To evaluate effectiveness of combined treatment with cervical pessary (CP) and vaginal Progesterone (VP) for the prevention of preterm birth in singleton pregnancies with cervical consistency index (CCI) ≤ 5th percentile at 11–13 weeks' gestation. Prospective study from January 2016 to February 2017 was performed and transvaginal CCI and cervical length (CL) measurement were taken at 11–13.6 weeks' gestation in 615 singleton pregnancies. Patients with CCI ≤ 5th percentile were offered combined treatment with CP and VG 200 mg/day. VP was given until 34 weeks; CP was removed at 36 weeks or at the onset of labour. Patients with uterine contractions, bleeding or premature rupture of membranes were excluded. Preterm birth defined as born before 37 weeks of gestation, was match (1:3) by gestational age and CCI. 36 pregnant women of study group (who received treatment) had an average CL measurement of 37.4 mm, CCI of 51% and the mean gestational age at enrolment was 12.3 weeks compared to the control group (12 patients who did not receive treatment) 40.4 mm, 53% and 12.1 weeks respectively. Combined treatment compared to no treatment was associated with a statistically significant increase at the gestational age at delivery (33.3 VS 28.4 weeks; p <0.001). Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.