A Randomized Trial of a Cervical Pessary to Prevent Preterm Singleton Birth

BACKGROUND Preterm birth is the leading cause of neonatal and infant death and of disability among survivors. It is unclear whether a pessary inserted around the cervix reduces the risk of preterm singleton birth. METHODS We conducted a multicenter, randomized, controlled trial comparing pessary placement with expectant management (control) in girls and women who were pregnant with singletons (singleton pregnancies) and who had a cervical length of 25 mm or less at 20 weeks 0 days to 24 weeks 6 days of gestation. Participants in either group who had a cervical length of 15 mm or less, at randomization or at subsequent visits, received treatment with vaginal progesterone. The primary outcome was spontaneous delivery before 34 weeks of gestation. RESULTS In an intention-to-treat analysis, there was no significant difference between the pessary group (465 participants) and the control group (467 participants) in the rate of spontaneous delivery before 34 weeks (12.0% and 10.8%, respectively; odds ratio in the pessary group, 1.12; 95% confidence interval, 0.75 to 1.69; P = 0.57). There were no significant differences in the rates of perinatal death (3.2% in the pessary group and 2.4% in the control group, P = 0.42), adverse neonatal outcome (6.7% and 5.7%, respectively; P = 0.55), or neonatal special care (11.6% and 12.9%, respectively; P = 0.59). The incidence of new or increased vaginal discharge was significantly higher in the pessary group than in the control group. CONCLUSIONS Among girls and women with singleton pregnancies who had a short cervix, a cervical pessary did not result in a lower rate of spontaneous early preterm delivery than the rate with expectant management.