Multicenter trial of a monophasic oral contraceptive containing ethinyl estradiol and desogestrel.

A clinical trial was conducted at 47 centers in 11 countries to assess the efficacy and acceptability of a monophasic oral contraceptive containing 30 micrograms ethinyl estradiol and 150 micrograms desogestrel. 1,613 women took part for a total of 23,258 cycles. One pregnancy occurred in a cycle where two consecutive tablets had been forgotten. Cycle control was excellent, with reported decreases in the duration and amount of withdrawal bleeding during consecutive treatment cycles and a low incidence of irregular bleeding. Blood pressure was not affected during 2 years of use. The incidence of minor side effects was already low in the first treatment cycle and decreased further in the subsequent cycles. The combination (Marvelon) was shown to be a very reliable and acceptable oral contraceptive.