Mirena is a hormonal intrauterine device (IUD), manufactured by Bayer Healthcare Pharmaceuticals. It is a small, T-shaped that is implanted in the uterus. The device is made of a medication-eluting polymer (a type of plastic) containing the hormonal contraceptive levonorgesterel. The polymer allows the device to be flexible enough to implant in the uterus and releases the medication over a long period of time.
Levonorgesterel is a progestin hormone used for birth control and is usually taken by mouth. It has also been used in other birth control devices such as Norplant. Because the IUD releases the medication into the uterus, Mirena uses a smaller amount of hormone than birth control pills at a daily rate of 20 mcg of hormone. Mirena will release hormones for up to five years when it requires replacement.
The Food and Drug Administration (FDA) approved Mirena in 2000. The first hormonal IUD, Progestasert was withdrawn from the market in 2001 as it only lasted for one year. Mirena was the only available hormonal IUD in the US until 2013 when the FDA approved Skyla, a lower level levonorgesterel IUD that is only good for three years.
The contraceptive levonorgesterel is a synthetic progestin type hormone which acts similar to naturally occurring progesterone in the body. Use of the contraceptive prevents the body from going through the normal menstrual cycle.
During the monthly cycle, progesterone and estrogen levels rise and fall in a rhythmic pattern. This causes an egg to be released from the ovary (ovulation). If it is not fertilized and implanted as a pregnancy, the lining of the uterus will be shed as the monthly bleeding called menstruation.
The levonorgesterel in Mirena that is released into the uterus works by:
- Altering or thinning the uterine wall
- Thickening cervical mucus to prevent any sperm from entering the uterus
- Decreasing the survival rate of sperm
It may also prevent ovulation due to systemic (body-wide) absorption of levonorgesterel, similar to the way oral contraceptives and other levonorgesterel devices work.
Changes in the lining of the uterus may also decrease menstrual bleeding. Many women who have Mirena do not have a normal menstruation period.
Mirena is implanted by a physician at a cost of approximately $800. Many insurance policies do not cover the procedure and the woman must pay for the device “out-of-pocket”. The device will last up to five years. When the woman wishes to remove it or it is time for replacement, the removal must also be done by a health care practitioner.
Normally Mirena is removed by simply pulling the attached string, which causes the flexible arms to bend to allow the device to slide out of the cervix. In some cases, the device can migrate or move out of the uterus or become implanted in the uterine wall. This will require surgical removal which can be permanently damaging.
History of Mirena and IUDs
IUD use world-wide is estimated at 160 million users with over two-thirds of those women living in China. In the US, about 5 percent of women using contraceptives use an IUD. Women living outside the US are twice as likely to use an IUD.
The first IUDs were developed in the 1900s but caused a number of severe injuries and were not widely used until the 1950s when plastics technology had advanced, allowing for a moldable plastic shape which was much better than previous IUD technology.
In the 1950s and 60s, a number of plastic IUDs were introduced including the Dalkon Shield, a barbaric looking device which was estimated to be used in over 3 million women. It ultimately caused multiple, severe bacterial infections resulting in several deaths, multiple cases of infertility, and thousands of lawsuits. The Dalkon Shield was withdrawn in 1974 after over 200 thousand lawsuits had been filed.
The T-shape IUD design was introduced during the 1960s with the addition of copper which was shown to be an effective spermicide. A copper IUD, known as Paragard is available for use in the US today. Copper is an effective contraceptive agent but is known to cause a number of problems including increased bleeding and localized reactions.
Hormonal IUDs were created in the 1970s in order to reduce menstrual bleeding associated with copper and simple plastic IUDs. The US market was highly skeptical of IUDs following the Dalkon Shield disaster but development continued in Europe.
Hormonal IUDs or Intrauterine Systems (IUS) as they are known in Europe were available for a decade prior to their approval in the US. Progestasert, the first IUD containing hormonal contraceptives on the US market required yearly replacement and was withdrawn shortly after Mirena was introduced in 2001.
In 2009 Mirena was approved to treat heavy menstrual bleeding in women already using an intrauterine device.
Serious Adverse Events and Complications of Mirena
Because Mirena is a hormonal birth control method, some side effects are related to the hormone. Most of these are not severe, however some adverse events caused by Mirena can be life-altering or even life-threatening.
Mild side effects include:
- Local irritation
- Irregular menstrual period and vaginal discharge
- Weight changes
- Mood changes
- Breast tenderness
More severe side effects of Mirena can be permanently damaging or even life threatening.
