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Michael East

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MIRENA IUCD (for management of heavy periods)

The Mirena IUCD is an intra uterine device which contains a small dose of progesterone hormone.

It can be inserted in the rooms or may require a light general anaesthetic depending on the age of the woman, the number of children she has had, and also the clinical circumstances.

The Mirena IUCD is used in the management of heavy periods.

It is ideal for:

1.  Women with symptoms of endometriosis who also have heavy periods.

2.  Women with heavy, regular periods with a relatively normal size uterus

3.  The Mirena IUCD is a very effective contraceptive

If there are concerns regarding the nature of the heavy periods or if there is irregular vaginal bleeding, a Hysteroscopy (inserting a telescope into the uterus) may be combined with insertion of the Mirena IUCD.  This is a day case procedure.

Following Mirena IUCD insertion:

    • There is a small risk of infection in the first week to 10 days
    • There may be uterine cramps in the first few weeks
    • Periods are often irregular for the first 3-4 months
    • After 3-4 months the periods become lighter and on occasion stop altogether

The Mirena IUCD can stay in place for up to 5 years before needing to be removed and/or changed.

Approximately 80% of women who have a Mirena IUCD find it very satisfactory.

20% of women who have a Mirena IUCD have it removed because of irregular bleeding, pain or side effects related to the progesterone such as fluid retention, acne or exacerbation of premenstrual symptoms.

The Mirena IUCD is not as effective in women who have an enlarged uterus due to fibroids, and in women who have a significant pain component associated with their heavy periods.



Some women have had bad experiences with Mirena IUCDs, however, as a clinician who inserts a lot of Mirena intra uterine devices, I would like to share with you how it can help many women and also to point out how to recognise if it is not suiting you. Usually in my experience it is generally part of the solution and not part of the problem.

Firstly let us consider what a Mirena consists of:

It is a 'T-shaped' plastic (nylon) device that has a slow release hormone capsule attached to the 'stalk' of the T. It acts as a very efficient contraceptive and has a 5 year lifespan.

What are its properties?

The 'T' serves to hold the hormone capsule inside the cavity of the uterus. It is chemically inert but as a foreign body it can act as an irritant to the uterus causing the uterine muscle to contract and cramp more often. This is more likely to occur in teenagers as the uterus is smaller and the 'fit' a little tighter. For the younger woman the smaller Jaydess may be a better choice. The hormone is a copy of the female hormone progesterone, and has two main actions:

  1. It causes relaxtion of the uterine muscle (called smooth muscle) and as such, trends to decrease the irritant effect of the plastic 'T'.
  2. It inhibits the growth of the uterine lining (endometrium) and any simmilar tissue (endometriosis and adenomyosis). This inhibition tends to reduce pain.

Generally, the hormone effect tends to dominate over the foreign body effect, and if that is so, then a Mirena tends to produce benefit to the user. If the foreign body effect is dominant, then cramps and bleeding can aggravate endometriosis symptoms.

The amount of hormone that leaks into the rest of a woman's body is equivalent to taking one progesterone only contraceptive pill per week. As a result most women do not experience hormone related side effects. Some women however are sensitive to this small hormone leak and experience a deterioration of acne or a flatness of mood. Some women find that their cyclical mood swings get worse, while others notice no difference or improvement.

Who do I advise to have a Mirena placed?

Most women undergoing surgery for endometriosis in my experience, benefit from having a Mirena placed at the time of surgery while they are asleep. They should be warned that it takes at least three months to 'settle in' and breakthrough bleeding can be an issue during this time, along with cramping. In other words they need to 'cut it some slack' during that time. It tends to eventually add to the effectiveness of surgery and there is growing evidence that it decreases the number of women needing repeat operations for recurrent endo symptoms.

Who do I advise to avoid a Mirena?

Obviously if you are trying to become pregnant it is a no brainer. The main group of women that I suggest do not have a Mirena are those who have a diagnosis of 'polycystic ovary syndrome' (PCOS), as it tends to aggravate acne or abnormal body and facial hair growth.

Is a Mirena right for you?

The only real way to know is to try one and see.



This is made by the same company that makes Mirena and is smaller in all dimensions. It is basically a "honey I've shrunk the Mirena" option and lasts for 3 years. Its smaller size means it is less likely to cause irritating painful cramps in younger women with a smaller uterus or it better fits inside the smaller uterine cavity. Otherise it does the same job as a Mirena.