Intrauterine Insemination (IUI) – Costs, Procedure & Success Rates

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written by Zappelphilipp Marx•27 May 2025
Photo: Catheter positioning washed sperm during an IUI treatment

Intrauterine insemination (IUI) is a minimally invasive and cost-effective form of assisted reproduction. Here, you’ll find out how the procedure works, what requirements are essential, what costs you might incur, and which factors affect success rates.

What is intrauterine insemination (IUI)?

During IUI, washed—that is, highly concentrated—sperm are introduced directly into the uterus via a fine catheter. This bypasses the cervical mucus, allowing the sperm to reach the egg more quickly. The method can be performed using partner or donor sperm (homologous or heterologous).

Common indications for IUI

  • Slightly reduced sperm quality (count, motility).
  • Irregular or absent ovulation in women.
  • Cervical factor infertility (thick mucus, antisperm antibodies).
  • Unexplained infertility despite regular intercourse.
  • Single women or same-sex couples using donor sperm.
  • Immunological causes (antisperm antibodies) with otherwise normal semen analysis.

Requirements for a successful IUI

  • At least one patent fallopian tube (confirmed by HSG or HyCoSy).
  • Confirmed ovulation—naturally or medically induced.
  • Fertile sperm (> 5 million motile after preparation).
  • No acute infection in the genital tract.
  • Genetic screening for donor sperm to exclude hereditary conditions.

Step by step: How an IUI works

  1. Preliminary tests & counselling: cycle monitoring, semen analysis, blood tests and ultrasound checks.
  2. Mild ovarian stimulation: Clomiphene or low-dose gonadotropins to support 1–3 follicles.
  3. Ovulation trigger: hCG injection once the lead follicle reaches 17–20 mm.
  4. Sperm preparation: fresh or thawed sample is concentrated by swim-up or density gradient.
  5. Insemination: 24–36 hours after the hCG trigger, the sperm is injected into the uterus via catheter (procedure < 5 minutes, usually comfortable).
  6. Luteal support: vaginal progesterone to support the uterine lining.
  7. Pregnancy test: blood β-hCG check 14 days after insemination.

Advantages of IUI

  • Direct placement of sperm—avoidance of cervical mucus barriers.
  • Minimally invasive and no need for general anaesthetic.
  • Less expensive than IVF or ICSI.
  • Short treatment duration and fewer clinic visits.

Quick comparison of fertilisation methods

  • ICI / IVI – Intracervical insemination
    Semen is placed at the entrance to the cervix via syringe or cup. Suitable for mild fertility issues or donor sperm; lowest cost and maximum privacy.
  • IUI – Intrauterine insemination
    Washed sperm are delivered directly into the uterus via catheter. Ideal for moderate male factors, cervical issues or unexplained infertility; clinically straightforward and mid-range cost.
  • IVF – In vitro fertilisation
    Multiple stimulated eggs are fertilised in the lab with prepared sperm. Standard for blocked tubes, endometriosis or failed IUI; higher success rates and higher costs.
  • ICSI – Intracytoplasmic sperm injection
    A single sperm is microinjected into an egg. Precision solution for severe male infertility or surgically retrieved sperm; highest cost but best chance when sperm quality is very low.

Success prospects: What are the chances with IUI?

The success rate per cycle varies by age:

  • Under 35 years: 12–18 %.
  • 35–40 years: 8–12 %.
  • Over 40 years: around 5 % or less.

Three to six consecutive IUI cycles can raise cumulative success rates to around 30–45 % before considering a switch to IVF.

Tips for improving success

Optimise your lifestyle:

  • Maintain a healthy BMI, stop smoking, limit alcohol intake.
  • Manage stress through yoga, meditation or moderate exercise.

Sperm and cycle optimisation:

  • Abstain for 2–3 days before providing a semen sample.
  • Accurate cycle monitoring (ultrasound & LH tests) for optimal timing.
  • Use fertility-friendly lubricant during intercourse in the stimulation phase.

