Cyclical Changes in Coagulation Factors Associated with the Use of Progestational Agents

Abstract

The activity of factors II, VII, VIII, IX, X and fibrinogen and factor VIII antigen levels were followed during a single menstrual cycle in three females using oral contraceptive agents, and in two controls. Marked cyclical variation occurred in the activity of factor VII and VIII, but not in factor VIII antigen levels. Less marked changes occurred in factor II and fibrinogen.

Changes in Coagulation Factors and Platelet Function in Response to Progestational Agents

“…Sequential studies performed in our laboratory [16] have demonstrated marked variation in the level of certain clotting factors, espe cially factors VII and VIII throughout an oral contraceptive cycle. It is therefore important that the time of sampling in the menstrual cycle should be standard.…”