Hormonal birth control has allowed millions worldwide to manage their menstrual cycles and control their reproductive futures.But as with any drug, there are pros and cons for doctors and patients to carefully consider.While strong evidence suggests that hormonal birth control provides numerous benefits, some scientists argue that there are potential risks, like depression or stroke, that have been "inadequately addressed".One concerning connection that keeps popping up in observational population studies around the world is the development of a rare yet treatable brain tumor called meningioma.Researchers at the Danish Medicines Agency have now combed through 25 years' worth of health data in Denmark, covering roughly three million females, to clear up the picture.Their findings are published in JAMA Network Open.The nationwide study is the first of its kind to show that only certain types of contraceptives are indeed linked to this type of tumor.
Although the relative risk reported by the study is modest and the absolute risk is probably tiny, it is important to investigate further.Injectable birth control called medroxyprogesterone (brand name Depo-Provera) showed the strongest association with meningioma tumors, with a relative increase in risk of about 4-fold.According to the Danish study, weaker associations exist for combined oral contraceptives and the mini-pill, with a relative risk increase of 1.5-fold. Importantly, these risks only persisted while participants were actively using contraception. The elevated risk generally seems to disappear within five years of stopping a contraceptive progestogen."While a 4-fold relative increase in risk seems very high, the absolute risk of meningioma is small," explains cancer epidemiologist Paul Pharoah from Cedars-Sinai Health Sciences University in the US. He explains that about 5 women per 1,000 will develop a meningioma in their lifetime.That only increases to 6 women per 1,000 women using medroxyprogesterone from ages 25 to 44."These very small increases in risk need to be balanced against the benefits of different forms of contraception," says Pharoah. "It is important that women do not stop using their birth control pills without consulting their doctor."Not only are meningioma tumors rare, but when they do occur, they are also typically benign in roughly 90 percent of cases.On occasion, however, these tumors can cause seizures and cognitive issues, so they are taken seriously. Meningiomas are usually removed surgically or treated with radiation therapy.Thousands of women who say they were diagnosed with an intracranial meningioma after receiving Depo-Provera injections have filed lawsuits against Pfizer since 2024.
