16 Oct I have been having heavy periods for the past one year. Ultrasound examination of the pelvis is normal. My gynaecologist suggested that I should have the Mirena inserted in my womb. He said this would reduce the blood flow. What is Mirena? How does it work? Any side effects?
Mirena is a small T-shaped plastic intra-uterine device (IUD) (see figure) which is inserted by the gynaecologist into the womb for contraceptive purpose. It releases progestogen, a hormone similar to the natural progesterone produced by the ovaries and can be used in the treatment of patients with heavy menses.
Every month, the lining of the womb(endometrium) thickens during the first half of the menstrual cycle to prepare for ovulation. If ovulation takes place and the egg is not fertilized, the endometrium is shed off as menstrual flow. The progestogen which Mirena releases acts on the endometrium and reduces its thickness. With less thickening of the lining, the menstrual flow is thus reduced. After a year of Mirena insertion, menstrual flow may stop completely in one out of five women.
Side effects of Mirena include:
- Irregular vaginal bleeding: For the first 3 to 6 months, the monthly period may become irregular. There may be frequent spotting or light bleeding. After a while, these episodes become less frequent and menses may completely stop.
- Pain or bleeding may occur during or immediately after the insertion.
- Ovarian cyst: About 12 out of 100 women may develop cysts in the ovary. These cysts are non-cancerous and usually disappear on their own in a month or two. Occasionally, the cysts may persist and cause pain requiring surgical removal.
- Pelvic inflammatory disease (PID). IUD users may get pelvic infection which is usually sexually transmitted. If left untreated, life-threatening sepsis may occasionally set in.
- Perforation. Very rarely, Mirena may go through the wall of the uterus in a condition known as perforation. This may cause abdominal pain.
- Expulsion: Mirena may be expelled by the womb and may no longer prevent pregnancy.