Intra Uterine Insemination (IUI)

Intra uterine insemination — IUI — is usually the first fertility treatment a couple is offered. It is far simpler than IVF, it is done in a few minutes without anaesthesia, and for the right couple it is a reasonable place to start.

Intra uterine insemination is not right for everyone. This page explains what intra uterine insemination is, what has to be
true about your body before it has a realistic chance of working, what happens
in a cycle, and the point at which a different treatment makes more sense.

On this page

• What intra uterine insemination actually is
• Who IUI is usually suitable for
• What has to be true before IUI can work
• An IUI cycle, step by step
• Does it hurt, and what happens afterwards
• How many cycles of IUI are reasonable
• When IUI is not the right treatment
• Risks and side effects
• Common questions

What intra uterine insemination actually is

In natural conception, sperm has to travel through the cervix, across the
uterus and up into the fallopian tube to meet an egg. Most sperm never get that
far, because the cervix filters out a large part of the sample.

IUI shortens that journey. A semen sample is prepared in the laboratory — a
process usually called sperm washing — so that the seminal fluid is removed and
the motile sperm are concentrated into a small volume of culture medium. That
sample is passed through the cervix with a soft, fine catheter and released
directly into the uterine cavity, timed to sit within hours of ovulation.

So IUI does two things: it puts more moving sperm closer to the egg, and it
puts them there at the right moment. It does not fertilise the egg for you.
Fertilisation still has to happen inside the fallopian tube. That is the most
important difference between IUI and
IVF,
where fertilisation happens in the laboratory.

Who IUI is usually suitable for

• Unexplained infertility. Tests on both partners are normal
  and conception still has not happened.
• Mild male factor infertility. A slightly reduced sperm
  count or motility, where concentrating the sample can make a difference.
• Ovulation problems. Irregular or absent ovulation,
  including
  PCOS,
  where IUI is combined with medication to induce ovulation.
• Cervical factor. Where the cervix or cervical mucus is
  preventing sperm from getting through — IUI bypasses the cervix entirely.
• Mild endometriosis. Early-stage disease with open tubes.
• Sexual or ejaculatory difficulty, or the use of
  donor sperm.

What has to be true before IUI can work

There are three conditions. If any one of them is not met, IUI is unlikely to
help and you should not be put through it.

You need to ovulate, or be able to be made to ovulate

There has to be a mature egg released. If you ovulate naturally, the cycle is
tracked. If you do not, tablets or injections are used to induce ovulation
first. See
ovarian
stimulation.

At least one fallopian tube must be open

Fertilisation happens in the tube. If both tubes are blocked, IUI cannot work,
however good the sperm sample is. Tubal patency is confirmed beforehand with an
HSG
or a HyCoSy scan.

The sperm sample must be good enough after preparation

What matters is not the raw count on the report but the total motile count
left after washing. Many units use a post-wash total motile count of around five
million as a working minimum. Below that, IUI has little to offer and ICSI is
usually the more honest recommendation. This is judged from a
semen
analysis, repeated if the first result is borderline.

An IUI cycle, step by step

An IUI cycle follows your menstrual cycle, so it takes about two to three
weeks from the start of a period to the insemination itself.

Day 2 or 3 — baseline scan

A transvaginal scan early in the cycle checks that the ovaries are quiet and
that there is no cyst left over from the previous month.

Stimulation, or a natural cycle

Some IUI cycles are done without medication, tracking your own ovulation. More
often, mild stimulation is used — tablets such as letrozole or clomiphene
citrate, or low-dose injectable gonadotropins — to encourage one or two follicles
to mature. The aim is deliberately modest. Growing many follicles does not make
IUI safer or better; it raises the risk of a twin or triplet pregnancy.

Days 8 to 12 — follicle tracking

You come back for two or three short scans to watch the follicles grow and to
check the thickness of the uterine lining. The scans decide the timing; there is
no fixed calendar.

The trigger injection

When a follicle reaches maturity, an hCG trigger injection releases the egg at
a predictable time, and insemination is scheduled for the following day or so. In
an unmedicated cycle, a urine LH kit may be used instead to detect your own
surge.

