A study of blood coagulation parameters.

The object of this study was to determine the presence or absence of abnormalities in a variety of blood coagulation parameters in women on contraceptive medication. A prospective double-blind study involving a control group with a total study enrollment of 211 women during a 29 month period was established. Although research has not proved that changes in coagulation parameters will cause abnormal clotting in normal patients, a pattern appears to be developing involving antithrombin III determinations. Corresponding patterns do not appear to be developing in the other blood coagulation parameters.