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Intrauterine Insemination (IUI) - A guide for patients

Intrauterine insemination (IUI) is a simple fertility treatment that places specially prepared sperm directly into the uterus around the time of ovulation.

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1

Why do we use IUI?

In natural conception, only a very small number of sperm reach the fallopian tube where fertilisation occurs. IUI helps by giving sperm a head start, increasing the number of sperm that reach the egg.

IUI may be recommended for: 

  • Unexplained infertility
  • Mild male-factor infertility
  • Mild endometriosis
  • Difficulties with sperm delivery through the cervix
  • Use of donor sperm
  • Situations where sperm has been frozen for future use

At Fertility Associates, IUI is often combined with fertility medications designed to help more than one egg mature during a treatment cycle.

2

Who might benefit from IUI?

IUI can be an effective first-line fertility treatment for people who:

  • Have been trying to conceive without success
  • Have mild reductions in sperm count or sperm movement
  • Have mild to moderate endometriosis
  • Require donor sperm
  • Need to use previously frozen sperm
  • Prefer a less invasive treatment before considering IVF

Your fertility specialist will discuss whether IUI is appropriate for your individual circumstances.

3

Types of IUI treatment

Natural Cycle IUI

Natural cycle IUI is performed without fertility medications.

  • This option may be suitable when:
  • Donor sperm is being used
  • Frozen sperm is being used
  • There are difficulties with sperm delivery through the cervix
  • Ovulation occurs regularly

Ovulation is carefully monitored, usually with blood tests or ovulation testing, to determine the best time for insemination.

Stimulated IUI

Stimulated IUI combines insemination with fertility medications that encourage the development of two or three eggs instead of one.

Medications may include:

  • Letrozole
  • Clomiphene citrate (Clomid)
  • Occasionally injectable fertility hormones

Monitoring involves:

  • Blood tests
  • Ultrasound scans
  • Ovulation tracking

By increasing the number of eggs available for fertilisation, stimulated IUI may improve the chance of pregnancy in selected patients.

4

What happens euring an IUI cycle?

Step 1: Start of your cycle

Contact Fertility Associates on Day 1 of your period (the first day you wake up with full menstrual bleeding).

Your team will provide instructions regarding:

  • Medications (if required)
  • Blood tests
  • Ultrasound scans
  • Timing of ovulation monitoring

Step 2: Monitoring

During your cycle, we monitor how your ovaries are responding.

Monitoring may include:

  • Hormone blood tests
  • Ultrasound scans
  • Ovulation testing

This allows us to determine the optimal time for insemination.

Step 3: Sperm preparation

On the day of treatment:

Partner Sperm

A semen sample is provided and prepared in our laboratory.

Donor Sperm

Frozen donor sperm is thawed and prepared by our embryology team.

The preparation process removes seminal fluid and concentrates the healthiest moving sperm for insemination.

Step 4: The insemination procedure

The prepared sperm is placed directly into the uterus using a very fine catheter.

The procedure:

  • Takes only a few minutes
  • Is similar to having a cervical smear
  • Does not require anaesthesia
  • Is generally painless

You are welcome to have a support person with you.

Step 5: After insemination

Most people can:

  • Return to work
  • Exercise normally
  • Continue normal daily activities
  • Have sexual intercourse if they wish

Some patients may be prescribed progesterone support after insemination.

5

IUI success rates

The chance of pregnancy depends on several factors, particularly age and the underlying cause of infertility.

Success rates are generally highest:

  • In younger women
  • When donor sperm is used
  • During the first few treatment cycles

Because pregnancy rates accumulate over time, several cycles may be recommended.

If pregnancy has not occurred after three to four IUI cycles, IVF is often recommended as the next step. Women aged 40 and over may be advised to move to IVF earlier.

6

Risks of IUI

IUI is considered a safe treatment, but as with all medical procedures there are some risks.

Multiple pregnancy

When fertility medications are used, more than one egg may ovulate.

Approximate risks include:

  • Twins: around 10% of pregnancies following clomiphene-stimulated IUI
  • Triplets: around 1%

The risk of twins appears lower with letrozole. Multiple pregnancies carry higher health risks for both mother and babies.

Ectopic pregnancy

An ectopic pregnancy occurs when an embryo implants outside the uterus, most commonly in a fallopian tube.

