RESUMEN
INTRODUCTION: Preterm labor is defined as delivery before 37 weeks of gestation. Up to 17% of twin pregnancy are preterm. Arabin cervical pessary has been proven as preventing preterm labor in singleton pregnancies. The benefit of it in twin pregnancy is controversial. OBJECTIVES: The purpose of this study was to compare the rate of preterm delivery in twin gestation with short cervical length in Israel- one center utilized the combined treatment of Arabin cervical pessary and vaginal progesterone (study group) and the others utilized vaginal progesterone approach (control group). METHODS: Multi-center retrospective cohort study, including "Shamir", "Wolfson", "Shaare Zedek" and "Galilee" medical centers, between the years 2012-2016. Inclusion criteria were twin gestations and short cervical length (<25mm) between 16-28 weeks' gestation. RESULTS: The study group included 68 women, the control group 78 women. The study group had shorter cervical length at intervention in comparison to the control group (13.6 ± 5.9 vs. 16.5 ± 5.7, respectively, p = .002). The treatment started later for the study group compared to the control group (23.2 +2.2 vs 22.6 +3.0). CONCLUSIONS: Despite having shorter cervical length at recruitment, the rate of spontaneous delivery < 34-weeks' gestation was similar in both groups (36.8 vs. 37.2%, respectively). DISCUSSION: Considering the conclusion in this research it seems that the combination of the mechanical effect of the pessary by embracing the cervix, keeping the cervical mucus, bending it in a way that the pressure is towards the anterior cervical wall together with the progestative effect which increases the estrogen/progesterone ratio, creating uterine quiescence and keeping the structural connective tissue of the cervix have an added benefit. It seems that the combined use of Arabin cervical pessary and vaginal progesterone in twin pregnancy with short cervical length have a synergic effect which may have a benefit in preventing preterm labor. The combination of cervical pessary and progesterone does not negatively affect twin pregnancy outcome and does not cause preterm birth.