Cardiovascular disease and use of oral contraceptives : WHO collaborative study

ABSTRACT

Considerable evidence from the United Kingdom and North America has shown that oral contraceptive use is associated with an increased risk of cardiovascular disease. However, since little is known about the link between the two in other parts of the world, WHO initiated a hospital-based case-control study in three centres in Mexico, Hong Kong, and the German Democratic Republic. Both cases and controls were asked about their past and current use of contraception as well as details on a number of potential confounding factors