The choices Intrauterine system (IUS)

Intrauterine system (IUS)

What is it?

The IUS is a long term method of contraception that contains progestogen. It is a small “T” shaped device made from plastic that is inserted into the womb. The IUS is fitted by a doctor or nurse and is left in the womb for up to five years. It has two soft threads at one end that hang through the opening at the entrance of your womb (cervix) into the top of your vagina. It is normally fitted during the first seven days of your period. If fitted at any other time, an additional method of protection must also be used for seven days.

Once fitted the IUS should be checked by your doctor or nurse six weeks after insertion. If you have any problems you can go back any time.

How does it work?

The IUS works by:

• Thickening the mucus of the cervix to act as a barrier to sperm
• Stopping a fertilised egg settling by keeping the lining of the womb thin
• Sometimes stop ovaries releasing an egg

How effective is it?

The IUS is over 99% effective.

What are the benefits?

• You do not have to remember to take a pill every day
• You are protected against pregnancy for up to five years
• Doesn't interrupt sex
• Can be used by breastfeeding women
• An ideal method if taking estrogen is not an option
• Hormones do not have to go through the stomach so protection is not affected by sickness or diarrhoea
• Your periods usually become much lighter and shorter, and sometimes less painful. They may stop completely after the first year of use
• Fertility returns quickly when removed

Who may not be able to / may not want to use it?

Women who:

• Have had cancer of the womb or ovary
• Have breast cancer or have had it in the last five years
• Have active liver disease
• Have unexplained bleeding from the vagina
• Have an untreated sexually transmitted infection or pelvic infection
• Have had problems with their womb or cervix
• Suffer from migraines with aura
• Certain types of heart and blood vessel diseases

Possible side-effects?

Not all women will experience side-effects

• Breast tenderness, acne, headaches
• Small chance of infection after 20 days as a result of insertion
• During those first few months, you're likely to have irregular (but fairly slight) bleeding
• There is a risk that the IUS might go through (perforate) your womb or cervix when it is put in. This is rare when fitted by an experienced doctor or nurse. This may cause pain, but often there are no symptoms. If this happens the IUS will have to be removed by surgery
• The IUS can be pushed out of your womb (expulsion) or it can move. This is why your doctor or nurse advises you to check the threads every month
• Increase in the risk of developing ovarian cysts

What if:

I want to become pregnant?

A trained doctor or nurse can remove the IUS at any time. Ideally you should wait for one period before trying to get pregnant. Waiting means the pregnancy can be dated more accurately and you can start pre-pregnancy care, such as taking folic acid and stopping smoking.

Remember: Contact your doctor or nurse if you have any concerns or are worried / unsure about anything to do with your contraception.