Mirena is a hormonal intrauterine device (IUD) manufactured by Bayer HealthCare Pharmaceuticals to prevent pregnancy. This flexible, T-shaped piece of plastic is implanted into a woman’s uterus and releases small amounts of levonorgestrel, a type of progestin (a synthetic hormone), over time.

After receiving FDA approval in 2000, Mirena became a popular form of birth control as an alternative to taking a daily pill because it lasts up to five years. Unfortunately, some women experience dangerous and potentially life-threatening complications when using Mirena IUD, leading many to file lawsuits.

In the past, Mirena IUDs were recommended only for women who had previously had at least one child. However, in June 2017, that recommendation was removed from the device’s prescribing information label.

Severe Mirena IUD Complications

Mirena IUDS are generally safe to use. Some patients have experienced the following severe Mirena IUD side effects, although these adverse effects are not common as a whole. While these side effects are specific to Mirena intrauterine devices, other devices (Kyleena, Skyla, and Liletta) may cause similar side effects and complications, as well.

Device Migration and Perforation

After implantation, it’s possible for the Mirena IUD to migrate from its position in the uterus. This can not only increase the risk of pregnancy, but can perforate the uterus. The implant may also enter the blood vessels, pelvis, abdominal cavity, or bladder. Women who have Mirena implanted immediately after delivering a child have an increased risk of uterine perforation for up to six months after delivery.

Migration and/or perforation can cause pain, abscesses, adhesions, infection, and damage to the intestines and nearby organs, requiring surgery to correct. In fact, some women have needed multiple surgeries because the IUD can become difficult to locate and extract. Bayer claims migration of the Mirena IUD is a rare complication, but a study published by Ronald Reagan UCLA Medical Center’s Department of Radiology found it to be more frequent.

Device Expulsion

The body may spontaneously expel the IUD, effectively ceasing the woman’s protection against pregnancy. Approximately 6% of Mirena users experience this complication, with those who have never given birth being at a higher risk. Device expulsion can lead to symptoms including bleeding or spotting, cramping, and pain during sexual intercourse.

Breast Cancer

Spontaneous reports of breast cancer surfaced during post-marketing experiences with Mirena. Since these are voluntary reports from a population of uncertain size, experts cannot use the data to reliably estimate the frequency of this complication, or establish a definite relationship to drug exposure.

That said, the U.S. Food and Drug Administration (FDA) warns that women who currently have or have had breast cancer, or who have a suspicion of breast cancer, should not use hormonal contraception because the disease involves a hormone-sensitive tumor.

Pseudotumor Cerebri

Research studies have linked Mirena to an increase of pressure in the skull, known as pseudotumor cerebri (PTC) or idiopathic intracranial hypertension. Symptoms mimic that of a brain tumor and include:

  • Vision loss and blindness
  • Double vision
  • Spotted or blurred vision
  • Severe headaches and migraines
  • Tinnitus, or a ringing in the ears
  • Swelling of the optic disk (papilledema)

Case studies dating back to 1995 show a relationship between levonorgestrel implants and PTC. One report in The New England Journal of Medicine highlights severe headaches and vision problems experienced by two women ages 16 and 19 who were otherwise in generally good health.

Pregnancy Complications

In addition to unintended pregnancy, Mirena can cause premature delivery, miscarriage, and sepsis (an extreme bodily response to an infection). When a woman with a Mirena implant becomes pregnant, doctors recommend the surgical removal of the fertilized egg to avoid a septic abortion, a life-threatening condition in which the uterus becomes septic, endangering both the mother and the unborn child.

Half of the pregnancies that occur with Mirena are ectopic (also known as a tubal pregnancy), in which the egg becomes fertilized outside the uterus, threatening the mother’s life. These women usually require surgery to remove the fertilized egg, and risk infertility.

Mirena IUD Bleeding

It’s quite common for Mirena to cause irregular bleeding for three to six months after implantation. In fact, the FDA has received over 45,000 reports of women suffering from bleeding complications, ranging from minor to life threatening. Mirena IUD bleeding patterns include:

  • Spotting
  • Irregular bleeding
  • Heavy bleeding
  • Continuous bleeding
  • Frequent menstruation
  • Oligomenorrhea (infrequent periods)
  • Amenorrhea (the absence of periods)

While the continual hormone release may be responsible for the bleeding, it can also be caused by other Mirena IUD complications, including:

  • Device migration into the abdomen
  • The device becoming embedded in the uterine wall
  • Endometrial changes
  • Inflammation
  • Infection
  • Miscarriage
  • Ovarian cysts
  • Perforated intestinal wall

For the 20% of Mirena users who experience amenorrhea or oligomenorrhea, close monitoring is recommended for the first year after implantation to ensure pregnancy does not result. Those who experience excessive Mirena IUD bleeding may require medical attention. Some patients need surgery to remove the device if their bleeding is severe. Because of these risks, it’s important to disclose any medications you may be taking before insertion. Prescription blood thinners, and even some OTC medications can increase your risk of severe bleeding with an IUD.

In the case with Xarelto, there is no antidote to stop bleeding once it starts, posing a serious health risk to women. The lack of an antidote, and inadequate safety disclosures have lead over 18,000 women to bring lawsuits against the manufacturers of Xarelto

Pelvic Inflammatory Disease (PID)

Slightly less than 1% of Mirena users contract a serious infection called pelvic inflammatory disease (PID) within three weeks after implantation. The FDA warns women with a history of the disease to avoid using Mirena. Any bacterial infection that affects the female reproductive system can result in PID, damaging the uterus, ovaries, and fallopian tubes, and causing infertility.

Weight Gain

Clinical studies show that slightly less than 5% of women gain weight on Mirena. In one medical review published in 2016, researchers found the average weight gain was 4.4 pounds at 6 to 12 months.

Other Common Side Effects

Other common, though less serious Mirena IUD side effects Include:

  • Abdominal and pelvic pain
  • Acne
  • Breast tenderness
  • Mood changes
  • Nausea
  • Ovarian cysts
  • Vaginal discharge

FDA Warnings about Mirena IUDs

A large part of the FDA’s regulatory role is ensuring that promotional materials disclose risks and other pertinent data about drugs and medical devices. In 2009, the agency was forced to issue a strict warning regarding the use of Mirena after it became clear that Bayer failed to communicate Mirena’s inherent risks and side effects, thereby promoting more efficacy than was accurate. Without this disclosure, the manufacturer may have misled the public about the efficacy and/or consequences of the IUD in its suggested use.

Specifically, Bayer’s initial marketing for Mirena IUDs failed to indicate that Mirena should only be used for up to five years before replacement, implying that the device can be used indefinitely. Bayer further failed to market that Mirena is primarily recommended for women who have had at least one child, subsequently implying the device is suitable for all women. Many of the allegations raised in Mirena injury lawsuits across the country allege that Bayer sold the IUD without providing adequate warnings and information, which led to serious Mirena IUD complications.