The Food and Drug Administration is reviewing the safety of certain types of birth control pills to see if they pose a greater risk of blood clots than competing pills.
The agency, in a safety announcement issued Tuesday, said it is focusing on pills that contain drospirenone, a female sex hormone known as a progestin. It is used in such Bayer products as Yaz (generic versions are Gianvi and Loryna) and Yasmin (generics are Ocella, Syeda, and Zarah).
Although all birth control pills increase the risk of blood clots, the FDA said two recent British Medical Journal studies showed that those containing drospirenone put women at two to three times greater risk than those taking another progestin, levonorgestrel. Other studies, however, have not shown increased risks, and the agency is evaluating the conflicting results.
Blood clots usually form in the lower leg or thigh, but can travel to other areas of the body such as the lungs. The FDA said the blood-clot symptoms include persistent leg pain, as well as severe chest pain and shortness of breath. The agency advises women considering whether to stop taking the pills to first consult a health care professional.
According to The Wall Street Journal, the FDA already is exploring the association of blood clots with hormonal contraception and its study is due out this summer. It will be based on findings from 800,000 U.S. women.
Bayer said its analysis of the scientific evidence shows that the blood-clot risk from taking pills containing drospirenone “is comparable” to that of other birth-control pills. On the other hand, last week the European Medicines Agency said the risk of developing blood clots from pills containing drospirenone was higher than from competing pills, but that the risk from any of the products was small.