The insemination

Your partner gives a sample on the morning of the procedure, usually after two
to three days without ejaculation, and the laboratory prepares it. You then lie
on an examination couch: a speculum is passed, the cervix is cleaned, and a fine,
soft catheter carries the prepared sperm into the uterus. There is no anaesthesia
and no cutting.

The wait

A progesterone supplement is often prescribed for the second half of the
cycle. A blood pregnancy test is done about two weeks after the insemination.
A urine test taken too early can be misleading, because the trigger injection
itself contains hCG.

Does it hurt, and what happens afterwards

Most women describe IUI as similar to a cervical smear — uncomfortable rather
than painful. Some cramping during or after the catheter is normal, as is light
spotting for a day.

You do not need bed rest. Lying flat for days afterwards has never been shown
to change anything. Go back to normal activity, work and walking. Avoid heavy
lifting and strenuous exercise if you have been stimulated, because enlarged
ovaries are more vulnerable.

Call the clinic if you develop fever, offensive vaginal discharge, severe
one-sided pain, or abdominal swelling with breathlessness.

How many cycles of IUI are reasonable

This is the question that matters most, and the one most often avoided.

IUI is a treatment with a ceiling. If it is going to work for a particular
couple, it usually does so within the first few attempts. Most international
guidance suggests reviewing the plan after about three cycles and rarely
continuing beyond six. Repeating the same cycle a seventh and eighth time is
more likely to cost you time than to change the outcome — and time is the one
variable in fertility that cannot be recovered.

A fair plan says in advance how many cycles you will try, and what happens if
they do not work.

When IUI is not the right treatment

IUI should not be offered when:

• both fallopian tubes are blocked or damaged;
• the post-wash motile sperm count is very low, or there is no sperm in the
  ejaculate;
• there is moderate or severe endometriosis with distorted pelvic anatomy;
• ovarian reserve is significantly reduced and age makes delay costly;
• several properly conducted IUI cycles have already failed.

In those situations IVF or ICSI is the appropriate treatment, and starting
with IUI simply delays it. At Jananam Fertility Centre both partners are
evaluated before any treatment is recommended, and the plan is built from what
the tests show.

If you would like your reports reviewed before deciding, bring previous scans,
hormone results and semen analyses to your first consultation.

Risks and side effects

IUI is a low-risk procedure, but not risk-free. The main risk is multiple
pregnancy, which is why stimulation is kept mild and why a cycle with too many
growing follicles should be cancelled rather than continued. Ovarian
hyperstimulation is uncommon at these doses but possible. Infection is rare, as
the catheter is sterile and single-use. Cramping and spotting are common and
short-lived, and the medication can cause hot flushes, mood changes, headaches
and bloating.

Common questions

How long does IUI take, and does it hurt?

The insemination itself takes a few minutes, though you should allow about two
hours at the clinic because the laboratory needs roughly an hour to prepare the
sample. Most women find it comparable to a cervical smear test, with some
cramping during and shortly after. No anaesthesia is needed.

Do I need bed rest after IUI?

No. Resting for ten or fifteen minutes on the couch is usual, and then you can
go home and carry on. Prolonged bed rest does not help, and for most women it
makes the wait harder rather than easier.

Can IUI be done without injections?

Yes. A natural-cycle IUI tracks your own ovulation without stimulation, and
mild oral tablets are an intermediate option. Which route suits you depends on
whether you are ovulating and how your ovaries have behaved before.

What is the difference between IUI and IVF?

In IUI, prepared sperm is placed in the uterus and fertilisation still has to
happen inside the fallopian tube. In
IVF,
eggs are collected and fertilised in the laboratory, and an embryo is transferred
back. IUI is simpler and less invasive; IVF can work where IUI cannot, such as
blocked tubes or severe male factor.

When should we stop trying IUI and move on?

Agree a limit before you start. Most guidance suggests reassessing after about
three cycles and rarely going past six. If the reason IUI is not working becomes
clear during treatment — poor response, a tube that turns out to be blocked, a
falling sperm count — the plan should change then, not after another three
attempts.

The UK regulator, the HFEA, publishes a patient-facing outline of the same procedure, and the NICE fertility guideline (CG156) sets out where intra uterine insemination is and is not indicated.

Written and medically reviewed by Dr. Vani Sundarapandian, MD, DGO, FRCOG
(UK) — founder and Medical Director, Jananam Fertility Centre, Chennai.