A single IUI cycle has an 8–20% live birth rate depending on age and diagnosis, while a single IVF cycle reaches 30–55% for women under 35. But comparing those two numbers head-to-head is misleading — cost, invasiveness and cumulative odds change the picture completely.
This guide breaks down the real data by age and diagnosis and shows what it means for your specific situation.
What Are the Success Rates by Age?
Live birth rates per cycle for both treatments drop sharply with age, as the table below shows based on CDC and SART data [1][2]:
| Age | IUI (per cycle) | IVF (per intended egg retrieval, all transfers) |
|---|---|---|
| Under 35 | 15–20% | 50–55% |
| 35–37 | 10–15% | 38–42% |
| 38–40 | 8–12% | 24–28% |
| 40–42 | 5–8% | 8–12% |
| Over 42 | 2–4% | 3–5% |
Four caveats matter more than the raw numbers:
- IUI rates cover all cycles, not just the first — each IUI attempt has roughly the same odds.
- IVF rates are per intended egg retrieval, counting every transfer from that retrieval (fresh plus any subsequent frozen transfers). For a single embryo transfer instead, the under-35 figure is about 42-47% — roughly 6-8 points lower, because each transfer counts only one chance.
- Cumulative success matters most. Three IUI cycles reach a 30–40% cumulative pregnancy rate in younger patients [1], and three IVF cycles push cumulative success above 80% under 35 [2].
- Diagnosis can outweigh age. Severe male factor or bilateral tubal blockage collapses IUI success but barely dents IVF with ICSI.
Is IUI or IVF More Successful?
IVF wins on per-cycle success in every age group and diagnosis — for a woman under 35, one IVF cycle is roughly three times as likely to produce a live birth as one IUI cycle. How you measure “more successful,” though, changes the winner:
| Metric | Winner | Why |
|---|---|---|
| Per-cycle success rate | IVF | 3–5× higher than IUI |
| Cost per live birth | Depends on age | Under 35, IUI can be more cost-effective; over 38, IVF is cheaper per live birth because IUI rates are too low |
| Time to pregnancy | IVF | Higher per-cycle odds mean faster success |
| 3-cycle cumulative success | IVF | ~80% vs ~35% under 35 |
| Risk-adjusted success | Each has advantages | IUI carries no OHSS risk, no multiples risk from transfer and no procedure |
The gap narrows for some subgroups: with unexplained infertility and good ovarian reserve (AMH > 2.0), IUI combined with oral or injectable ovulation induction can reach 18–22% per cycle.
Why Do Doctors Recommend Trying IUI First?
Most reproductive endocrinologists suggest 3–6 IUI cycles before IVF — not because IUI wins on success rates, but on the risk-benefit-cost equation.
“Most patients with unexplained infertility are offered three to six cycles of IUI before moving to IVF, because the cumulative success curve flattens after about four attempts.” — American Society for Reproductive Medicine (ASRM) patient guidance [1], as cited by ProIVF
Cost is the biggest factor. An IUI cycle runs $300–$1,000 plus medication, while a full IVF cycle costs $15,000–$25,000 [3][4]. For unexplained or mild male factor infertility, a few IUI attempts can reach a reasonable cumulative pregnancy rate without IVF’s financial and physical burden.
IUI is far less invasive. No surgical retrieval, no anesthesia, no OHSS risk and fewer monitoring visits — most patients keep working normally through a cycle.
IUI doubles as a diagnostic tool. How the ovaries respond during IUI stimulation tells the doctor about egg quality and ovarian function, information that can shape a later IVF protocol.
Some patients should skip IUI entirely:
- Bilateral tubal blockage or severe tubal disease
- Severe male factor infertility (sperm concentration under 5 million/mL)
- Age 40 or older
- Stage III–IV endometriosis
- Three or more prior failed IUIs
For these groups IUI success is so low that going straight to IVF makes sense both medically and financially.
What Are the Downsides of IUI?
IUI’s lower cost and gentleness come with five real limitations:
- Low per-cycle ceiling. Even under ideal conditions IUI tops out near 20% per cycle, and below 10% for many patients over 38.
- No help for tubal or severe male factor. IUI cannot bypass blocked tubes or compensate for very low sperm counts — with a structural problem it offers no advantage over timed intercourse.
- Multiples risk with injectables. IUI with gonadotropins (FSH) carries a 10–30% twin rate and 3–5% triplet rate, far above IVF with single embryo transfer, where multiples are largely controllable.
- Emotional attrition. Each negative IUI hits as hard as a failed IVF, and 3–6 consecutive months of failures can exhaust patients more than one failed IVF followed by a retry.
- Time cost. Three IUI cycles take 3–4 months; one IVF cycle from start to transfer takes 4–6 weeks. Patients who end up needing IVF often regret the months spent on low-odds IUI attempts.
How Successful Is IUI on the First Try?
First-attempt IUI success runs 8–20%, with most studies reporting 12–15% for women under 35 — essentially the same as any single IUI cycle, because trying before does not change the odds.
The key data points:
- Unexplained infertility, under 35: ~15–18% live birth on the first IUI
- Mild male factor, any age: ~10–14%
- Age 38–40, unexplained: ~6–8%
- Injectables vs oral meds: FSH-based IUI lifts first-cycle success 2–5 percentage points but costs 5–10× more in medication
“The first IUI has the best chance” is a common misconception. Unlike IVF — where embryologists select the best-looking sperm and eggs and the doctor adjusts each protocol — every IUI attempt carries the same statistical odds. Cumulative rates rise only because each cycle is another roll of the dice, not because later tries succeed more easily.
