 times as much and is significantly more physically and emotionally demanding.
Cost Comparison
In the UK (private, per cycle):
IUI: £500–£1,500 (natural cycle on the lower end, medicated on the higher end). Donor sperm adds £500–£1,000.
IVF:£4,000–£8,000 including medications, monitoring, egg retrieval, and embryo transfer. ICSI adds £1,000–£1,500. Frozen embryo transfers are typically cheaper at £1,500–£2,500.
NHS availability: NICE recommends up to 6 cycles of IUI for unexplained infertility or donor insemination, and up to 3 cycles of IVF for women under 43 who haven't conceived after 2 years. But NHS provision varies enormously by area — some CCGs offer 3 full IVF cycles, others offer just 1, and waiting lists can be 12–18 months. Your GP can tell you what's available locally.
Which Is Right for You?
IUI is typically recommended when:
- You have unexplained infertility (no identified cause after testing)
- You're using donor sperm (same-sex couples, single parents by choice)
- Mild male factor infertility (slightly low sperm count or motility)
- Cervical mucus issues or cervical scarring
- Ovulation disorders that respond to medication
- You want to try a less invasive option before committing to IVF
IVF is typically recommended when:
- Blocked or damaged fallopian tubes
- Severe male factor infertility (very low count/motility — ICSI needed)
- Endometriosis (moderate to severe)
- Low ovarian reserve or diminished AMH levels
- Multiple failed IUI cycles (usually 3–6 attempts)
- Age over 38 (time is a factor — IVF has higher per-cycle success)
- You want to do genetic testing on embryos (PGT-A/PGT-M)
The Emotional Side
Both treatments are emotionally taxing, but in different ways.
IUI can feel frustratingly close to natural trying — the success rates aren't dramatically higher than timed intercourse, and the disappointment of a negative test after the procedure can feel worse because you "did everything right." Some women describe IUI as a limbo: too medical to feel natural, not medical enough to feel like you're really doing something.
IVF is more emotionally consuming. The daily injections, the monitoring appointments, the egg retrieval, waiting for fertilisation reports, watching embryos develop (or not) — every stage is a potential point of hope or devastation. But there's also something empowering about IVF: you're doing everything medically possible. The not-knowing is different when science is actively involved.
Neither is easy. Both are worth it if they give you your family. And there's no wrong choice here — only the choice that's right for your body, your circumstances, and your mental health.
What to Expect During Your First IUI
If you've been referred for IUI, knowing what to expect day by day takes a lot of the anxiety out of the process.
Days 1–3: Baseline. On day 1 or 2 of your period, you'll have a baseline ultrasound and blood tests. The clinic checks that your ovaries are quiet (no leftover cysts from the previous cycle) and your hormone levels are at baseline.
Days 3–12: Monitoring. If you're doing a medicated IUI (with Clomid, Letrozole, or injectable gonadotropins), you'll start medication around day 3. Unmedicated (natural) IUI simply monitors your natural cycle. Either way, you'll have 2–3 ultrasound scans to track follicle growth and 1–2 blood tests to check oestrogen levels.
Trigger day. When your lead follicle reaches 18–22mm, you'll take a trigger injection (usually Ovitrelle in the UK). This causes ovulation roughly 36 hours later. Some clinics time the trigger to your natural LH surge instead.
Insemination day. Your partner provides a sperm sample (or donor sperm is thawed), which is washed and concentrated. The actual insemination takes about 5 minutes — a thin catheter is passed through your cervix and the sperm is placed directly in your uterus. Most women describe it as similar to a smear test: uncomfortable but not painful.
The two-week wait. Then you wait. Some clinics prescribe progesterone support. You'll test about 14 days later. This wait feels longer than any other two weeks in your life. I promise you — it's the same for everyone.
Questions to Ask Your Fertility Specialist
When you're sitting in a consultation, it's hard to think clearly. Here are the questions I wish I'd asked from the start:
For IUI:
- "How many IUI cycles do you recommend before moving to IVF?" — Most specialists suggest 3–4 medicated IUI cycles. Beyond that, the cumulative probability doesn't increase much.
