For years, birth control pills have been linked to an increased risk of breast cancer, though newer drugs containing smaller doses of estrogen and progestin were assumed to be safer.
A new study suggests they aren't. Researchers in Denmark reviewed public health records for 1.8 million women, using prescription data to identify users of hormonal contraceptive drugs, including intrauterine devices that release progestin alone, reports Bloomberg.
Overall, the risk of breast cancer for these women was 20% higher than for those who never used contraceptives, a similar rate as for women who took older versions of the drugs.
Though it's a small increase—representing one extra case per 7,690 women—it's enough that study author Lina Morch suggests women who have a strong family history of breast cancer consider other birth control methods.
The American College of Obstetricians and Gynecologists also tells the New York Times that hormonal contraceptives are "among the most safe, effective and accessible options available." But Morch says that it's important women know the risks involved, including that longer use heightens the risk of breast cancer.
Use for 10 years or more was linked to a 38% higher risk, while increased risks were found to persist for years after prolonged use ended, says Morch.
It Was All Downhill From There
This article originally appeared on Newser: The Pill, IUDs Raise Risk of Breast Cancer