Objective. To evaluate the efficiency of incorporating the micronized progesterone pragisan into a package of measures to prevent and treat miscarriage during early pregnancy. Subjects and methods. The investigation enrolled 30 women who had received first trimester threatened miscarriage treatment and 32 patients with clinical signs of threatened miscarriage who had refused treatment for various reasons. Threatened miscarriage was diagnosed based on complaints and ultrasound diagnosis (shortening of the cervix and dilation of the internal os). Results. The incorporation of the micronized progesterone pragisan into a package of measures aimed at preserving and prolonging pregnancy showed its high efficacy in patients with threatened miscarriage. Pregnancy could be preserved and prolonged to full term by 29 out of the 30 women with threatened miscarriage in the pragisan group and by only 19 (59.4%) in the group of those who had refused treatment. The timely restoration of vaginal biocenosis was also shown to contribute to the normalization of the course of pregnancy. Conclusion. The pronounced clinical efficacy, convenient dosing, and no adverse reactions of pragisan suggest that the drug may be incotporated into a package of measures to treat threatened miscarriage. © Bionika Media Ltd.