- "Will this be medicated or natural?" — Medicated IUI has roughly double the success rate of natural IUI, but carries a higher risk of multiple pregnancy.
- "What are your clinic's IUI success rates for my age group and diagnosis?" — Published HFEA data gives national averages, but individual clinic rates vary significantly.
For IVF:
- "What stimulation protocol do you recommend and why?" — There are several (long protocol, short/antagonist, mild stimulation). The right one depends on your ovarian reserve and previous response.
- "Do you recommend ICSI?" — In standard IVF, sperm and eggs are placed together. ICSI injects a single sperm directly into each egg. It's essential for male factor infertility but often added by default — ask whether it's genuinely needed in your case.
- "What's your policy on how many embryos to transfer?" — In the UK, single embryo transfer is standard for women under 37 to reduce twin pregnancy risk. This is a good thing.
- "What supplements do you recommend before starting?" — Many specialists recommend CoQ10 and vitamin D for at least 3 months before IVF.
Preparing Your Body for Treatment
Whether you're starting IUI or IVF, the preparation window matters. Egg maturation takes approximately 90 days, which means the lifestyle and supplement choices you make now affect the eggs you'll use in 3 months' time.
Start supplements early. CoQ10 (200–600mg daily), folate (at least 400mcg, preferably methylfolate), vitamin D (check your levels — most women in the UK are deficient), and omega-3 fatty acids all have evidence supporting egg quality.
Reduce alcohol and caffeine. The evidence on caffeine is mixed, but most fertility specialists recommend limiting it to 200mg daily (roughly one cup of coffee). Alcohol is best avoided entirely during treatment months.
Address stress proactively. I know "just relax" is the most infuriating advice in fertility. But chronic stress genuinely affects hormone levels. Find what works for you — yoga, walking, therapy, acupuncture, journaling. Not because relaxing will make you pregnant, but because you deserve to feel as supported as possible going through this.
When I was preparing for what might have been our IVF journey (before Bowie came naturally), I spent three months overhauling everything. Supplements, sleep, food, exercise. Did it work? I'll never know for certain. But feeling like I was doing everything I could gave me something to hold onto during the hardest months.
What to expect during your first IVF cycle: the day-by-day guide
The IUI walkthrough above gives you the granular detail you need. Here's the same level of detail for IVF — because knowing what's coming makes the process significantly less overwhelming.
Week 1 (Day 1–3): Your cycle starts. You'll go in for baseline scans and bloods on day 1 or 2 of your period. If everything looks clear, you start daily hormone injections (stimulation drugs). Most clinics teach you to self-inject at home — it sounds terrifying but becomes routine within 2–3 days.
Weeks 2–3 (Day 3–14): Inject at the same time each day. You'll have monitoring scans every 2–3 days (roughly 4–6 clinic visits total) so your team can track how many follicles are growing and adjust your medication dose. This is the most time-intensive phase — plan for morning appointments.
Trigger day (around Day 10–14): When your leading follicles reach 18–22mm, you'll take a "trigger shot" — a precisely timed injection that triggers final egg maturation. Your egg retrieval is scheduled exactly 36 hours later. The timing is non-negotiable, even if that means a 2am injection.
Egg retrieval (Day 12–16): A short procedure under sedation (about 15–20 minutes). You won't feel anything during it. Afterwards, expect grogginess, cramping, and bloating for 1–3 days. Most women take the day off work plus one recovery day. You'll get a call that afternoon or the next morning with your egg count.
The lab phase (Days 1–6 post-retrieval): This is the hardest wait. The lab calls with updates: Day 1 — fertilisation results (how many eggs were mature, how many fertilised). Day 3 — how many are still developing. Day 5–6 — how many reached blastocyst stage. Each call usually involves a drop in numbers. This is normal but emotionally brutal. Ask your clinic in advance when to expect calls so you're not staring at your phone all day.
Transfer or freeze (Day 5–6): If you're doing a fresh transfer, one embryo is placed in your uterus via a thin catheter (painless, no sedation needed). If your clinic recommends freeze-all, your embryos are vitrified and a frozen embryo transfer (FET) is planned for a later cycle — usually 1–2 months later.
