This randomized controlled trial compared the effectiveness of a cervical pessary and vaginal progesterone in preventing complications in women with multiple pregnancies and a shortened cervix. 276 multiple pregnancies (including seven triplets) were included in the study, and they were randomly divided into two groups - 138 women received a cervical pessary and 138 women received vaginal progesterone 200 mg per day. The primary objective was to determine whether any of the methods reduces the incidence of adverse perinatal outcomes. The results showed that a combined adverse perinatal outcome occurred in 19.7% of neonates in the pessary group compared with 13.7% in the progesterone group, the difference not being statistically significant. Preterm delivery rates were also not significantly different between the groups. However, in nulliparous women, the outcome was worse in the pessary group (30.0%) versus progesterone (15.9%). The authors conclude that the cervical pessary did not demonstrate superiority over vaginal progesterone in the prevention of perinatal complications in women with multiple pregnancies and a shortened cervix.