Although IUI is not thought to increase the risk, all fertility patients should be aware of the possibility. Early monitoring helps identify ectopic pregnancies as soon as possible.

Infection

Infection following insemination is rare, occurring in approximately 0.3% of treatment cycles.

Most infections respond well to antibiotics.

Bleeding

Some patients experience light spotting or bleeding from the cervix after the procedure.

This is usually minor and unlikely to affect the chance of pregnancy.

Rare reactions

Occasionally, patients may experience:

  • Dizziness
  • Fainting
  • A temporary drop in blood pressure during the procedure

This is known as a vasovagal reaction and is usually short-lived.

When you should contact the clinic

Please contact Fertility Associates if you experience:

  • Significant abdominal pain
  • Abdominal swelling or bloating
  • Nausea or vomiting
  • Difficulty breathing
  • Reduced urine output
  • Severe headache
  • Heavy bleeding
  • Fever or feeling unwell

Prompt assessment helps ensure any complications are managed early.

7

Frequently asked questions

Is IUI painful?

Most patients describe IUI as similar to a cervical smear. It is generally quick and well tolerated.

Do I need time off work?

No. Most people return to normal activities immediately afterwards.

Can I have sex after IUI?

Yes. Sexual activity can continue as normal unless your healthcare team advises otherwise.

How many IUI cycles should I try?

For most patients, three to four cycles are recommended before considering IVF.

Are the medications safe?

The medications used in IUI have been used for decades and have not been shown to increase the risk of birth defects, breast cancer, or ovarian cancer.

8

Why choose Fertility Associates?

Fertility Associates has been helping New Zealanders build families for decades, offering:

  • Specialist fertility doctors
  • Experienced fertility nurses
  • Expert embryology laboratories
  • Donor sperm programmes
  • Personalised treatment plans
  • Access to counselling and emotional support

We are committed to providing compassionate, evidence-based fertility care every step of the way.

Ready to Take the Next Step?

If you'd like to learn whether IUI is right for you, talk to the team at Fertility Associates about your fertility options and personalised treatment plan. You can:

This information is intended as a general guide and does not replace individual medical advice from your fertility specialist.

Ready to start your fertility journey?

Book a free 20 minute phone consultation with one of our expert fertility nurses.

Book now

The Biological Clock

This tool indicates:

  • Natural conception per month if you have no fertility issues
  • IVF success rate at the same age
  • When to seek help after months of unsuccessful attempts

If you are concerned at any stage – we recommend booking a doctor appointment or a free nurse consultation. The sooner you make a plan the better your chances in the long term.

When to seek advice early

  • If you have polycystic ovaries, endometriosis, or have been through a cancer diagnosis; we recommend you get in touch quickly so we can talk you through all your options and give you the greatest possible chance of success.
  • If you’re a single woman considering motherhood in the future; it’s best to approach us early and consider egg freezing as this can be an option for you while you have a higher ovarian reserve and healthier eggs.
Set your age and the months you’ve been trying to conceive
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Your chance of having a baby per month for fertile couples
Your chance of having a baby per IVF cycle (if experiencing infertility)

Body Mass Index calculator

Being overweight or underweight can reduce fertility, so it is important to keep your body weight within the normal healthy range.

Body Mass Index (BMI) is an indication of your body weight and can be calculated by dividing weight by height. You should aim for a BMI of between 20 and 25, as this will optimise your chances of conception.

Woman’s BMI below 19

Even in these modern times, nature knows best. If a woman's BMI falls below 19, the body senses famine and ovulation is switched off to prevent the risk of having a baby with malnutrition. Excessive exercise can reduce body fat and increase muscle mass to a point where periods cease for the same reason. Risk of miscarriage is also increased in women with a low BMI.

Being underweight

If a woman's BMI falls below 19, the body senses famine and ovulation is switched off to prevent the risk of having a baby with malnutrition. Excessive exercise can reduce body fat and increase muscle mass to a point where periods cease for the same reason. Risk of miscarriage is also increased in women with a low BMI.

BMI’s greater than 30

This can reduce fertility by 50%. Pregnancy for women with a 30+ BMI is often associated with problems such as maternal diabetes, high blood pressure, big babies and increased risk of caesarean section.

Add your height and weight to calculate your BMI