The evidence is only circumstantial. Apparent interaction between warfarin and levonorgestrel used for emergency contraception. Third generation oral contraceptives do increase the risk of venous thromboembolism. Timing of thromboprophylaxis for general surgery should be discussed with anaesthetists. Incidence of venous thromboembolism in users of combined oral contraceptives.
Risk is particularly high with first use of oral contraceptives.
JICK H. Incidence of venous thromboembolism in users of combined oral contraceptives. Methods for identifying cases and estimating person time at risk must be detailed. Admission for and mortality from primary venous thromboembolism in women of fertile age in Denmark, 1977-95. Admission for and mortality from primary venous thromboembolism in women of fertile age in Denmark, 1977-95. DoH seems to have underestimated incidence of venous thromboembolism in users of combined oral contraceptives.