This Birth Control Was Linked To A Rare Brain Tumor — An MD Explains

The decision to use a hormonal contraceptive—and the decision on which one to use—is a highly personal one. IUDs (short for intrauterine device) are a popular option, as they're often a set it (yes, it's a painful processes and access to pain management options needs to be more widespread), and, hopefully, forget it option that lasts for years.

And while these contraceptives have been well-studied in preventing pregnancies, there is still a lot we need to learn about other effects (positive or negative) that these medications can have on health.

A new study1 published in JAMA Open Network analyzed health records from nearly 3 million women in Denmark over 25 years and found that several hormonal contraceptives (particularly those containing certain progestins, synthetic forms of progesterone) were associated with a higher risk of developing meningioma, a rare type of brain tumor.

"A meningioma is a tumor of the lining of the brain," explains Natalie Crawford, M.D., a board-certified OB/GYN and reproductive endocrinologist. "It's benign about 90% of the time, and it's not common, with only 13 to 18 cases per 100,000 women a year."

Before you panic or consider having your IUD removed, here's what the findings actually mean.

What did the study find?

Researchers identified more than 1,400 women diagnosed with meningioma and compared their contraceptive use with nearly 15,000 women who did not develop the tumor.

Overall, they found that several hormonal contraceptives were associated with a higher likelihood of meningioma, particularly among current or recent users.

The strongest association was seen with the injectable contraceptive Depo-Provera (medroxyprogesterone acetate), which was linked to more than four times the odds of developing a meningioma compared to nonusers.

Researchers also found an association with higher-dose levonorgestrel-releasing IUDs (52-milligram devices sold under brand names like Mirena and Liletta), while lower-dose hormonal IUDs were not associated with an increased risk.

Why progestins may increase risk

Previous research has suggested that prolonged exposure to high doses of progestins may encourage the growth of certain meningiomas that have progesterone receptors.

"The concern is that long-term progestin exposure may increase the risk of a meningioma, and the strongest association was seen with the Depo-Provera injection," Crawford says. She notes that the association with higher-dose hormonal IUDs was much smaller.

"Since the baseline risk is very small, this doesn't account for a large increase in personal risk if you are using an IUD," Crawford explains. "The study's own math reveals that for most women on a hormonal IUD, you'd need tens of thousands of users every year to see one extra meningioma."

Should you stop using your hormonal IUD?

Hormonal IUDs remain among the most effective reversible forms of birth control available, and they're also commonly prescribed to manage heavy menstrual bleeding, painful periods, and other gynecologic conditions.

"The benefits of a hormonal IUD are that they are a highly effective contraception and can be a treatment for legitimate medical concerns," Crawford says. "But women should be aware of all possible risks so they can make the best decision for their own health."

She recommends speaking with your health care provider if you have additional risk factors. "If you have a higher-dose IUD and a personal or family history of meningioma, or you develop new symptoms like persistent headaches, vision changes, or seizures, bring this up with your doctor to discuss the next steps," Crawford says.

The takeaway

This large study suggests that some hormonal contraceptives (especially Depo-Provera and higher-dose levonorgestrel IUDs) may be associated with a slightly increased risk of meningioma. But because this type of brain tumor is rare to begin with, the increase in an individual's absolute risk remains very small. For most women, hormonal birth control continues to offer benefits that outweigh the potential risks.

And its important to have informed conversation with your health care provider about which option is the best fit for your health history and goals.