Cardiovascular risk and the use of oral contraceptives

The use of combined oral contraceptives (COCs) is associated with approximately 2-fold and over 4-fold increased relative risks of arterial and venous thromboembolic events, respectively. The highest risk of venous thromboembolism occurs in the first year of use (OR: 4.17) and is reduced to 2.76 over baseline risk after 4 years of therapy. The risk of myocardial infarction does not correlate to the length of therapy and disappears after treatment termination. Most of women, using COCs, have low absolute cardiovascular risks and benefits outweigh the risk associated with this method of birth control. However, in some cases, COCs may be contraindicated due to excessively increased cardiovascular risks. Current users of COCs, older than 35 years, appear to show an estimated 2.5-fold and 10-fold increased risk of venous thromboembolism in comparison to younger than 35 years COCs non-users and users, respectively. COCs users, who are current smokers, have 10-fold increased risk of myocardial infarction, whereas the risk of stroke increases nearly 3-fold. The presence of poorly controlled hypertension is associated with approximately 3-fold increased risks of myocardial infarction and ischemic stroke, while the risk of haemorrhagic stroke rises 15-fold. In women suffering from hypertension, discontinuation of COCs may improve blood pressure control. Women, who had their blood pressure measured before COCs use, have 2-2.5-fold decreased risk of myocardial infarction and ischaemic stroke. In women with multiple cardiovascular risk factors the use of progestogen-only contraceptives (POCs) should be considered. POC therapy is associated with substantially less risk of cardiovascular events than COCs.