Daily Reproductive Health Report
Contraception & Family Planning News Release
June 17, 2003
Women who take birth control pills with 50 micrograms of estrogen or less do not have an increased risk of stroke, compared with women who do not take oral contraceptives, according to a study published in the early online edition of the June 12 issue of the journal Stroke, Australia's Sunday Herald Sun reports (Papadakis, Sunday Herald Sun, 6/15). Lead author Dr. Sasitorn Siritho, a visiting fellow at the National Stroke Research Institute in West Heidelberg, Australia, and colleagues studied for five years 234 women between the ages of 15 and 55 who had had a stroke between 1984 and 1996 and 234 women of the same age who had not had a stroke. The researchers interviewed participants, obtained a list of previous and current medications used by the participants and family medical histories. Researchers found that women reporting that they currently used an oral contraceptive pill with less than 50 micrograms of estrogen did not have a statistically significant greater risk of ischemic stroke than those who did not take oral contraceptives (American Heart Association release, 6/12). Researchers also found no link between the number of years a woman has taken the pill and an increased likelihood of stroke, the Sun reports.
NSRI Director Geoffrey Donnan said, "Taking low-dose pills is safe with respect to the risk of developing a stroke" (Sunday Herald Sun, 6/15). Co-author Amanda Thrift, NSRI head of epidemiology, said that smoking, high blood pressure, diabetes and family history of stroke all increase a woman's risk of stroke and added that physicians should be cautious when prescribing low-dose oral contraceptives to women with such risk factors. Although the study's findings confirm the findings of similar studies, other studies have found that low estrogen oral contraceptives double a woman's chance of stroke. Other studies have shown that high estrogen oral contraceptives quadruple a woman's stroke risk. Siritho said that the results of the study could have underestimated the potential link between oral contraceptives and stroke due to participants failing to report past oral contraceptive use or the fact that so few of the participants were current oral contraceptive users (AHA release, 6/12).