What is Mirena and what is it used for?

Mirena is a small, flexible T-shaped plastic device containing levonorgestrel, a progesterone hormone. It is similar to a Copper T, but instead of copper, it releases progesterone directly inside the uterus.

Mirena slowly releases the hormone into the uterine cavity, causing thinning of the uterine lining (endometrium). Very little hormone enters the bloodstream, thereby reducing systemic side effects and avoiding the need for daily medication.

Mirena can be used for:

Treatment of heavy menstrual bleeding
Reduction of pain associated with periods
Management of endometrial hyperplasia due to hormonal imbalance
Protection of the uterus in menopausal women on hormone replacement therapy
Highly effective birth control

Steps of the procedure

This is an outpatient procedure and usually does not require anaesthesia. The cervix is visualised and cleaned with an antiseptic solution, and the device is gently inserted into the uterine cavity. The threads are trimmed short.

The entire procedure takes only a few minutes. Occasionally, an instrument may be used to steady the cervix if insertion is difficult.

After insertion, the device itself is not felt, but the threads should be felt inside the vagina. Women are advised to check for the threads monthly and report if they are not felt.

After insertion

Mirena is best inserted within seven days from the start of menstruation. Mild discomfort or cramping and minimal spotting may occur for a day or two after insertion. Normal daily activities can be resumed immediately.

Mirena does not interfere with sexual intercourse and remains effective for up to five years. Removal can be done easily in an outpatient setting.

How effective is Mirena?

90% of women report significant improvement in pain
70% experience lighter menstrual periods
30% may stop having periods after a few months (this is not harmful)
For contraception, 1–2 per 1000 women may become pregnant each year

Rarely, pregnancies that occur may be ectopic (outside the uterus).

Are there any risks?

Serious side effects are uncommon. Some women may experience irregular spotting for 3–6 months after insertion.

Infection and uterine perforation are rare
Expulsion of the device occurs in less than 3% of women
About 12% may develop ovarian cysts, which usually resolve on their own

Follow-up

A follow-up visit is usually advised after six weeks to assess symptoms and confirm correct placement of the device.