Mirena and Infections
Implantation of an intrauterine device such as Mirena may increase the risk of pelvic infection, especially within the first three weeks after insertion. Pelvic Inflammatory Disease (PID) is a bacterial infection that can result in damage to the female reproductive organs and may result in infertility. Women who have had PID are more likely to have it again and should not use Mirena or any IUD.
Mirena and Device Expulsion
Mirena may be spontaneously expelled from the uterus. About six percent of Mirena users experience expulsion. This may cause tissue tearing or other damage and result in bleeding. Symptoms may include bleeding, spotting, cramping, and pain during sexual intercourse. A routine check of the device string may indicate a shorter, lengthened or absent string. A woman who experiences expulsion will not be protected from pregnancy. Women who have not had a child have a higher risk for expulsion of Mirena.
Mirena and Pregnancy Complications
Mirena is reported to be effective over 99% of the time. The presence of hormones may damage a developing fetus which may result in miscarriage and may cause the uterus to become septic, resulting in a septic abortion, an extremely dangerous condition. If a pregnancy is allowed to proceed, there is a high risk of premature birth. If a pregnancy occurs during Mirena use, it is recommended that the woman undergo surgical zygote removal.
Though pregnancy is rare with Mirena use, an estimate half of Mirena related pregnancies are Ectopic. An ectopic pregnancy is often called “tubal” pregnancy as it often involves fertilized egg plantation in one of the fallopian tubes. An ectopic pregnancy is generally a medical emergency and often requires surgical removal of the fallopian tube which can result in infertility. Women who have had a previous ectopic pregnancy should not use Mirena.
Mirena and Device Migration
In addition to device expulsion, Mirena can migrate from its normal position in the uterus. This may cause perforation of the uterine wall. If the device perforates the uterine wall and enters the abdominal cavity, it may damage the bladder, blood vessels, intestines and other organs. This can result in significant pain and infection and will require surgical removal. In some cases, the surgery must be done as an emergency if the patient’s life is threatened and damage may be permanent and result in infertility. Some women may also require multiple surgeries to locate and remove the device and repair damage to organs and other tissue.
Women who use Mirena within six months after delivering a child are more likely to experience device migration.
In order to locate the device, radiologists use an ultrasound or X-ray. In some cases, women have had to undergo several surgeries because the device is difficult to locate and remove. The risk of perforation of the uterus is also increased in women who use Mirena immediately after delivering a child, and the risk is elevated for at least 6 months after delivery.
Mirena Warnings and Lawsuits
Since 2004, the FDA has received over 47 thousand reports of adverse events related to Mirena use. In 2009, the FDA issued a warning to its manufacturer, Bayer for overstating the effectiveness of the device and minimizing risks. Bayer had claimed in its “Simple Style” live marketing presentations targeting “busy moms” that the IUD would help women with increased libido and that they would “look and feel great”.
According to the warning letter, at least 5 percent of women using the Mirena IUD had reported decreased libido during clinical trials. The Division of Drug Marketing, Advertising, and Communications (DDMAC), a department of the FDA that reviews marketing plans and documents of pharmaceuticals had concluded that this program overstated Mirena benefits, while downplaying side effects.
Bayer has also been warned by the FDA regarding advertising for some of its other birth control products including Yasmin and Yaz oral contraceptives.
Hundreds of lawsuits have been filed against Bayer regarding Mirena. Some victims have received compensation for their injuries but hundreds more are in litigation and many more are expected. Mirena has been reported to be one of the top 20 search terms on the FDA’s website.
Approximately 500 federal lawsuits filed in various districts have been consolidated as multidistrict litigation (MDL) in the Southern District of New York, supervised by Judge Cathy Seibel.
Bayer had petitioned to have multiple lawsuits that were filed in New Jersey consolidated there as it is close to the company’s headquarters. That request was initially denied but more than 60 separate lawsuits were consolidated into multicounty litigation in Bergen County Superior Court.
Attorneys for plaintiffs in both the federal lawsuits and others filed against Bayer regarding Mirena claim that Bayer failed to warn women about the potential for injury including abcesses, infections, perforations, tubal pregnancies and other injuries and claim that the company released a device that was defective in design and that the company was aware of the dangerous risks.
Bayer is also accused of using misleading advertising which misrepresented benefits and concealed harmful effects.
Attorneys for the plaintiffs will be seeking actual damages (compensation for medical costs, lost wages and other costs) along with punitive damages (to punish the company) for willful endangerment that resulted in pain and suffering.