Three Patients, Three Paths
Case 1: IUI success on the second attempt
Sarah, 32, tried IUI at Cleveland Clinic for unexplained infertility: her first $850 cycle failed, her second worked, and she delivered at 33.
Sarah, 32 — Cleveland Clinic, Ohio, USA; unexplained infertility. After 18 months without pregnancy, every test came back normal and her doctor prescribed three IUIs before considering IVF. Her first cycle — letrozole, day-12 monitoring, intrauterine insemination — cost $850 and failed. “I couldn’t resist testing at home before my blood draw. White. I took the negative harder than expected — I thought young and healthy meant first-time success,” she recalls. Her second IUI, same protocol, worked, and she delivered at 33.
Case 2: Three failed IUIs, then IVF success
Amanda, 38, spent about CAD 3,200 on three failed IUI cycles before switching to IVF, which succeeded with a single frozen transfer at roughly CAD 18,000 total.
Amanda, 38 — Create Fertility Centre, Toronto, Canada; diminished ovarian reserve. With an AMH of 0.8 ng/mL her doctor warned IUI odds were poor, but she tried three cycles anyway, spending about CAD 3,200. All failed. “I wish I hadn’t wasted those four months — every negative test reminded me time was running out.” She moved to IVF on a mild protocol using only 150 units of FSH, less than half a conventional dose: 6 eggs, 2 blastocysts, one failed fresh transfer, then a successful frozen transfer. Total IVF cost: roughly CAD 18,000. “When they said only six eggs, I thought that was it. One passed PGT screening — holding my daughter now, I really regret those four months on IUI.”
Case 3: Straight to IVF for tubal factor
Jennifer, 34, skipped IUI because of bilateral tubal blockage; after an eight-month NHS waitlist her funded IVF cycle (£0 out of pocket) ended in a live birth on the first fresh transfer.
Jennifer, 34 — Guy’s Hospital Fertility Centre, London, UK; bilateral tubal blockage. An HSG confirmed both tubes blocked, and her doctor said IUI would offer nothing. She joined the NHS IVF waitlist: after eight months, her funded cycle cost £0 out of pocket (her region covers up to 3 cycles), and the first fresh transfer ended in a live birth. “The eight-month wait was hard, but the two-week wait was the real trial — counting down from transfer to the day-12 test. I never hesitated about skipping IUI; with blocked tubes, IVF was the only option.”
FAQ
Q: How many IUI cycles should I try before IVF?
A: Most guidelines recommend 3–6 cycles, and the success curve flattens after about 4 — beyond that, extra attempts add little. If four IUIs have failed, moving to IVF is the data-supported next step.
Q: Does IUI success increase with each cycle?
A: No. Unlike IVF, where protocols are adjusted after each cycle, every IUI attempt carries the same per-cycle odds — roughly 8–20% depending on age and diagnosis.
Q: What is the success rate of IUI with donor sperm?
A: Donor-sperm IUI has the highest IUI rates of all: about 15–22% per cycle under 35 when the recipient has no fertility issues [1]. Most same-sex couples conceive within 3–4 attempts.
Q: Can IUI work with low sperm count?
A: IUI needs at least about 5–10 million motile sperm after washing. Below that threshold, per-cycle success drops under 5%, and IVF with ICSI is usually recommended instead.
Q: Is IVF more successful than IUI for PCOS?
A: Yes. Women with PCOS do reasonably well with IUI plus ovulation induction (15–20% per cycle), but IVF reaches 50–60% per cycle in this group and allows single embryo transfer, minimizing the multiples risk.
Q: How much does each percentage point of success cost?
A: For a woman under 35, one $850 IUI cycle buys a ~15% chance — about $57 per percentage point.
One $18,000 IVF cycle buys ~50% — about $360 per point. IVF costs more per point but delivers a far higher absolute probability, so cost-effectiveness depends on your age and diagnosis.
Q: What are mini-IVF success rates?
A: Mini (mild-stimulation) IVF uses much lower drug doses and reports 25–35% per-cycle success for women under 38 [3] — above IUI, below conventional IVF. It is the middle path for patients who want better odds than IUI without high-dose medication.
How to Decide: IUI vs IVF for Your Situation
The choice is never only about success rates — it is how those rates interact with your age, diagnosis, budget and emotional bandwidth:
- Under 35 with unexplained or mild male factor infertility: 3 IUI cycles are reasonable — a 30–40% cumulative pregnancy rate at manageable total cost.
- 38 or older: the data increasingly favors going straight to IVF, since IUI below 10% per cycle means 3–6 months lost from your best remaining fertile window.
- A clear structural diagnosis (blocked tubes, severe male factor, endometriosis): IUI adds nothing — go directly to IVF.
- Cost is the binding constraint: international destinations offer full IVF packages at $5,000–$12,000 per cycle — the price of 6–10 US IUIs.
Compare clinics’ success rates and pricing in our global fertility clinic directory, read the full IUI vs IVF comparison guide for cost, timeline and procedural differences, and see country-by-country IVF costs before you budget.
This article was written by the ProIVF Medical Editorial Team and reviewed by the ProIVF Medical Advisory Board. Last updated: July 14, 2026. It is for informational purposes only and does not constitute medical advice — IUI and IVF success rates vary with individual history, diagnosis, clinic quality and location. Consult a licensed fertility specialist and verify data directly with clinics before deciding. Questions? Contact us.
Sources
[1] American Society for Reproductive Medicine (ASRM) — patient education resources [2] Centers for Disease Control and Prevention (CDC) — ART success rates [3] Society for Assisted Reproductive Technology (SART) — clinic outcomes data [4] Human Fertilisation and Embryology Authority (HFEA) — UK IVF and IUI success rates
