Ethinylestradiol and desogestrel, alone or in combination with two doses of estriol. Effects on plasma proteins

Nineteen fertile women were treated with three differently composed oral contraceptives in a cross-over study and were randomly allocated to begin with one of the three preparations. The tablets contained 0.030 mg ethinylestradiol +0.15 mg desogestrel alone (A) or in combination with either 0.5 mg estriol (B) or 2 mg estriol (C). After two treatment cycles on each preparation, blood samples were obtained and analysed for ceruloplasmin, SHBG, prealbumin, transcortin and thyroxine-binding globulin. No differences were found in the induction of liver protein synthesis. It was concluded that the addition of estriol in doses of 0.5 or 2 mg did not influence the effects induced by ethinylestradiol.