A 13-month multicenter clinical experience of a low-dose monophasic oral contraceptive containing 20 microg ethinylestradiol and 75 microg gestodene in Latin American women

This prospective, multicenter study was conducted to evaluate the contraceptive reliability, cycle control and tolerability of a 21-day oral contraceptive regimen containing 20 microg ethinylestradiol and 75 microg gestodene in four Latin American countries (Mexico, Argentina, Brazil and Colombia). Participants took trial medication daily for 21 days. Contraceptive efficacy, cycle control and tolerability were evaluated over a period of 13 cycles. Efficacy data gathered from 5,109 treatment cycles were obtained from 393 participants. The trial medication proved to be an effective contraceptive and provided good cycle control. One pregnancy because of poor compliance was recorded. This resulted in a study Pearl index of 0.25. Forty-six percent of Latin American women reported one intracyclic spotting bleeding episode and 37.6% reported one intracyclic breakthrough bleeding (medium/excessive bleeding) episode during cycles 2-4 (primary target). Overall, intracyclic bleeding was reported in 41%. Overall, there was a trend towards a lower incidence of spotting in all the countries and this difference had statistical significance between Argentina and the others three countries (p < 0.05) during cycles 2-4. This trend was also apparent with respect to breakthrough bleeding, but again the difference did not achieve statistical significance. The discontinuation rate because of adverse events was low (3%); no serious adverse events were reported. More than 78% of the women in the four countries maintained constant body weight or lost weight (2 kg) during the study. The treatment effect on blood pressure was negligible. There were no appreciable changes in mean laboratory values over the course of the study.