Mirena is an intrauterine device (IUD) that can be used to prevent pregnancy. Mirena is made by Bayer Healthcare, and combines both hormonal and barrier approaches to birth control. The Mirena IUD releases a progestin hormone called levonorgestre, which suppresses ovulation and thickens cervical mucus. In addition to the hormones being released, the actual device helps keeps sperm away from eggs in the event that a woman does ovulate. The manufacturers of Mirena explain that their device is more than 99 percent effective for up to five years. The Mirena contraceptive can cause some side effects in some women that may take time to get used to. If the side effects become bothersome, Mirena can be removed easily, in favor of another contraception method.
Irregular Bleeding
Mirena users may find that their periods become irregular--the first six months of using the contraceptive may lead to spotting between periods--or stop completely once the IUD has been inserted by their doctor. The drug that is released affects the uterine lining, making it thinner. Women who still get their periods may experience a flow that is much less voluminous than before they chose Mirena. Menstruation most often returns to normal after the IUD is removed.
Infection
Bayer Healthcare, the manufacturer of Mirena, reported in 2006 that a very small percentage of women using their product developed streptoccocal infection leading to sepsis--a body-wide infection--after having the IUD inserted. Infection is a rare side effect of using Mirena due to bacteria that is possibly introduced into the uterus during the insertion process. Symptoms of infection include pain, fever, chills and muscle aches.
Ovarian Cysts
Women who use Mirena may experience ovarian cysts. Some cysts may cause pain and cramping, while others may not even be noticed. This side effect is not serious in most cases, though abdominal pain that is persistent could indicate infection or other complications. Women who have pain that does not let up should contact their gynecologist to discuss their discomfort.
Uterine Perforation
Sometimes, Mirena can shift and result in a small tear in the uterine wall. This is called uterine perforation, and is most likely to occur during insertion. Uterine perforation that occurs after the IUD has been placed can lead to a malfunction of the device, which may allow pregnancy if the time is right. Mirena should be removed in the case of a uterine perforation so that the tear can be treated.
