IUI vs IVF: Which Treatment Is Right for You?

You've been trying to conceive, and your doctor mentions fertility treatment. But should you start with IUI or go straight to IVF? It's one of the first big decisions you'll face — and the answer isn't always obvious.

IUI (intrauterine insemination) is simpler, cheaper, and less invasive. IVF (in vitro fertilization) is more complex, more expensive, and significantly more effective. Understanding when each option makes sense can save you time, money, and emotional energy.

IUI vs IVF: The Basics

The fundamental difference: IUI helps sperm reach the egg more efficiently but still relies on natural fertilization. IVF takes eggs and sperm out of the body, ensures fertilization happens, and transfers the resulting embryo back. IVF bypasses many potential problems that IUI cannot overcome.

Success Rate Comparison by Age

This is where the decision often becomes clear. The effectiveness gap between IUI and IVF is substantial — and widens with age.

At every age, IVF is significantly more effective per cycle. But IUI is also much cheaper — which is why many couples start there, hoping to avoid the cost and intensity of IVF.

Cost Comparison

IUI's appeal is largely financial. A single IUI cycle costs a fraction of IVF.

But Cost Per Success Tells a Different Story

When you factor in success rates, the cost comparison shifts dramatically.

Let's say you're 36 years old with unexplained infertility:

• IUI success rate: ~12% per cycle
• IVF success rate: ~40% per cycle

To achieve a 50% cumulative chance of pregnancy:

• IUI: Need ~5-6 cycles = $10,000-$20,000
• IVF: Need ~1-2 cycles = $15,000-$25,000 (or $3,500-$8,500 in Colombia)

The cost per live birth is often similar — and IVF gets you there faster. This is especially true for women 38+, where IUI success rates are so low that the cost per live birth becomes prohibitively high.

When IUI Makes Sense

IUI isn't always the wrong choice. It's reasonable to try IUI when:

Good Candidates for IUI

• Young age (under 35): Higher per-cycle success rates make IUI more worthwhile
• Unexplained infertility with normal testing: No obvious barriers that IUI can't overcome
• Mild male factor: Slightly low count or motility that's still above IUI thresholds
• Cervical factor: Sperm have trouble getting through cervical mucus
• Single women or same-sex couples using donor sperm: No male factor issues, just need sperm delivery
• Ovulation problems responding to medication: If the main issue is irregular ovulation and medication fixes it
• Limited budget for fertility treatment: When IVF truly isn't financially accessible

When to Skip IUI and Go Straight to IVF

In many situations, IUI is unlikely to work, and proceeding directly to IVF is more appropriate.

Skip IUI If:

The FASTT Trial: Evidence for Skipping to IVF

The landmark FASTT Trial compared different treatment pathways for unexplained infertility. The findings were striking:

This doesn't mean everyone should skip IUI — but it does mean the traditional "start low, go slow" approach isn't always optimal.

How Many IUI Cycles Should You Try?

If you're a good candidate for IUI, how long should you persist before moving to IVF?

The Evidence-Based Answer

• Cycle 1-3: Most IUI pregnancies occur here (88% of successes)
• Cycle 4: 95% of IUI successes have occurred by now
• Cycle 5-6: Diminishing returns — success rate per cycle drops significantly
• Beyond 6: Rarely recommended; suggests IUI isn't the right treatment for you

For most couples, 3-4 IUI cycles is a reasonable trial before moving to IVF. Continuing beyond this rarely leads to success and delays more effective treatment.

Factors That Might Justify More IUI Attempts

• Very young age (under 30) with excellent ovarian reserve
• Financial constraints that make IVF truly inaccessible
• Previous IUI pregnancies (shows it can work for you)
• Religious or personal objections to IVF

What Happens During Each Treatment

The IUI Process

1. Monitoring (Days 1-12): Ultrasounds and possibly blood tests track follicle development
2. Ovulation trigger: When follicles are mature, an hCG shot triggers ovulation
3. Sperm preparation: Partner or donor provides sample; lab "washes" it to concentrate motile sperm
4. Insemination: Doctor inserts thin catheter through cervix, deposits sperm in uterus (5 minutes)
5. Two-week wait: Normal activities resume; pregnancy test in ~14 days

The IVF Process

1. Stimulation (Days 1-10): Daily injections stimulate multiple egg development
2. Monitoring: Frequent ultrasounds and blood tests
3. Trigger shot: 36 hours before retrieval
4. Egg retrieval: Surgical procedure under sedation (15-30 minutes)
5. Fertilization: Eggs combined with sperm in lab; monitored for 5-6 days
6. Embryo transfer: Best embryo(s) placed in uterus (10 minutes)
7. Two-week wait: Progesterone support; pregnancy test in ~14 days

IUI and IVF in Colombia

Most international patients travel to Colombia specifically for IVF, where savings are substantial (50-70% less than US costs). IUI savings are more modest, and the treatment requires multiple monitoring visits that complicate travel logistics.

That said, some Colombian clinics offer IUI packages for patients who want to try it first or who are using donor sperm. If you're considering IUI abroad, expect 2-3 monitoring visits over about 10 days, plus the insemination itself.

Making Your Decision: A Framework

Start with IUI if:

• You're under 35
• Testing shows no blocked tubes, no severe male factor, reasonable ovarian reserve
• You're willing to try 3-4 cycles before IVF
• You want to start with the less invasive, less expensive option
• You're using donor sperm and have no other fertility issues

Go straight to IVF if:

• You're 38 or older
• You have blocked tubes, severe male factor, or very low ovarian reserve
• You need genetic testing of embryos
• Time is a critical factor
• The cost per live birth matters more than cost per cycle
• You've already done 3+ unsuccessful IUI cycles

Questions to Ask Your Doctor

1. "Based on my test results, what are my realistic chances with IUI vs IVF?"
2. "Are there any factors that make IUI unlikely to work for me?"
3. "How many IUI cycles would you recommend before moving to IVF?"
4. "What's my estimated cost per live birth with each approach?"
5. "Given my age, how much does the time factor matter?"

The Bottom Line

IUI and IVF aren't competing treatments — they're different tools for different situations. IUI is simpler and cheaper per cycle, but less effective. IVF is more intensive and expensive, but significantly more likely to work.

For young women with unexplained infertility and no other complications, 3-4 IUI cycles is a reasonable starting point. For women 38+ or anyone with known barriers that IUI can't overcome, proceeding directly to IVF often makes more sense — getting you to your goal faster without wasting precious time.

Discuss your specific situation with a fertility specialist. The right answer depends on your age, diagnosis, financial situation, and how you weigh time against money.

Read more: IVF Cost Guide | Understanding Fertility Tests | Preparing for IVF