With more than 60 percent of women in their “child-bearing years” using some form of contraceptive — most turning toward an oral pill for the prevention of pregnancy — a new study suggests that the hormones could come with unintended effects.

Photo credit: Shutterstock

Photo credit: Shutterstock

Research by scientists at the Fred Hutchison Cancer Research Center found that some versions of the birth control pill could increase a woman’s risk for breast cancer by 50 percent.

The versions of oral contraceptives specifically cited in the study published in the journal Cancer Research were those with “high doses of estrogen, some types of progestin and certain dosing schedules,” according to the research center.

Before anyone who takes birth control pills panics, both the study authors and a representative from the American College of Obstetricians and Gynecologists gave further explanations.

“Our study results need to be interpreted cautiously,” Dr. Elisabeth Beaber, lead author of the study, told the research center. “This is an important contribution, but it is not yet at the scale where it is … changing any clinical recommendations.”

Dr. Owen Montgomery, a spokesman for the American College of Obstetricians and Gynecologists, told the research center that most women don’t take the type of pills the study would label associated with a higher risk.

“I can tell you, I haven’t seen a woman in 20 years on a high-dose pill,” Montgomery added. 

Low-dose estrogen birth control pills were not associated with an increased cancer risk, Beaber told Reuters Health.

According to the study abstract, researchers looked at 1,102 women age 20 to 49 years old who were diagnosed with breast cancer from 1990 to 2009. From these cases, the researchers concluded that certain birth control types increase breast cancer risk.

The study authors believe that the information would need to be replicated in other populations before there are any recommended changes to birth control use.

“Talk to your provider about the type of birth control you’re using and make sure it meets your needs in light of this new information,” Montgomery told the research center.

Reuters also pointed out that with less than 1 percent of women under 40 years old developing breast cancer, a doubled risk from certain types of birth control still keeps the odds relatively low. Dr. David Grimes told Reuters that it was so low it could be dismissed as random chance.

“Weak associations, consistent with noise and not signal, were the overall finding,” Grimes told the news outlet.

This is not the first study to draw a link between birth control pills and breast cancer risk. In fact, Fred Hutchison Cancer Research Center scientists have put out two other recent studies along these lines.