Mirena Information

 Dr Shane Corr

Dr Miriam Clark

Information on Mirena Insertion

The inta Uterine System, known as Mirena, is commonly used, reversible,

contraceptive method that is also often used for its effect on reducing or stopping your

periods. It is a T -shaped device made of soft plastic, with a sleeve of a compound

similar to your normal hormone, progesterone, which is slowly released locally into

the lining of the womb following insertion through the cervix in the vagina. It lasts

for five years but can easily be removed in the meantime if required. After five years

it should be removed and another inserted. 

Mirena acts in three ways

1. The hormone thins the lining of the womb and this stops you getting pregnant.

It can also make periods lighter and shorter, and in most people they stop. This

is supposed to happen and your period will return if your Mirena is removed.

2. It thickness the mucous in the cervix to prevent sperm from entering the womb.

3. It stops sperm functioning in the womb.

It forms no role in emergency contraception .

The Mirena should ideally be inserted six weeks after having a baby even if periods

are not regular and provided there is no risk of pregnancy in the meantime.

Common problems experienced with Mirena in this practice:

Discomfort on insertion- short lived and help by paracetamol tablets.

Expulsion- Very rarely occurs but highest chance in the first twenty-four hours then

 inside seven days. Very slight risk of this happening at period time following this.

Contact the surgery if you are concerned.

Periods- First one after insertion can be heavier than normal but these ease off after

and majority will have stopped inside 9-12 months. Remainder of people usually have

lighter periods than before.

Infection- Can happen if you have had an infection in the womb, you should not proceed

 with the Mirena insertion. Every effort is made to insert the Mirena in a sterile

way and infection in this way is very rare. Mirena gives you no protection form

sexually transmitted disease (STD) and if you contract an infection, it may be

necessary to remove the Mirena coil. Contact the surgery if you experience pain,

fever or painful sex after insertion of the Mirena.

Pain- Problem if the Mirena is not in the correct position. Pain in the lower back

but again, is short lived. I have found that removal of Mirna in these cases often

shows it is not the case of the pain in the first place.

Perforation- Very rare problem with insertion but risk is there if you had

infection in the womb in the past, surgery to the womb itself or after having a baby,

Pregnancy- Pregnancy outside the  womb can still happen but are extremely rare. This

can happen with any method of contraception but risk with Mirena is less than no

contraception at all. It is important to check for the strings as a pregnancy can

occur if the device slips or is expelled. Mirena only works when it is in the position

in the womb and has no other contraception effects otherwise.

Mood Swings, weight gain and changes in greasiness of skin and hair are very rare and

unusual problems.

Other points about the Mirena:

Smears- are not affected by the Mirena and are as recommended every 3 years.

Medication- other medications do not affect the Mirena- however in certain illnesses

such as diabetes it may alter your blood sugars.

Vomiting & Diarrhoea- Doesn't affect its action and you can't forget to take it.

Contraception- It works, and is more reliable than any other method of

contraception. If 1000 sexually active women were using just Mirena for contraception

 for a year two might become pregnant in that year, compared with ten with the pill

and female sterilization five. Mirena starts working straight away following insertion,

but I suggest you use condoms for seven days to prevent infection. Also, tampons should be

avoided for seven days in case they catch the strings.

The Strings- These are important they are needed to remove the device, they help with

contraception and let us know the device is still there. Your partner should not notice the

strings during intercourse. It is recommended that you check them three months after

insertion and then every year. You can feel for the strings yourself and if you cannot find them

contact the surgery and we will arrange to see you.

The patient information leaflet that you will get should address any other queries you may have. Or

you can contact Dr Clark at the surgery.