RESULTS	The AUC ( 0,24 h ) and Cmax of ethinyloestradiol remained unchanged during all study cycles , whereas the AUC ( 0,24 h ) and Cmax of 3-ketodesogestrel decreased significantly from 31.2 ng ml-1 h to 17.7 ng x ml-1 h ( 43.9 % ; 95 % confidence interval ( CI ) -49.3 , -38.5 , P = 0.001 ) and from 3.6 ng x ml -1 to 3.0 ng x ml -1 ( 17.8 % ; CI -29.9 , -5.7 , P = 0.005 ) , respectively , during cycle A and by 41.7 % ( CI -47.9 , -35.6 ; P = 0.001 ) and by 22.8 % ( CI -31.2 , -13.3 ; P < 0.001 ) during cycle B respectively , compared with the control cycle .\