The Mirena IUD is a T-shaped device that is inserted into the uterus to prevent pregnancy. It contains a synthetic form of the hormone progestin. With the IUD in place, a woman does not ovulate, or release eggs from the ovaries into the fallopian tubes and the the uterus. The hormone in Mirena alters the lining of the uterus to prevent the attachment of a fertilized egg, should fertilization occur. According to the Epigee website, Mirena has been found to be as effective as sterilization. The Mirena IUD does have the potential for a small number of complications.
In the rare event that a woman gets pregnant while the Mirena IUD is in place, it has a high likelihood of being an ectopic pregnancy. This refers to a pregnancy that takes place outside of the uterus, which according to RxList.com, occurs in one out of every 60 pregnancies that develop in Mirena users. An ectopic pregnancy is very serious and can result in death or even impair future fertility. Women who have had an ectopic pregnancy before should not use Mirena, nor should women with an irregularly shaped uterus, according to the U.S. Food and Drug Administration (FDA). Before the IUD is placed, a doctor will examine the uterus to assess whether the woman is an ideal candidate for the IUD. This helps minimize the risk of ectopic pregnancy.
LIke other hormone-based contraception choices, Mirena has the potential for side effects from the hormones it emits while placed in the uterus. Some side effects include cramping, severe pain, menstrual changes, spotting, breakthrough bleeding, heavier or lighter menstrual flow, or the reduction or increase in menstrual cramping, according to RxList.com.
A small percentage of women using Mirena may develop an ovarian cyst, according to RxList.com. Some cysts disappear on their own within a few months, but others cause pain and require surgical removal. During insertion, germs or bacteria may enter the uterus and cause pelvic-inflammatory disease (PID). PID is a serious infection and can be transmitted sexually. Complications of the disease include infertility, ectopic pregnancy, or constant pelvic pain, according to the FDA. Some women require nothing more than antibiotic treatment and the removal of the IUD, but other women may need a hysterectomy to remove the uterus. In rare cases, PID leads to further complications that can result in death.
If Mirena falls out of place it can become lodged in the uterine wall. This is called perforation. Surgery to remove the Mirena device may be required. Other complications, as indicated by RxList.com, from perforation may include the obstruction of the intestines, perforation of the intestines and the development of scar tissue wherever the device embeds itself.