The two-week wait: Then you wait. The pregnancy blood test is typically 10–14 days after transfer. This part is the same whether it's IUI or IVF — and it never gets easier.
The egg-to-embryo numbers: what realistic IVF attrition looks like
This is the part of IVF that almost nobody prepares you for. The success rates I quoted above are per embryo transfer — but before you get to transfer, there's a significant and completely normal drop-off at every stage.
Here's what a typical cycle looks like for a woman under 35:
| Stage | Example Numbers | What's Happening |
|---|---|---|
| Eggs retrieved | 12 | Not all follicles contain eggs |
| Mature eggs | 10 | Only mature (MII) eggs can be fertilised |
| Fertilised normally | 7–8 | Some won't fertilise even with ICSI |
| Day 3 embryos | 5–6 | Some stop dividing |
| Day 5 blastocysts | 3–4 | Only ~30–50% of retrieved eggs reach this stage |
| PGT-A normal (if tested) | 2 | 50–70% of blasts may be chromosomally normal |
For women over 38, attrition is steeper at every stage — particularly at the PGT-A step.
I share these numbers not to scare you, but because being blindsided by the drop-off is one of the most traumatic parts of IVF. Ask your consultant before retrieval what realistic numbers look like for your age and diagnosis. Knowing the range in advance doesn't make it easy — but it prevents the shock of expecting 12 chances and ending up with 2.
When IUI is costing you more than money: recognising when to move on
The guidance I shared above — 3–6 IUI cycles before considering IVF — aligns with NICE recommendations. But the decision isn't purely clinical.
Each unsuccessful IUI cycle costs 4–6 weeks of time, £500–1,500 in money, and a significant amount of emotional energy. For women over 35, time is the resource you can't get back.
The women who express the most regret in fertility communities aren't those who "jumped to IVF too early." They're those who persisted with IUI cycle after cycle because it was cheaper and less invasive, only to wish they'd moved sooner.
A practical framework:
- Under 35, unexplained infertility: 3–4 medicated IUI cycles is a reasonable trial
- Over 37, or low ovarian reserve: Consider IVF after 2–3 IUI attempts
- Blocked tubes, severe male factor, or endometriosis: IVF is usually recommended from the start
- After 3 failed medicated IUI cycles at any age: Ask your specialist directly: "Would you recommend IVF now for someone in my situation?"
The question to ask yourself: is each additional IUI cycle a reasonable step toward pregnancy, or is it a way of avoiding the bigger, scarier, more expensive thing? Both answers are valid. Just be honest about which one it is.
Fresh vs frozen embryo transfer: what you need to know
Many clinics now default to a "freeze-all" strategy, where all embryos are frozen after retrieval and the transfer happens in a later cycle. This can feel counterintuitive — you want to move forward, not wait — but the evidence supports it.
After ovarian stimulation, your hormone levels are elevated and your uterine lining may not be in its most receptive state. A frozen embryo transfer (FET) 1–2 months later allows your lining to develop in a more natural hormonal environment. Studies show FET success rates are at least equal to, and in some cases higher than, fresh transfers — particularly in cycles with a strong ovarian response or risk of ovarian hyperstimulation (OHSS).
A FET cycle is also simpler: no injections for stimulation, just oestrogen and progesterone to prepare your lining, with 2–3 monitoring scans before the transfer day. The cost is lower too (£1,500–2,500 vs a full IVF cycle).
Ask your clinic whether they recommend fresh or frozen for your situation — and why. There's no universal best answer, but understanding the reasoning helps you feel more in control of the process.
Building a realistic IVF budget: the costs the per-cycle price doesn't show
The cost comparison above covers individual cycle pricing — and those numbers are accurate. But first-time IVF patients consistently report spending significantly more than they budgeted. The gap comes from add-ons and repetition:
- Medication: £1,000–3,000 per cycle (varies with protocol and ovarian response)
- ICSI: £1,000–1,500 (often recommended even without male factor)
- PGT-A genetic testing: £2,000–3,000 per cycle
- Embryo freezing + annual storage: £500–1,000
- Frozen embryo transfer (FET): £1,500–2,500 per cycle
- Blood tests, scans, consultations: £200–500 (if not bundled)
And the reality most people don't plan for: you may need more than one cycle. National averages show many women need 2–3 full stimulation cycles.
