Warning over contraceptive with higher clot risk
Women are not routinely using the safest brand of contraceptive pill, according to a study aimed at assessing the risk of blood clots associated with the medication.
All types of the combined contraceptive pill carry a risk of venous thrombosis or venal blood clot, but some carry a higher risk than others.
The safest option, the researchers said, was the combination of hormones found in the widely used pills Ovranette, Microgynon 30 and Trinordial. These, known as second-generation pills, have a low dose of oestrogen combined with levonorgestrel, a type of progesterone.
Women most at risk are those on third-generation pills such as Marvalon, Mercilon and Femodin, the authors said. The study also found that Jasmine, a new pill on the market, carried a similar risk of blood clots to Marvalon and Mercilon.
Progesterone-only pills, which have a lower level of progesterone than the combined pill, and hormone-releasing intrauterine devices (IUDs) are not associated with any increased risk of blood clots.
More than 100 million women use the pill worldwide. Women taking the contraceptive pill have a five-fold increased risk of blood clots compared with non-users, the study says. But the researchers stressed that the absolute risk of blood clots with use of any type of oral contraceptive in young women is low, affecting less than one in 1,000 users. They recommend, for women of normal weight and no predisposition to blood clots, a low-dose combined pill.
Lynn Hearton, of the Family Planning Association, said: ‘Although the combined pill does slightly increase the risk of thrombosis, the risk is still really low.’