Contraceptive Implants And Injections

Monday 1st February 2010

Contraceptive implants and injections are long-acting, effective methods of contraception. They are over 99% reliable in preventing pregnancy, which means that less than one in 100 women who use the implant or injection will become pregnant each year.

The implant and the injections work in the same way: by slowly releasing a hormone called progestogen into your body. They do not protect you against sexually transmitted infections (STIs).

They can be started at any time during your menstrual cycle, as long as you and your doctor are reasonably sure that you are not pregnant.

Implants

There is currently one type of contraceptive implant used in the UK called Implanon.

Implanon is a small (4cm), thin flexible tube. It is implanted under the skin of your upper arm by a doctor or nurse, using a local anaesthetic to numb the area. The small wound made in your arm is closed with a dressing and does not need stitches.

Implanon works for up to three years before it needs to be replaced. You can continue to use it until you reach the menopause.

The implant can be removed at any time by a specially trained doctor or nurse. It takes a few minutes to remove, using a local anaesthetic.

As soon as the implant is removed, you will no longer be protected against pregnancy. If you want to use a different method of contraception after the implant, you will need to start this seven days before the implant is removed. This is because sperm can survive in the womb for up to seven days after sex.

Injections

The contraceptive injection is usually given into a muscle in your bottom, but sometimes into a muscle in your upper arm. There are two types available:

• Depo-Provera is the most commonly used injection in the UK and is effective for up to 12 weeks, after which another injection is given.
• Noristerat is effective for up to eight weeks.

Where to get them

You can get an injection or implant at your GP surgery or a genito-urinary (GUM), contraception or sexual health clinic. It will be given to you by a specially trained doctor or nurse.

Who can use them

Most women can be fitted with the contraceptive implant or given the contraceptive injection. They may not be suitable for you if you:

• think you might already be pregnant,
• want your periods to remain regular,
• have bleeding in between periods or after sex,
• have arterial disease or a history of heart disease or stroke,
• have a blood clot in a blood vessel,
• have liver disease,
• have migraines, or
• have (or have had) breast cancer.

How Do Contraceptive Implants And Injections Work?

Contraceptive implants and injections steadily release the hormone progestogen into your bloodstream.

Progestogen is very similar to the natural hormone progesterone, which is released by a woman's ovaries during part of the menstrual cycle.

The continuous release of progestogen:

• stops you from releasing an egg every month (ovulation),
• thickens the mucus from the cervix, making it difficult for sperm to pass through to the womb and reach an unfertilised egg, and
• makes the lining of the womb thinner, so it is unable to support a fertilised egg.

This information was taken from the NHS direct website where you can find out more about the pros and cons of using contraceptive implants and injections.