Low-Dose Birth Control Pill May Up Heart Risk
But Researchers Say Risk of Heart Attack and Stroke Still Very Low for Most Women
July 7, 2005 -- Low-dose birth control pills are widely considered to be safer than the pill of the past, but a new review suggests that they still carry an increased risk for heart attack and stroke.
The risk appears to be quite small for most women, but it could be much higher for those already at risk for heart disease, researchers report. That includes overweight women at high risk for diabetes and women with a condition known as polycystic ovary syndrome.
Researcher John E. Nestler, MD, tells WebMD that studies are needed to better understand the risks associated with oral contraceptive use in these women.
"I think it is quite reasonable to assume that women who already have an increased risk for cardiac disease may be particularly vulnerable," he tells WebMD. "But there is not a single study out there looking specifically at oral contraceptive use in this group."
Doubling of Risk
Heart attack and stroke are rare in women of childbearing age, but they do occur. Studies clearly link earlier generations of the pill to an increased risk for these events. Less is known, however, about the risks associated with today's oral contraceptives, which contain much lower doses of estrogen than the earlier versions of the pill.
In an effort to clarify this risk, Nestler and colleagues from Virginia Commonwealth University and the University of Sherbrooke in Sherbrooke, Quebec, reviewed relevant studies that included women taking low-dose oral contraceptives conducted between 1980 and 2002.
Overall, the risk of having a heart attack or stroke was found to be twice as high for low-dose oral contraceptive users as for nonusers. The risk returned to normal, however, when the women stopped taking the pill.
To put the findings in perspective, if a 40-year-old woman's risk of dying from heart disease in 10 years is five in 1,000, it increases to 10 in 1,000 if she takes low-dose oral contraception.
"Obviously, this risk is extremely small, so I don't think this finding will have an impact on the use of birth control pills for contraception [among women of normal risk]," Nestler says.