RESUMEN
OBJECTIVES: To observe the modifications in cervical length (CL) in patients with and without cervical pessary (Arabin® ASQ 65/25/32) and correlate these modifications with gestational age at delivery. STUDY DESIGN: Prospective study of asymptomatic singleton pregnancies (PECEP-Trial) between weeks 20 + 0 and 23 + 6 with maternal short cervix (<25 mm) randomised into two groups: expectant management and cervical pessary. RESULTS: This study included 380 pregnant women: 190 with pessary and 190 without pessary. Mean CL in both groups at the time of randomisation showed no statistically-significant differences (pessary group: 19.0 mm and management group: 19.0 mm; p = 0.9). Mean CL measured after randomisation was 15.4 mm in patients of the expectant management group and 21.5 mm in the pessary group. These differences were statistically significant (p < 0.0001). When means at randomisation and at the second measurement were compared, CL had decreased by 3.6 mm in the expectant management group and increased by 2.6 mm in the pessary group; this difference was statistically significant (p < 0.0001). Coefficients of correlation showed that among patients of both groups with the same CL at 20 weeks of gestation, those with a pessary gave birth later. CONCLUSIONS: Insertion of an Arabin cervical pessary increased CL in asymptomatic patients with a short cervix, which correlated with shorter gestational age at delivery. The cervical pessary halted the progressive decrease in CL, which correlated with longer gestational age at delivery.