PREDICTION OF CHANGES IN LEVELS OF HEMOSTATIC VARIABLES DURING NATURAL MENSTRUAL-CYCLE AND OVARIAN HYPERSTIMULATION

To find if there is a relation between levels of haemostatic variables at low and high hormonal levels (oestradiol and progesterone) in an i ndividual, blood samples were drawn from 12 women repeatedly during on e menstrual cycle (Study. I) and from 14 women undergoing in vitro fer tilization before hormonal stimulation and daily during the periovulat ory period (Study II). Regression coefficients were calculated between minimum (independent) and maximum (dependent) values in both studies. In Study II highly significant regression coefficients were found bet ween oestradiol minimum (pretreatment) and maximum (median 105 and 473 0 pmol/l, respectively) for coagulation factors FVIII, von Willebrand Factor (antigen), FVII (activity and antigen), fibrinogen, protein C, protein S (free), antithrombin, plasminogen and plasminogen activator inhibitor-1; furthermore, between progesterone-minimum at day -3 or -2 (related to ovum pick up) and maximum (median 4.7 and 98 nmol/l, resp ectively) for FVIII, von Willebrand Factor, FVII (activity and antigen ), protein C, protein S (free), and plasminogen. In Study I, where muc h lower hormonal levels were obtained at maximum (oestradiol median 29 7 pmol/l and and progesterone 47 nmol/l), the same pattern was observe d especially for FVIII, FX, fibrinogen, plasminogen and plasmin inhibi tor. Thus, the concentration of a haemostatic variable at a low oestra diol or progesterone level can predict the level at a high hormonal le vel.