Women using birth control pills Yasmin and Yaz have a one-and-a-half to three times higher risk of blood clots than women on other oral contraceptives, a Health Canada review says.
Yasmin and Yaz contain the hormone drospirenone while levonorgestrel is used in other forms of birth control pills.
Health Canada says blood clots are a rare, but well-known side effect for all birth control pills.
"To put this into perspective, if the estimated risk of developing a blood clot among women taking a levonorgestrel-containing birth control pill is 1 in 10,000 women per year, as some studies have estimated, then the risk in women taking a drospirenone birth control pill is about 1.5 to 3 women in 10,000 per year," Health Canada said in a release Monday.
The drug labels for Yasmin and Yaz have been updated to include the information from the latest study.
Health Canada says all women should talk to a health care professional about their blood clot risk when deciding on an oral contraceptive.
The U.S. Food and Drug Administration is also reviewing birth-control drugs containing drospirenone and it expected to unveil its findings later this week.
