The use of oral contraceptives is a well-established acquired risk factor for venous
thrombosis. In 1995, a number of epidemiological studies were published which suggested …

In a recently published paper in Blood, 1 Kemmeren et al elegantly studied the effect of
second-and third-generation oral contraceptives (OCs) on hemostatic variables that probe …

The discovery of plasma resistance towards activated protein C, APC resistance, and its
main genetic background, the presence of a single-point mutation in the gene coding for …

Hereditary activated protein C (APC) resistance is an established risk factor of venous
thromboembolism, mostly associated with the Arg506-Gln mutation of the factor V gene [1]. A …

Resistance to activated protein C (APC) is at present considered the most frequent
laboratory abnormality in patients with deep‐vein thrombosis. An increased risk for venous …

Objective: The object of the study was to determine the effects of oral contraceptives on
blood coagulation, in particular on the protein C pathway. Study Design: Plasma samples …

To the Editor: Recently, Jensen et al.[1] published a study in which they assessed the effect
of switching from combined oral contraceptives to the combined contraceptive vaginal ring …

SIR-Jorquera and colleagues (Oct 22, p 1162) describe a modification of the test proposed
by Dahlback to improve sensitivity and to use the test in patients on oral anticoagulants. We …

Sir—Peter Clark and colleagues (Jan 23, p 292) 1 call attention to acquired activated protein-
C (APC) resistance during pregnancy, which they recorded as an increased resistance to …

Acquired resistance to the anticoagulant action of activated protein C (APC) has been
proposed to explain the increased risk of venous thrombosis associated with pregnancy …