BACKGROUND AND PURPOSE:

• Transvaginal cervical length is a predictor for spontaneous preterm birth (SPTB)
• In singleton pregnancies without PTB, vaginal progesterone prevents SPTB
  • Prior PTB, and cervical length < 25mm, cerclage associated with prevention of recurrence
• RCT data on pessaries for SPTB prevention are contradictory
• Dugoff et al. (Ultrasound Obstet Gynecol, 2017) assessed if pessary use prevents preterm birth in singleton gestations with short cervical length and no SPTB history

METHODS:

• Open-label multicenter randomized trial of asymptomatic singleton births (2014-2016)
• Inclusion criteria
  • Transvaginal ultrasound cervical length ≤ 25 mm at 18w0d-23w6d
  • No prior spontaneous preterm birth
  • No complications (e.g., ruptured membranes, fetal anomalies, bleeding)
• Subjects were randomized to receive either
  • Bioteque cup pessary
  • No pessary
• Vaginal progesterone was recommended to women with a cervical length ≤20mm
• Primary outcome was preterm birth < 37 weeks
• Secondary outcomes
  • PTB <34, <28 and <24 weeks; SPTB <37, <34, <28 and <24 weeks; gestational age at delivery; birth weight; chorioamnionitis; genitourinary infections; intrauterine fetal demise and cesarean delivery
  • Adverse neonatal outcomes were also assessed including neonatal death (birth to 28 days of age) as well as a composite adverse outcome measure
• NOTE: The trial was stopped early before complete enrollment
  • Two primary sites halted enrollment due to competing NICHD studies after their inclusion in to the NICHD MFM network

RESULTS:

• 391 (92.7 %) women met eligibility criteria and 122 (31.2 %) agreed to randomization
• Baseline characteristics were similar between pessary and no pessary groups
• There were no significant differences between the pessary and no pessary groups in rates of preterm birth <37 weeks (43% vs 40%, relative risk 1.09, 95% CI 0.71-1.68),
• There were no significant differences in secondary outcomes

CONCLUSION:

• Possible reasons that there was no difference in outcomes
  • Progesterone use
  • Enrolled women without previous SPTB but still may be a high-risk population
  • Earlier gestational age at time of enrollment / African American inner city population
  • PPROM rate higher than other RCTs
  • Present study used Bioteque and not Arabin pessary
  • Small sample size due to interruption of study prior to complete enrollment
• Pessary use was not associated with a decreased risk for preterm birth for singleton asymptomatic gestations with short transvaginal ultrasound cervical length without prior spontaneous preterm birth

Learn More – Primary Sources:

Prevention of Preterm Birth with Pessary in Singletons (PoPPS): a randomized controlled trial.

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