Progesterone and cervical Pessary in twins: a prospective and randomized study to prevent preterm Biirth

Abstract

The frequency of twin pregnancies has increased significantly, especially because of the assisted reproduction and advanced maternal age at conception. The twin pregnancies are responsible for 25 % of all preterm birth. Consequently, these are more associated with perinatal mortality and morbidity when compared to single pregnancies.Additionally, the short cervix ( < 25 mm) in singleton and twin pregnancies are associated with significantly increased preterm birth.Randomized controlled trials in singleton pregnancies reported that profilatic cervical cerclage and vaginal progesterone reduce significantly the rate of early preterm birth. In twin pregnancies, vaginal progesterone and profilatic cerclage have been shown to be ineffective in prevention of preterm birth.However, individual pacient data meta-analyses reported in a subgroup of women with twin pregancies and short cervix, that vaginal progesterone reduce significantly adverse neonatal outcomes. Nowadays, the effet of cervical pessary is contraditory, mainly in women with short cervix.Objetive: The objetive of this study is to test the hypothesis that the insertion of a cervical pessary combined with vaginal progesterone, in twin pregnancies with short cervix would reduce the spontaneus preterm birth < 34 weeks' gestacion.Study design: This is a randomized prospective trial at São Paulo University Medical School. This trial will involve 131 women with twins pregnancies and short cervix between 16 and 27 weeks and 6 days' gestacion. Women with twin pregnancy and short cervix will be assigned randomly to daily vaginal progesterone (400g) combined with insertion of cervical pessary or expectant manegement until 36 weeks' gestacion.The primary outcome to compare the rate of spontaneus delivery < 34 weeks' gestacion between the treatment and nontreatment groups.The secondary outcome is to compare the morbidity and mortality between this groups. (AU)