Inhibition of Tissue-Type Plasminogen Activator in Plasma of Women Using Oral Contraceptives and in Normal Women During a Menstrual Cycle

Tissue-type plasminogen activator (t-PA) inhibition in plasma was assessed in 15 normal women and in 10 women using oral contraceptives (OC) containing 30 micrograms ethinyl oestradiol and 150 micrograms levo-norgestrel. The levels of t-PA inhibition were significantly lower in the OC group with marked fluctuations related to the hormone cycle. Normal women had only minor fluctuations.