Oral contraception with a triphasic combination of gestodene and ethinyl estradiol: results of a multicenter clinical study.

The clinical effects of a low-dose triphasic oral contraceptive containing the new progestogen gestodene and ethinyl estradiol were investigated in phase II and III multicenter studies. The phase II study compared the clinical effects in 377 women taking this new compound during 2123 cycles with the effects of a low-dose triphasic combination of levonorgestrel and ethinyl estradiol in 362 women treated in 2088 cycles. The discontinuation rates after 6 months were similar in the two groups, and no major differences in side effects were observed. Cycle control was better during intake of the gestodene-containing preparation, since spotting occurred less frequently (P less than .05). The phase III investigation comprised 1921 women representing a total of 27,308 cycles. The Pearl index was 0.05. During the 24-month trial, 243 women (12.7%) dropped out of the study because of side effects, mainly bleeding disturbances (6.0%), headache (2.2%), and breast tension (2.0%). The results of these studies indicate that the triphasic combination of gestodene and ethinyl estradiol is well tolerated and provides high contraceptive efficacy and good cycle control.