Cervical Pessary for Preventing Preterm Birth in Singleton Pregnancies with Short Cervical Length: A Systematic Review and Meta-analysis

OBJECTIVES: To evaluate the effectiveness of cervical pessary for preventing spontaneous preterm birth (SPTB) in singleton gestations with a second trimester short cervix. METHODS: Electronic databases were searched from their inception until February 2016. We included randomized clinical trials (RCTs) comparing the use of the cervical pessary with expectant management in singletons pregnancies with transvaginal ultrasound cervical length (TVU CL) ≤25 mm. The primary outcome was incidence of SPTB <34 weeks. The summary measures were reported as relative risk (RR) with 95% confidence interval (CI). RESULTS: Three RCTs (n = 1,420) were included. The mean gestational age (GA) at randomization was approximately 22 weeks. The Arabin pessary was used as intervention in all three trials, and was removed by vaginal examination at approximately 37 weeks. Cervical pessary was not associated with prevention of SPTB <37 (20.2% vs 50.2%; RR 0.50, 95% CI 0.23 to 1.09), <34, <32, and <28 weeks, compared to no pessary. No differences were found in the mean of GA at, interval from randomization to delivery, incidence of preterm premature rupture of membranes and of cesarean delivery, and in neonatal outcomes. The Arabin pessary was associated with a significantly higher risk of vaginal discharge. CONCLUSIONS: In singleton pregnancies with a TVU CL ≤25mm at 200 -246 weeks, the Arabin pessary does not reduce the rate of spontaneous preterm delivery or improve perinatal outcome. Individual patient data meta-analysis may clarify whether cervical pessary may be beneficial in subgroups, such as only singleton gestations without prior SPTB or by different CL cutoffs

Cervical pessaries to prevent preterm birth in women with a multiple pregnancy: a per-protocol analysis of a randomized clinical trial

IntroductionWe recently showed that a cervical pessary prevents preterm birth and reduces poor neonatal outcomes in women with a twin pregnancy and a short cervix ( <38 mm). The objective of this study was to evaluate the full potential treatment effect of the pessary in the whole group and in women with a short cervix. Material and methodsWe performed a per-protocol analysis of a multicenter randomized controlled trial (ProTWIN trial, NTR1858) where we excluded women who were allocated to the pessary but never had it placed. Women who had the pessary removed before 36 gestational weeks and did not deliver within 7 days after removal, were excluded. Analyses were performed on all women and in those with a cervical length <38 mm. ResultsIn 23 (6%) women the pessary was not placed. In women with a cervical length <38 mm (25th percentile) the pessary reduced poor perinatal outcome (relative risk 0.32, 95% confidence interval 0.13-0.78) and birth at <32 weeks (relative risk 0.41, 95% confidence interval 0.20-0.87). After excluding 47 (12%) women, the time to delivery was longer in the pessary group than in the control group (whole group: hazard ratio 0.68, 95% confidence interval 0.55-0.82, cervical length <38 mm: hazard ratio 0.35, 95% confidence interval 0.22-0.57). ConclusionsThe analysis confirms the principal findings of the intention-to-treat analysis. Time to delivery was longer in the pessary group than in the control group when censored data were used. This implies the pessary should not be removed until labor is eviden