The cardiovascular and thromboembolic risks of oral contraception: a review.

After evaluating the various epidemiological methods used to assess the side effects of oral contraceptives (OCs) this literature review devotes brief paragraphs to the following cardiovascular complications of OCs: thromboembolic disorders (blood clotting factors venous thromboembolic disease coronary thrombosis subarachnoid hemorrhage and cerebral thrombosis and smoking-associated cardiovascular disease) and hypertension. Numerous reports suggest that use of a combined OC increases plasma concentrations of fibrinogen factors V VII VIII IX and X and increases platelet adhesiveness. Reports that the combined pill can interfere with fibrinolysis have also been published. Both superficial and deep vein thromboses are associated with OC use. In fact the risk of superficial leg vein thrombosis increases by 50% with OC use (combined preparation). The risk of deep vein thrombosis increases 5-6 times from 20/100000-110/100000. The link between coronary (arterial) thrombosis and OC use is probably a result of the pills synergism with various other factors including smoking obesity hypertension hypercholesterol stress or diabetes. The relative risk of oral pill use and heart attack is 2.8. The incidence of strokes seemed higher with OC use but so far studies are too small to state any connection except for 1 particular type of cerebrovascular accident the subarachnoid hemorrhage which has an increased incidence not only among present OC users but among ever users. The synergistic effects of smoking and OC use resulting in Cardiovascular disease are discussed and the mortality rate for smokers using OCs vs. smokers not using OCs was significantly higher (P < .01). For nonsmokers there was not a statistically significant difference. The estrogen content of OCs is thought responsible for the 2-59 times greater risk of high blood pressure among OC users recently reported. The overall mortality rate for ever users of OCs in Britain was 58/100000 vs. 48.9/100.000 for never users.