Oral Contraceptives and Increased Formation of Soluble Fibrin

Abstract
Soluble fibrin was measured weekly for two months in 12 normal women and in 12 women on combined oestrogen-progestogen therapy (Ortho-Novin, Norinyl, Enavid, Ovral, Ovulen, Demulen). Plasma soluble fibrin concentration in women on oral contraceptives showed an increase of 97·2% (P <0·001) above that of normal women. In three cases, where each woman on the oral contraceptive served as her own control, stopping medication led to a return to normal of the plasma content of soluble fibrin.