My recommendation: budget for two full cycles plus one FET before you start. A realistic first-year UK IVF budget is £10,000–20,000 including everything. If you only need one cycle, the remaining funds become savings. If you need more, you're not scrambling mid-treatment. Some clinics offer multi-cycle packages that reduce the per-cycle cost — always ask.
The Bottom Line
IUI is simpler, cheaper, and less invasive — but less effective. IVF is more complex, expensive, and physically demanding — but significantly more successful per cycle. Many women start with IUI and move to IVF if it doesn't work. Others skip straight to IVF based on their diagnosis, age, or preference.
Talk to your fertility specialist about which makes sense for your specific situation. And whatever you decide, know that choosing treatment — any treatment — is an act of courage.
References
- Bensdorp AJ, et al. (2015). Effectiveness of IUI vs IVF in mild-to-moderate male factor infertility. The Lancet, 385(9975), 1320-1326. PubMed
- Pandian Z, et al. (2015). IUI versus IVF/ICSI for non-tubal infertility. Cochrane Database of Systematic Reviews, CD002807. DOI
- HFEA (2023). Fertility treatment 2021: preliminary trends and figures. HFEA
- NICE (2013). Fertility problems: assessment and treatment. CG156. NICE
▸Is IUI painful?
Most women describe IUI as mildly uncomfortable, similar to a smear test. The procedure takes about 5 minutes. Some experience mild cramping afterwards, but it rarely requires pain relief.
▸How many IUI attempts before trying IVF?
Most fertility specialists recommend 3–6 IUI cycles before considering IVF. NICE guidelines suggest up to 6 cycles for unexplained infertility. If you're over 38 or have a specific diagnosis like blocked tubes, your doctor may recommend skipping straight to IVF.
▸Can you do IUI at home?
No. IUI must be performed by a trained professional in a clinical setting because the catheter bypasses the cervix and enters the uterus directly. Home insemination (intracervical) is a different procedure with lower success rates.
▸What are the side effects of IVF?
Common side effects include bloating, mood swings, headaches, and injection site reactions during stimulation. Ovarian hyperstimulation syndrome (OHSS) is a risk in about 1–5% of cycles. Egg retrieval can cause cramping and light bleeding for 1–2 days.
▸Should I skip IUI and go straight to IVF?
It depends on your diagnosis and age. Blocked tubes, severe male factor, or low ovarian reserve usually mean IVF from the start. For unexplained infertility or mild male factor, 3–4 IUI cycles are reasonable at a fraction of the cost. Ask your specialist: "Given my specific diagnosis and age, what is my realistic per-cycle success rate with IUI vs IVF?" If IUI gives you 5% and IVF gives you 30%, the maths changes quickly.
▸My clinic retrieved 15 eggs but I only got 2 embryos. Is that normal?
Yes. The attrition funnel is real and normal. Of 15 eggs, perhaps 12 will be mature, 8–10 may fertilise, 4–6 may still develop by day 3, and 2–4 might reach blastocyst by day 5. With PGT-A, you may lose more. Expect about 30–50% of retrieved eggs to become blasts. Ask your consultant before retrieval what realistic numbers look like for your age.
▸Is a fresh or frozen embryo transfer better?
Studies show frozen embryo transfer (FET) success rates are at least equal to, and sometimes higher than, fresh transfers. After stimulation, your body needs recovery time and your lining may not be optimally receptive. A FET 1–2 months later allows a more natural environment. Many clinics now default to freeze-all. Ask yours what they recommend for your situation.
▸How much should I really budget for IVF in the UK?
The base IVF cycle cost of £4,000–8,000 is accurate, but real-world spending is higher once you add medications (£1,000–3,000), ICSI (£1,000–1,500), PGT-A (£2,000–3,000), freezing and storage (£500–1,000), and FET cycles (£1,500–2,500). Budget for two full cycles plus one FET: a realistic first-year budget is £10,000–20,000.
Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. If you are experiencing a medical emergency, contact your local emergency services immediately.
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