the effect of progesterone suppositories on threatened abortion: a randomized clinical trial

background: threatened abortion is a common complication of pregnancy. in order to prevent miscarriage in the cases with threatened abortion, this study was conducted to determine whether progesterone suppository is effective in allowing pregnancy to proceed beyond week 20 in women with threatened abortion. methods: this single-blind clinical trial study was done on 60 pregnant women with threatened abortion. pregnant women, who had vaginal bleeding until 20 weeks of their pregnancy, were assessed for inclusion. participants were divided into two groups by random allocation; the control group, which did not undergo any treatment and the case group. the case group was given 400 mg of vaginal progesterone suppository (cyclogest) each day until their bleeding stopped in less than one week. participants were followed up until the end of their pregnancy. the treatment was considered successful if pregnancy continued beyond 20 weeks of gestation. qualitative and quantitative variables were analyzed statistically by chi square and t- test respectively. the p-values of less than 0.05 were considered significant. results: there was no statistically significant difference between the case and the control groups in terms of background variables. the number of abortions in the case group (6 cases, 20%) was lower than the control group which had 10 abortions (33.3%). conclusion: the study demonstrated that the rate of abortion was reduced in women treated with progesterone suppositories. however, the difference was not statistically significant.