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b. Thromboembolism An increased risk of thromboembolic and thrombotic disease associated with the use of oral contraceptives is well established. Case control studies have found the relative risk of users compared to nonusers to be 3 for the first episode of superficial venous thrombosis, 4 to 11 for deep vein thrombosis or pulmonary embolism, and 1.5 to 6 for women with predisposing conditions for venous thromboembolic disease. Cohort studies have shown the relative risk to be somewhat lower, about 3 for new cases and about 4.5 for new cases requiring hospitalization. The risk of thromboembolic disease associated with oral contracep-tives is not related to length of use and disappears after pill use is stopped. A two-to four-fold increase in relative risk of post-operative thromboembolic complications has been reported with the use of oral contraceptives. T he relative risk of venous thrombosis in women who have predisposing conditions is twice that of women without such medical conditions. If feasible, oral contra-ceptives should be discontinued at least four weeks prior to and for two weeks after elective surgery of a type associated with an increase in risk of thromboembolism and during and following prolonged immobi-lization. Since the immediate postpartum period is also associated with an increased risk of thromboem-bolism, oral contraceptives should be started no earlier than four weeks after delivery in women who elect not to breast feed. After an induced or spontaneous abortion that occurs at or after 20 weeks gestation, hormonal contraceptives may be started either on Day 21 post-abortion or on the first day of the first spon-taneous menstruation, whichever comes first. Text Continues Below
c. Cerebrovascular diseases Oral contraceptives have been shown to increase both the relative and attributable risks of cerebrovascular events (thrombotic and hemorrhagic strokes), although, in general, the risk is greatest among older (> 35 years), hypertensive women who also smoke. Hypertension was found to be a risk factor for both users and nonusers, for both types of strokes, and smoking interacted to increase the risk of stroke. Page: << Prev | 1 | 2 | 3 | 4 | 5 | Next >>
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