Intrauterine insemination (IUI) places specially prepared sperm directly inside the womb around the time of ovulation. It is simpler and less invasive than IVF, and the insemination itself takes only a few minutes. This page explains how it works and what to expect.
What it is
In IUI, a thin, soft plastic tube (catheter) is passed through the cervix to place washed sperm high inside the womb. This puts more healthy sperm closer to the egg when it is released from the ovary.
Why wash the sperm? Washing separates the best-quality sperm from slow, non-moving or abnormally shaped sperm and from the seminal fluid, leaving a small, concentrated sample that is suitable to place inside the womb.
| Feature | IUI | IVF |
|---|---|---|
| Where fertilisation happens | Inside the body | In the laboratory |
| Egg collection | Not needed | Needed, under sedation |
| Anaesthesia | None | Sedation or general anaesthetic for collection |
| Open tube needed | Yes | No |
Who it's for
- Unexplained infertility
- Mild sperm problems, such as low count, or ejaculation difficulties
- Cervical mucus problems or a narrow cervix
- People using donor sperm, including single women and same-sex couples
- People who cannot have vaginal intercourse
Because it takes 20 minutes or less and tends to cost less than other options, IUI is often the first treatment tried when the tubes are open and problems are mild. It can be done with a partner's sperm or donor sperm.
IUI is not likely to work for severe problems such as blocked tubes or very low egg reserve. IVF may be advised instead.
- Problems with cervical mucus that make it hard for sperm to reach the uterus.
- Low sperm count or problems with ejaculation.
- An allergy to semen.
- Unexplained infertility, or treatment using donor sperm.
Step by step
- Tests firstUsually a pelvic exam, ultrasound, semen analysis, infection screening, blood tests and a check that the tubes are open.
- Natural or stimulated cycleIUI can follow your natural cycle, or use fertility medicine: tablets for about five days or injections for up to two weeks.
- Tracking ovulationOvulation is tracked with home LH kits, blood tests or transvaginal ultrasound. Sometimes an hCG trigger injection is given.
- Sperm washingOn the day, a fresh sample (or thawed frozen sample) is washed in the lab to concentrate healthy, moving sperm.
- InseminationUsually 24–36 hours after the LH surge or trigger, a speculum is placed and the catheter passes through the cervix to release the sperm.
- Pregnancy testA pregnancy test can be taken about two weeks after IUI. Progesterone is sometimes prescribed in between.
| Stage | Typical timing |
|---|---|
| Whole IUI cycle | About four weeks from start to finish |
| LH surge detected to insemination | Within 24 to 36 hours |
| Placing the sperm | A few minutes |
| Rest afterwards | 10 to 30 minutes, if advised |
| Insemination to pregnancy test | About two weeks |
Ovulation timing can be tracked with home ovulation kits, blood tests or ultrasound. On the day, the semen sample is "washed" in the lab to concentrate the healthiest sperm before it is placed in the uterus through a thin catheter.
What it feels like
No anaesthesia is needed. The insemination feels similar to a smear test and takes just a few minutes. You may be asked to lie down for 10–30 minutes afterwards.
Mild cramping and light spotting for one or two days are common. Most people go back to normal activities the same day.
You can ask the clinic what the catheter and speculum will feel like before you start. Breathing slowly and relaxing the pelvic muscles can make the speculum more comfortable.
Most people feel only mild discomfort while the catheter is placed. Afterwards, mild cramping and light spotting for one or two days are common, and most people return to normal activities straight away.
How to prepare
- Complete the tube check and semen analysis before your first cycle
- Follow the clinic's instructions on timing exactly
- Ask your partner about the sample instructions in advance
- Tell the clinic about any medicines you take
- Don't miss monitoring scans in a stimulated cycle
- Don't expect success in the first cycle; several may be needed
- Don't ignore fever or severe pain afterwards
Cleveland Clinic notes most IUI pregnancies happen within the first three to four cycles.
Risks and side effects
| Risk | What to know |
|---|---|
| Multiple pregnancy | The main risk; higher with fertility drugs. Scans help limit it. |
| OHSS | Possible when ovaries over-respond to fertility drugs |
| Infection | Rare |
| Cramping or spotting | Mild and short-lived |
Monitoring scans in a stimulated cycle let the doctor see how many follicles are growing, which helps reduce the chance of a multiple pregnancy. Ask in advance what the plan is if too many follicles develop.
- Multiple pregnancy: more likely when fertility medicines are used to stimulate the ovaries.
- Ovarian hyperstimulation syndrome (OHSS): a reaction to too much stimulation medicine.
- Infection: rare.
Many providers suggest trying about three IUI cycles before moving on to IVF, but the right number depends on your age and the cause of infertility.
How DBN does it
- IUI takes about 2–3 weeks per cycle, with no anaesthesia
- Approximate price: 15,000–30,000 THB
- The first consultation is free; prices are confirmed at consultation
When to see a doctor
- You have been trying to conceive without success and want to know if IUI suits you
- You plan to use donor sperm
- Semen analysis showed a mild problem
- You have fever, heavy bleeding or strong pain after IUI
Questions & answers
Does IUI hurt?
It is usually close to pain-free and takes a few minutes. Some people have mild cramps.
Can frozen sperm be used?
Yes. Frozen partner or donor sperm can be thawed and washed before insemination.
How does IUI compare with IVF?
IUI is simpler and less invasive, but HFEA says its success rates are generally around a third of IVF's.
Related DBN services
Related articles
Sources
- Intrauterine insemination (IUI) — HFEA
- IUI (Intrauterine Insemination): Procedure & Results — Cleveland Clinic
- Infertility: Treatment — NHS