BACKGROUND AND PURPOSE: 

• Successful strategies to prevent preterm birth in women with threatened preterm birth and short cervix are not currently available  
• Pratcorona et al. (AJOG, 2018) assessed whether cervical pessaries can help prevent spontaneous preterm birth in women at high risk following an episode of threatened preterm birth and cervical shortening

METHODS: 

• Prospective open randomized controlled trial (RCT) 
• Participants 
  • Singleton pregnancies between 24w0d and 33w6d gestation  
  • Arrested preterm labor episode 
    • Regular uterine contractions, with at least 2 painful contractions in 10 minutes averaged over 30 minutes 
    • No contractins 6 to 12 hours after tocolytics stopped  
  • Short cervix  
    • ≤25 mm between 24w0d–29w6d  
    • ≤15 mm between 30w0d–33w6d  
• Routine management of threatened labor 
  • Hospitalization | Tocolytics (atosiban) | Corticosteroids | Antibiotics if needed 
• Patients were randomized to receive 
  • Cervical pressary (placement confirmed by TV ultrasound)  
  • Routine management  
• Primary outcome: Spontaneous preterm birth rate <34 weeks 
• Secondary outcomes: 
  • Spontaneous preterm birth <28 and 37 weeks | PPROM | Neonatal morbidity and mortality outcomes | Maternal adverse events

RESULTS: 

• 357 pregnant women were involved in the study 
  • 179 pessary | 178 no treatment  
• There was no significant difference between the pessary and routine management groups for spontaneous preterm birth rate <34 weeks 
  • 10.7% in the pessary group vs 13.7% in the control group  
    • Relative risk (RR) 0.78; 95% Cl, 0.45-1.3) 
• Spontaneous preterm birth <37 weeks occurred less frequently in the pessary group 
  •  14.7% in the pessary group vs 25.1% in the control group  
  • RR 0.58; 95% CI, 0.38-0.90 (P = .01) 
• PPROM was significantly lower in pessary group 
  • 2.3% in the pessary group vs 8.0% in the control group  
  • RR 0.28; 95% CI, 0.09-0.84 (P = .01) 
• Readmission for new threatened preterm labor episodes ≥1 was significantly reduced in the pessary group  
  • 4.5% in the pessary group vs 20.0% in the control group  
  • RR 0.23; 95% CI, 0.11-0.47 (P < .0001) 
• There was no case of pessary withdrawal  
  • Some patients had moderate, white, nonodorous discharge  
  • 19.8% did perceive the presence of the pessary  
  • No difference in bleeding  
  • While there was pain reported on removal, patients with pessary would recommend to others 
• There was no reduction in neonatal morbidity 
  • Study underpowered to assess most neonatal endpoints

CONCLUSION: 

• Pessary use did not lower spontaneous preterm birth rate <34 weeks in women with a short cervix and threatened preterm labor episode 
• However, pessary use did significantly reduce PPROM and spontaneous preterm birth rate in the late preterm period  
• Larger trials may be needed to demonstrate neonatal benefit  
• Authors conclude  

…the cervical pessary could be considered an affordable, safe, and reliable tool for reducing the risk of late spontaneous preterm birth in singleton pregnancies of women with short cervical length remaining after a threatened preterm labor, a high-risk population in which no intervention has proven efficacious to date.

Learn More – Primary Sources: 

Cervical pessary to reduce preterm birth <34 weeks of gestation after an episode of preterm labor and a short cervix: a randomized controlled trial

Related ObG Topics:

PoPPS Study: Does Pessary Use In Women with a Short Cervical Length Prevent Preterm Birth?

Short Cervix and Risk for Preterm Birth: Do Pessaries Work? 

SMFM Statement: Choice of Progestogen for Preterm Birth Prevention