What is a Mirena?

A Mirena is a hormonal IUD. It is long-acting, reversible, and one of the most effective methods of preventing pregnancy. A Mirena IUD is a fit and forget method of contraception. Once it’s in there you don’t have to worry about it or think about contraception for up to five years.

The device is a tiny ‘T shaped’ piece of flexible tube that is put into your uterus. When we say tiny we mean it - 32mm! You won’t be able to feel it in there.

A Mirena contains a tiny amount of hormones that are released slowly into your uterus over the time that it is in there.

How does the Mirena work?

A Mirena works by making it difficult for the sperm to swim and get to the egg. A tiny amount of  hormones that are released from the device into your uterus creating a sticky mucus. The mucus acts like a barrier to stop the sperm from swimming through the opening of your uterus (the tunnel to get to the egg). If the sperm can’t reach the egg then you can’t get pregnant.

The Mirena also changes the environment inside your uterus. The inside of your uterus is like a nest for the egg. So if a sperm happens to get through the mucus barrier and reach an egg, they won’t be able to find a nest to settle in. The egg needs a safe nest to develop into a pregnancy. No nest, no pregnancy.

Getting an IUD

How is an IUD fitted?

Getting a Mirena is simple. The process is similar to having a smear test. A speculum is gently inserted into your vagina. The arms of the IUD are folded upwards as it goes through the opening of your uterus, kind of like a stick. Once the IUD is inside your uterus the inserting device is released and the arms fold downwards to create the ‘T’ liked shape. And just like that your IUD is fitted and you don’t have to think about it for up to five years.

Interesting fact: The arms of the device only open as wide as your uterus. The strings of your IUD are cut so that they are only a few cm long. The strings curl up inside your vagina, so you don’t have to worry about them hanging out.

All up, your appointment should take no longer than 15 minutes, with the insertion only taking a few minutes.

What will I feel?

Prior to arriving at your appointment, it is a great idea to take some ibuprofen and/or paracetamol to ease any discomfort you may feel during or after the IUD has been fitted.

The moment the Mirena is inserted you may feel a strong sharp period like cramp. This is the device going through the opening of your uterus and arms of the device opening. During these few seconds, take a deep breath in and a long breath out. Within minutes the discomfort should settle.

Once your IUD has been fitted you may feel a little crampy for the rest of the day – just like period cramps. You can continue about your normal day, or use it as an excuse to take some time for yourself, curl up on the couch with your favourite book or binge watch Netflix.

For the next couple of days you may have mild cramps and light spotting as the IUD settles into place. This is normal. Within a few days you won’t even realise that the Mirena is there.

Hormones in the Mirena

The Mirena contains a very small about of progestogen which is a synthetic version of the hormone progesterone, that your body makes naturally. Progestogen works by preventing ovulation (when your ovaries release an egg) and changing your cervical mucus to make it harder for sperm to reach an egg.

Out of all the types of hormonal contraception, the Mirena contains the least amout of hormones. The hormone is slowly released from the device over the time it is fitted and won’t linger in your body once it has been removed.

What happens to my period with a Mirena?

A Mirena may change your period. It might become lighter, shorter, and in some cases completely stop. This is normal.

The hormone released from your IUD changes the environment inside your uterus. Instead of the lining of your uterus thickening once a month to form a cosy nest for the egg, it remains thin. This stops the egg from being able to develop if fertilised; no nest, no pregnancy. Because the lining of your uterus doesn’t thicken there isn’t as much to come out as ‘blood’ during your period.

Also, as the lining of your uterus doesn’t thicken as much, your uterus doesn’t have to squeeze as hard to remove it. Therefore less cramps.

Even though the amount you bleed may change, you will still go through your monthly hormonal cycle. Unfortunately, the Mirena won’t stop your other normal period symptoms such as, tender breasts, mood swings, tiredness, changes in your skin, cravings, and eating too much chocolate.

If you normally experience heavy and crampy periods, a Mirena could make a real difference to your time of the month.

You can still use tampons or a moon cup if you have a Mirena as it is placed further up than where these will sit. They won’t interfere with your IUD, or get in the way of the strings.

When can I have sex?

You can have sex as soon as you feel ready after getting your Mirena IUD fitted. The Mirena protects you from getting pregnant from the moment it is put in.

A Mirena is an amazing form of contraception, but keep in mind, it doesn’t protect you from STIs. Condoms are the only contraception that also stop STIs.

Will the Mirena IUD make sex painful?

Sex should be the same. Your Mirena shouldn't cause you to experience pain and your partner shouldn't be able to feel it or the strings. If you experience any pain during sex because of your Mirena, please call us.

Checking on your Mirena IUD

Your Mirena has two thin nylon-like strings attached to it and they provide an easy way for you to check that your IUD is in place. If you are worried your IUD may have come out, you can always have a feel for the strings. Keep in mind the strings can be buried quite deep. If you try using a mirror, you won’t be able to see them.

Getting your Mirena IUD removed

When you no longer want your Mirena IUD, it can easily be removed. The strings on your Mirena IUD are there for the same purpose as a string on a tampon, but as tempting as it may be to pull the strings, it is best left to one of our nurses or doctors.

The process is even easier than getting your IUD fitted. A speculum is gently inserted into your vagina, the strings are pulled, and then your Mirena IUD is out. When the strings are pulled, the arms of the Mirena IUD fold up and the device once again becomes like a stick so that it can easily pass through the opening of your uterus and be removed.

The removal only takes a few minutes; all up, your appointment should take no longer than 15 minutes.

Once your Mirena IUD has been removed your fertility returns to normal. You will be able to get pregnant straight away.

What happens once my Mirena IUD is removed?

Once your Mirena IUD is removed, your body and uterus will return to normal almost immediately.

Your next period will depend on where you are in your cycle when the device is removed, but should be within four weeks. Your first period may be lighter than normal, as the lining of your uterus may not have had time to fully thicken. By your second or third period, you will be back to what it used to be.

Does a Mirena IUD affect my fertility?

A Mirena IUD does not affect your fertility or chances of getting pregnant once it is removed.

Replacing your IUD

Your Mirena is effective against pregnancy for up to five years. If you get to the end of its life, and you love it so much that you want another one, it can be replaced. We swap the old one for a new one. It can all be done within a 15 minute appointment.

Since you are replacing like for like, your body will adjust to the new device much faster than when you got your first Mirena fitted. It is safe to use a Mirena IUD for as long as you like. We will send you a reminder four weeks before your device is due to be changed.

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The Jab

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Other contraception

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Interested in using contraception?

Reach out online or call 0800 226 784 to speak to one of our nurses. We value your decision about your health.

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