RESUMO
Progestin-only minipills have been available for over three decades, yet their use has been limited, because of a documented lower efficacy when compared to pills that combine estrogen and progestin. The availability of a new low-dose progestin-only minipill containing 75 microg desogestrel (DSG) offers a new perspective, since, in a large multicenter study, this minipill gave a crude Pearl index of 0.41 and an adjusted one of 0.14, which is comparable to indices found in clinical trials of oral contraceptives. This minipill also allows for a 12-hour tolerance time in taking the pill. The high effectiveness of the DSG minipill is attributable to an almost constant inhibition of ovulation, as shown by the absence of elevated progesterone circulating levels and inhibition of follicular growth in the vast majority of cycles studied. Since irregular bleeding patterns are observed with all minipills, patterns experienced with DSG 75 microg have been compared to those obtained with levonogestrel 30 microg. As expected, the more pronounced ovarian inhibition produced wider bleeding variability with DSG, but also less bleeding overall. The DSG minipill is suitable for lactating women and represents a valuable addition to oral contraception.
