IUI or IVF: Which Should You Try First?

IUI is usually tried first where the woman is under 35, ovulation is reliable, the fallopian tubes are open and any male factor is mild. It is simpler, cheaper and less invasive, with a lower chance per cycle. IVF is generally the better first option where there are blocked tubes, severe male factor, significant endometriosis, diminished ovarian reserve, or where the woman is in her late thirties or older and time matters. The usual approach is three to four IUI cycles before reassessing, but that only makes sense if you have the time to spend.

What is the difference between IUI and IVF?

	IUI	IVF
What happens	Prepared sperm placed directly into the uterus around ovulation	Eggs collected, fertilized in the laboratory, embryo transferred
Fertilization	Inside the body	In the laboratory
Medication	Minimal or none	Ovarian stimulation over roughly two weeks
Procedures	Brief clinic procedure, no sedation	Egg collection under anesthesia, then transfer
Cost	Substantially lower	Substantially higher
Chance per cycle	Lower	Higher

IUI requires open fallopian tubes and enough motile sperm, because fertilization still has to happen on its own inside the body. IVF does not, which is why it is the route where either of those is the problem.

When does IUI make sense first?

• Under 35, with reliable ovulation.
• Unexplained infertility.
• Mild male factor, where enough motile sperm remain after preparation.
• At least one open fallopian tube.
• Situations where intercourse is difficult or timing is the obstacle, and where donor sperm is used.

A study in Fertility and Sterility reported cumulative pregnancy rates of up to around 30 percent after three to four IUI cycles in this kind of group. Note that this is cumulative across several cycles, not a per-cycle figure, which is the distinction most often lost when IUI success rates are quoted.

When is IVF the better first step?

• Blocked or absent fallopian tubes, where IUI cannot work.
• Severe male factor, where ICSI is needed.
• Significant endometriosis.
• Diminished ovarian reserve, where time is the constraint.
• Where genetic testing of embryos is indicated because of a known genetic or chromosomal condition.
• Where several IUI cycles have already failed.

Research in Fertility and Sterility comparing the two in women aged 38 to 44 reported substantially more pregnancies with IVF than with IUI in that age group. Age is the reason: each IUI cycle takes a month, and in the late thirties and forties, months spent on a treatment with a lower chance per cycle carry a real cost.

How many IUI cycles before moving on?

Three to four is the usual point to reassess. Most of the cumulative success from IUI is achieved within those cycles, and the return on further attempts falls away.

Reassessment should be a real decision, not a formality. Signs that continuing is unlikely to help include irregular ovulation, poor follicle response, or a repeated pattern with nothing new learned. Ask your specialist directly what has changed across the cycles and what would need to change for a further attempt to be worthwhile.

How should cost enter the decision?

IUI is much cheaper per cycle, but four IUI cycles is not free, and if they do not succeed, that money and those months are gone before IVF starts. For a couple with time, starting with the simpler treatment is reasonable. For a couple without it, the cheaper route can end up being the more expensive one. Our costs page sets out pricing so you can compare the two properly.

We at Millennium IVF Clinic will go through which applies to your test results and your circumstances. You can arrange a consultation with our team.

Frequently asked questions

Is IUI painful?

It is generally described as similar to a cervical smear, brief and without sedation. Some cramping afterwards is common.

Can I go straight to IVF without trying IUI?

Yes, and in several situations it is the recommended course, including blocked tubes, severe male factor and diminished ovarian reserve. It is a discussion to have with your specialist rather than a fixed sequence everyone must follow.

Does IUI work with a low sperm count?

It depends how low. IUI needs enough motile sperm after preparation to fertilize on their own. Where the count or motility is very low, ICSI is generally the route. See our article on low sperm count.

What are the chances of twins?

IUI with ovarian stimulation carries a risk of multiple pregnancy if more than one follicle develops, which is why the response is monitored and a cycle is sometimes cancelled. Ask us how we manage this.