Risks & safety

Medication risks:

  • Ovarian hyperstimulation syndrome (OHSS) – rare with low-dose protocols.
  • Multiple pregnancy risk (5–10 %) if more than one follicle releases an egg.

Procedure-related risks:

  • Mild cramping or light bleeding after catheter insertion.
  • Rare uterine infections (reduced by aseptic technique).

Emotional impact: Repeated negative tests can be distressing—consider psychosocial support or counselling.

Costs & NHS funding

In the UK, private clinics typically charge between £800 and £2,000 per IUI cycle, depending on the services included. The NHS may fund up to three cycles for eligible couples under local Clinical Commissioning Group (CCG) guidelines and specific eligibility criteria (age, BMI, prior treatments). Private health insurance may also contribute—check your policy.

When to consider the next step?

  • Under 35 years: after three to four unsuccessful IUI cycles.
  • 35–40 years: after three cycles without success.
  • Over 40 years or significantly reduced sperm quality: consider IVF or ICSI early.

Your clinic will advise on the optimal timing for a treatment change or additional tests.

Scientific sources & guidelines

Conclusion

Intrauterine insemination offers couples, single women and same-sex couples a realistic chance of pregnancy with moderate cost and stress. With careful cycle monitoring, appropriate stimulation and professional support, IUI can be the key step towards parenthood before moving on to more invasive treatments such as IVF or ICSI.

Frequently asked questions (FAQ)

Depending on age and underlying factors: 12–18 % for women under 35, 8–12 % for those aged 35–40, and around 5 % or less for women over 40.
Three to six IUI cycles can raise cumulative success rates to approximately 30–45 %.

Under 35: up to six cycles;
35–40: three to four cycles;
over 40: consider switching to IVF or ICSI due to lower IUI success rates.

At least one patent fallopian tube, confirmed ovulation (natural or triggered), at least 5 million motile sperm after preparation, no acute genital infection, and a normal uterine ultrasound.

No. A natural cycle IUI is possible with regular ovulation, though mild stimulation (Clomiphene/Letrozole) can improve success by maturing one to three follicles.

Private clinics typically charge £800–£2,000 per cycle, depending on the package. The NHS may fund up to three cycles for eligible couples under local CCG guidelines. Private health insurance cover varies by policy.

Provide a fresh semen sample (or have a frozen sample thawed) → preparation (30–60 min) → catheter insertion (about 5 min, usually comfortable) → 10 min rest.

For most, the procedure is barely noticeable; some may feel a short cramp similar to a cervical screening test.

Washing removes prostaglandins, white blood cells and debris, reducing infection and cramp risk, and concentrates the most motile sperm.

With mild stimulation: about 5–10 %; in a natural cycle: under 2 %. Ultrasound monitoring helps limit multiple pregnancy risk.

It’s rare. Under low-dose stimulation with up to three follicles, the OHSS risk is under 1 %.

Yes. Donor sperm must be washed, quarantined and screened for HIV/STIs. In the UK, licensed sperm banks supply donors under HFEA regulations.

Optimal: 24–36 hours after an hCG trigger (or 12–24 hours after a natural LH surge). Many clinics schedule the procedure about a day and a half after a positive ovulation test.

After preparation, at least 5 million progressively motile sperm is ideal. Fewer than 1 million progressive motile sperm may require ICSI.

Common: hot flushes, mood swings, headaches. Rare: visual disturbances with Clomiphene—stop treatment immediately if they occur.

Theoretically yes: uterine contractions may aid sperm transport. Evidence is limited, but it’s harmless.

After three to six unsuccessful IUI cycles, if over 40 years old, or with severely reduced sperm quality. IVF offers higher success rates but at greater cost.

The NHS may fund up to three cycles for eligible couples under local CCG guidelines. Private insurance cover varies by policy.

The optimal abstinence period is typically two to four days; more than seven days can reduce motility, while less than one day may lower volume.

Mild cramps or spotting can occur and typically settle within 24 hours.

Try community forums such as RattleStork or BabyCentre UK, and support groups like Fertility Network UK.