Intra-Uterine System

Sexual and Reproductive Health

What is IUS?
The IUS has a plastic T-shaped frame like the copper IUD, but with a steroid reservoir. The term IUS is used to distinguish the hormonal intrauterine contraceptive from copper-based intrauterine devices (IUDs). The IUS is used both as a method of contraception as well as a treatment for heavy periods, very painful periods, and endometriosis.

How does the IUS work?
The device is 32mm in length and 4.8mm in diameter. It is inserted through the cervical canal into the uterus, where it sits releasing the hormone 24 hrs a day for a recommended duration of use of between 3 to 5 years. The amount of synthetic hormone delivered by the IUS is only a fraction of the daily dose received through oral contraceptives, so the side effects should be fewer and less noticeable with the IUS than with oral methods. The IUS can only be fitted by a qualified medical practitioner. During the procedure, which only lasts a few minutes, the cervix is dilated and the IUS is fitted using an insertion device.
The IUS prevents pregnancy in several ways:

  • It suppresses the endometrium, making it unfavourable to implantation.
  • In some persons the IUS reduces ovarian function by preventing the release of an egg each month (ovulation).
  • It also causes the cervical mucus to thicken, making it impenetrable to sperm.


How effective is the IUS?
The IUS is from 98% to nearly 100% effective in preventing pregnancy. The IUS has a mean failure rate of less than 0.2 per 100 women years for up to 5 years.

When can I have an IUS fitted?
You can start any day of the menstrual cycle if the healthcare provider is sure that you are not pregnant.

How is it fitted?

  • Your medical practitioner will check your vagina to check your uterus and the size of your womb.
  • You may need a smear test, to check for existing infections (STIs).
  • The insertion of the IUS should not take more than 5 minutes.
  • The IUS is inserted through the cervix and into the uterus (the vagina is held open for entry).
  • You may feel period-like pains and cramps after insertion for a few days. You can also take painkillers if you need to.


How do I know that it is still in place?

  • An IUS has two thin threads that hang down away from your uterus, on top of your vagina.
  • You may be taught to feel those threads and check that they are in place.
  • If you think that the IUS is dislodged or not in place you may want to use more protection (such as condoms) against pregnancy during sex.


Can I get pregnant when I remove the IUS?
An IUS may be removed at any time if a person wants to become pregnant. An IUS is removed by a medical practitioner who visualises the IUS threads in the vagina and gently pulls out the IUS.

What are the advantages of the IUS?

  • Reduction in heavy and prolonged menstrual periods
  • Reduction in excessive menstrual pain
  • Infrequent or absent menstrual periods
  • High efficacy
  • Reversible
  • Does not interfere with sexual intercourse


What are the disadvantages of the IUS?

  • Total absence of menstrual periods
  • Irregular bleeding
  • Dilatation of cervix is required, which is uncomfortable, and for some women painful
  • Possible expulsion of the IUS
  • Perforation of the uterus, bowel, or bladder
  • Malposition of the IUS
  • Pregnancy causing expulsion, perforation, or malposition
  • Slightly increased risk of ectopic pregnancy if there is an IUS failure


What are the side-effects of the IUS?
You may experience the following side-effects:

  • Some persons may develop functional ovarian cysts
  • Breast tenderness
  • Acne
  • Headaches
  • Mood changes
  • Nausea
  • Irregular bleeding
  • Total absence of menstrual period
  • Skin problems


What are the risks of the IUS?
Most women can use the IUS, including those who are HIV positive. Your medical practitioner will provide guidance according to your medical history.

The IUS may not be suitable for you in case of:

  • Pregnancy
  • Undiagnosed genital tract bleeding
  • Heart valve replacement
  • Congenital or acquired uterine anomaly which distorts the fundal cavity
  • Suspected or confirmed uterine or cervical malignancy
  • Recent trophoblastic disease
  • Serious side-effects occurring on the COC which are not due to oestrogen
  • Present liver disease, liver adenoma or cancer
  • Present thrombophlebitis or thromboembolic disorder

Relative risks include:

  • Chronic systemic disease
  • Risk factors for arterial disease
  • Past or present severe arterial disease
  • Severe lipid abnormalities
  • Recurrent cholestatic jaundice
  • Sex steroid-dependent cancer, e.g. breast cancer
  • Functional ovarian cysts which have required hospitalisation
  • Previous ectopic pregnancy
  • Medicines which may interfere with intrauterine system efficacy (seek a pharmacist’s or doctor’s advice if taking other medications)

What to remember:

  • Your kind of IUS
  • When to have the IUS taken out


Can I bleed when I start the IUS?
Bleeding changes and cramps are common. Go to your medical practitioner if these changes are bothering you.

How do I know if I have an infection?

  • Pain in your lower abdomen
  • High temperature
  • Smelly discharge


Can I switch to another method of contraception?
Yes, you can change to another method of contraception whenever you wish. Speak to your medical practitioner to further discuss other reliable methods.

Can I have an IUS fitted after a miscarriage?
The IUS can be inserted immediately after a miscarriage.

I have just had a baby. When can I have an IUS fitted?
An IUS can be fitted after 4 to 6 weeks after giving birth. You will need an alternative contraceptive from 3 weeks after birth until the IUS is inserted. In certain circumstances an IUS can also be inserted 48 hours after birth.

It is safe to use an IUS when you are breastfeeding and it will not affect your milk supply.

How often should I go for a check-up?
Your medical practitioner will tell you when to come for your next appointment. However, do not wait for the next appointment if:

  • You have missed a menstrual period, or think you may be pregnant
  • You think you could have an STI or HIV/AIDS
  • IUS strings seem to have changed length or are missing
  • You experience severe pain in lower abdomen


If I have the IUS, am I protected from Sexually Transmitted Infections?
No, only male and female condoms (when used correctly and consistently) protect you from STIs.