BOSTON (AP) _ The latest generation of birth control pills appears to carry a smaller risk of heart attack than its predecessor, a Dutch study found.
The study of 1,173 women found that those who took second-generation pills had 2 1/2 times the heart attack risk of other women. But women who took the current, third-generation pills had essentially the same risk as other women, according to findings published Thursday in The New England Journal of Medicine.
Second-generation pills, which often carry the hormone levonorgestrel, date back to the 1970s. Third-generation contraceptives, which often contain desogestrel or gestodene, became available first in Europe in the mid-1980s and then in the United States, mostly in the 1990s.
About 100 million women around the world take the pill. Some are using the new versions, some the older ones.
Despite the findings, doctors said women should not necessarily switch to the newer pill. For one thing, an earlier study came to an opposite conclusion, finding a greater risk of heart attack in the third generation than in the second.
Other studies have shown a greater risk of lung-threatening blood clots with third-generation pills, especially in young women and those who are just starting the pill, cautioned the Dutch study's lead investigator, Dr. Frits Rosendaal of Leiden University Medical Center.
Lisa Chasan-Taber, an epidemiologist at the University of Massachusetts at Amhert, said women might want to consult their doctors on whether to switch to a different pill.
In any event, the risk of a heart attack from oral contraceptives now in use is very slight, probably adding no more than two heart attacks in 10,000 women over the course of a year.
The elevated heart attack risk is thought to stem from the blood-clotting effects of the pill.