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Coils (IUDs)

Many women choose coils as protection against pregnancy. After the development of the newest coil – the IUS – even more are expected to choose it. The coil is put in place by a general practitioner or at a birth control clinic.

How does it work?

The effect of the copper coil relies on several conditions:

  • The sperm is destroyed so they have trouble reaching the egg
  • Those sperm that reaches the egg have difficulty fertilising it and
  • If an egg becomes fertilised it cannot attach to the mucous membrane of the uterus

The IUS works in the same way as the copper coil but has also an inhibiting effect on ovulation.


The degree of safety is the same as contraceptive pills. There is a 98% chance that you do not become pregnant over the course of 12 months.

A coil may fall out and you should therefore regularly check whether you can feel the string in the vagina. The risk of the coil falling out is greatest within the first months after it has been put in place. If you are not certain whether you can feel the string, you should contact the doctor. Most coils work for 4-6 years, a few up to 10 years.


  • Usually it is only women who have been pregnant who can use a coil
  • Powerful and more painful menstruations are often seen when using a copper coil. Around 10% of all women with a copper coil want it removed for that reason after a couple of months use. For the same reason, it is not advisable that women with powerful and/or painful menstruations use a copper coil
  • When using a IUS, passing spotting may appear together with headache, tightness across the chest and mood swings
  • It does not protect from sexually transmitted diseases


  • High degree of safety
  • The coil takes effect right away
  • The coil works for 4-10 years
  • An IUS does cause more powerful and more painful menstruations and are therefore particularly suitable for women with powerful and painful menstruations.

Putting the coil in place

A copper coil is also effective if the coil is put in place within 5 days after the unprotected intercourse. The degree of safety is higher than the use of the morning-after pill and it has the advantage that henceforward you have good protection against pregnancy. It is recommended that you take a pregnancy test 3-4 weeks after the coil has been put in place.

Further reading on Sterilisation