Comparison of the efficacy of sublingual, oral, and vaginal administration of misoprostol in the medical treatment of missed abortion during first trimester of pregnancy: A randomized clinical trial study

Background: this study was aimed at comparing the efficacy of different routes of misoprostol administration, including sublingual, oral, and vaginal, on the induction of medical abortion in the first trimester of pregnancy. materials and methods: this open‑label, randomized clinical trial study was performed on 172 individuals in three parallel groups of vaginal, sublingual, and oral administration of misoprostol. the participants were randomized using permuted blocks of six. a dose of 600 μg of misoprostol every 6 h (maximum of 4 doses) was administrated to each group. higham chart and demographic questionnaires were completed by the investigator. data were analyzed using stata software version 12. results: the mean age of the participants was 29.81 ± 6.7 years, and the mean gestational age was 8.45 ± 2.32 weeks. we found a significant difference regarding the abortion success rate and the time interval between the administration of the drug among three groups (p = 0.036 and < 0.001 in turn). there was no statistically significant difference between the three groups in terms of severity and duration of vaginal bleeding until day 7 after induction (p = 0.091 and 0.143, respectively). furthermore, we found statistically significant differences in some drugs, which induced side effects namely vomiting and headache, between the three groups (p = 0.032 and 0.028 in turn). conclusion: the findings suggest that vaginal administration of misoprostol is more successful than the sublingual and oral route for complete abortion; vaginal administration of misoprostol is an appropriate alternative to curettage.