Once women begin to use intrauterine devices (IUDs), such as Mirena or ParaGard birth control, they tend to stick with them for years at a time, according to the findings of a new study. 

In a study published earlier this month in the American Journal of Obstetrics & Gynecology, researchers from St. Louis looked at data on birth control use by more than 9,000 women over a three year period, finding that most women who used implantable devices or retrievable devices stuck with the birth control treatment.

Researchers found that nearly 70% of women stuck with the Mirena IUD or the ParaGard IUD for three years, while 56.2% of women who used the Implanon subdermal implant were still using it three years later.

The implants are promoted as long-acting form of birth control that helps women avoid the need to remember to take a daily birth control pill. Therefore, the findings are not overly suprising, since the devices are each designed to protect against pregnancy for more than three years.

Mirena IUD

Mirena is the best selling form of long-acting birth control sold in the United States, which is a T-shaped piece of plastic that releases the progestin levonorgestrel to avoid pregnancy for up to five years. Other variations of the long-term birth control implants are on the market, including Skyla, which is a newer IUD made by Bayer, which also makes the Mirena, as well as the ParaGard, which does not release levonorgestrel like the Mirena and Skyla IUDs.

Despite the ease of use associated with implanted birth control devices, there have also been linked to reports problems with Mirena IUDs, where the device may perforate the uterus or migrate out of position.

Bayer currently faces several thousand Mirena lawsuits that allege the drug maker failed to adequately warn about the risk of spontaneous migration that may occur months or even years after the devices is implanted. Each of the women allege that they suffered severe internal injuries when Mirena IUD migrated out of place, often resulting in the need for surgical removal.

Given the similar factual allegations raised in the cases, a series of Mirena bellwether trials are expected to begin in the second half of 2015, to help the parties gauge how juries may respond to certain evidence and testimony that is likely to be repeated throughout the litigation. If Bayer fails to reach Mirena settlements or otherwise resolve the litigation, the drug maker may face hundreds of individual trials throughout the United States.

Implanon

Implanon is a small, toothpick sized implant that is placed just under the skin in a woman’s upper arm. It is designed to release the progestin etonogestrel to prevent pregnancy for a three-year period. The birth control implant was approved by the FDA in July 2006, and an estimated 500,000 American women have had the birth control implant inserted.

Concerns have also been raised over the safety of this device, following reports of unwanted pregnancies and Implanon migration. In 2011, U.K. officials reported that nearly 600 women had indicated that they got pregnant even with the birth control device.

In addition, Implanon’s manufacturers, Merck and its Organon subsidiary, face a number of Implanon migration lawsuits from women who say the implant migrated away from the initial surgical sites and are now irretrievable, meaning that they may be infertile until the medication in the device runs out and are susceptible to a continuing risk of potential side effects.

There is also a risk that the implant could do internal damage to veins and arteries.

Tags: Bayer, Birth Control, Implanon, IUD, Merck, Mirena, Paragard, Skyla