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Hormonal Coils

Video courtesy of NHS Lothian.

Hormonal Intrauterine Contraception

What is hormonal intrauterine contraception (IUC)?

  • You may have heard of this called a ‘coil’.
  • It is a small “T” shaped device that is put into the womb, which slowly release the hormone progestogen. It has two thin threads on the end, which hang through the entrance of the womb (cervix) into the top of your vagina. These should not make sex uncomfortable for you or your partner. 
  • In the UK two types are available, which last for different durations of time:
    • Mirena® (5 years)
    • Jaydess® (3 years)

 How does it work?

  • It works by making the lining of your womb thinner so it is less likely to accept a fertilised egg.
  • It also thickens the mucus of your cervix and therefore it is more difficult for sperm to move through it and reach an egg.
    In some women it stops the ovaries releasing an egg. It does not cause abortion.

 How effective is it?

  • Contraceptive use can either be perfect (always correct) or typical (more accurate, as it’s sometimes difficult to use contraception correctly every time). 

  • With typical use of the IUS, approximately 2 in 1000 people become pregnant within the first year of use.

 How is it fitted?

  • You will need to talk to your GP or the doctor or nurse at the clinic to see if it is the right method of contraception for you. They will ask you about your family's medical history and any illness or operations you have had. For some reasons it may not be the best option for you.
  • Some GPs will fit IUC, but not all, so check that they offer this service before you go. If your GP does not fit IUC or you would prefer to you can come to a Sandyford Clinic.
  • The IUC is fitted inside the womb. The doctor or nurse will examine you internally to find the position and size of your womb before they put in an IUC.
  • Fitting an IUC takes about 10–15 minutes. It can be uncomfortable or painful for some women. Some women find local anaesthetic helpful. Your doctor or nurse will talk to you about this beforehand.
  • You will be having a procedure and some people may feel a little faint or unwell. We ask that if you need to bring children with you that someone is able to look after them. We are unable to provide any childcare.
  • Have a light meal before attending your appointment.Some people experience cramping after the procedure. It may be helpful to take some simple painkillers before attending.
  • If you feel unwell after it's fitted or if you think it has moved out of place (the doctor or nurse will show you how to check this) contact your GP or staff at a clinic immediately for advice.
  • The IUC is fitted inside the womb. The doctor or nurse will examine you internally to find the position and size of your womb before they put in an IUC.
  • Fitting an IUC takes about 10–15 minutes. It can be uncomfortable or painful for some women. Some women find local anaesthetic helpful. Your doctor or nurse will talk to you about this beforehand.

When can it be fitted?

To ensure we can safely fit your intrauterine contraception it is important that:

  • You avoid any unprotected sex after your last period.
  • This means using condoms consistently and correctly, or using another form of reliable hormonal contraception such as the combined pill, patch or ring, progestogen-only pill, injection or implant.
  • If you are not having regular periods you should use effective contraception or avoid sex for at least 3 weeks before having your IUC fitted.
  • If you are having your IUC replaced you should use contraception or avoid sex for one week before, in case there is any difficulty fitting the new IUC after the old one has been removed.

What are the advantages?

It is a highly effective method of contraception. 

  • It works for up to three to five years (depending on method chosen). 
  • It doesn't interfere with having sex in any way.
  • Your period usually becomes much lighter, shorter and sometimes less painful. They may stop completely after the first year of use. 
  • It can be very useful if you have heavy painful periods. 
  • It can be used if you are breastfeeding. 
  • You can use it if you cannot use oestrogens (hormones) like those found in the combined pill
  • Your normal levels of fertility return quickly after IUC is removed. 
  • Mirena® can also be used as a progestogen component of hormone replacement therapy.

Are there any disadvantages?

Your periods may be irregular and more painful. Although this often improves after a couple of months. 

  • A very small number of women get an infection during the first 20 days after getting IUC. A doctor or nurse may advise you get checked for any possibly existing infections before IUC is fitted. 
  • IUC can sometimes fall out (about 1 in 20). This could happen just after it is inserted or with a heavy period. Your doctor or nurse will show you how to check your IUC threads every month to make sure it is still in place. 
  • Very occasionally the IUC may go through your womb or cervix (about 2 in 1000). This may cause pain but often you will not realise it has happened. If this occurs the IUC may have to be removed by surgery. 
  • If you do become pregnant while you are using IUC there is an increased risk of the pregnancy being an ectopic pregnancy. This risk of ectopic pregnancy is less in women using IUC than in women using no contraception. 
  • Some women experience hormone side-effects such as headaches, acne and breast tenderness. 
  • Some women may develop cysts on their ovaries. These are not dangerous and do not usually need to be treated. Some women may experience pelvic pain. The cysts usually go away without treatment. 
  • IUC protects you from pregnancy but not sexually transmitted infections.

Only condoms can provide protection against most infections

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