BACKGROUND AND PURPOSE:

• A short cervix in women with previous preterm birth significantly raises the risk of recurrence by 3 fold
• Conde-Agudelo et al. (AJOG 2018) compared the efficacy of vaginal progesterone and cerclage in prevention of preterm birth and adverse perinatal outcomes in this group of previous preterm birth and short cervix

METHODS:

• Systematic Review and meta-analysis
  • Participants: Women with singleton gestation, previous spontaneous preterm birth and a second trimester short cervix (<25 mm) on ultrasound
  • Literary search included RCTs with a primary aim of preventing preterm birth in the above group
• Daily dose of vaginal progesterone used in the trials varied from 90 to 200 mg, administered from 18–25 to 34–36 weeks of gestation
• Trials used both McDonald and Shirodkar technique
• Primary outcomes
  • Preterm birth <35 weeks of gestation
  • Perinatal mortality
• Secondary outcomes
  • Preterm birth <37, <32, and <28 weeks of gestation
  • Respiratory distress syndrome and other adverse neonatal outcomes
  • Composite perinatal morbidity and mortality
• Pooled relative risk (RRs) with 95% confidence intervals were calculated

RESULTS:

• Five trials comparing vaginal progesterone vs placebo (265 women) and 5 comparing cerclage vs no cerclage (504 women) were included

Direct Comparisons

• Vaginal progesterone, compared with placebo
  • Significantly reduced the risk of preterm birth <35 and <32 weeks of gestation, composite perinatal morbidity, mortality, neonatal sepsis, composite neonatal morbidity, and admission to the neonatal intensive care unit (RRs from 0.29 to 0.68)
• Cerclage, compared with no cerclage
  • Significantly decreased the risk of preterm birth <35, <37, <32, and <28 weeks of gestation, composite perinatal morbidity/mortality, birthweight <1500 g (RRs from 0.64 to 0.70)
• There were no differences in grade III/IV intraventricular hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia, and birthweight <2500 g regardless of progesterone or cerclage

Indirect Comparison Between Cerclage and Progesterone

• Adjusted indirect comparison meta-analyses showed no differences between vaginal progesterone and cerclage
  • Preventing preterm birth <35 weeks of gestation (RR, 0.97; 95% CI, 0.66–1.44; P =.93)
  • Perinatal death (RR, 0.97; 95% CI, 0.35–2.69; P =.96)
• There were no differences in secondary outcomes

CONCLUSION:

• Vaginal progesterone and cerclage are equally effective for the prevention of preterm birth in women with singleton pregnancies, previous preterm birth and short cervix
• These findings agree with a previous, smaller RCT and Cochrane review comparing vaginal progesterone to cerclage that likewise did not show any difference in this population
• There is data suggesting that there may be increased use of tocolysis and preterm PROM when using cerclage
• Clinical implications of this study suggest either progesterone or cerclage may be used but further properly powered, large RCTs are required
  • In the interim, the data provided by this study may serve as the best evidenced based guide to care

Learn More – Primary Sources:

Vaginal progesterone is as effective as cervical cerclage to prevent preterm birth in women with a singleton gestation, previous spontaneous preterm birth, and a short cervix: updated indirect comparison meta-analysis

Related ObG Topics:

Do Progestogens Prevent Preterm Birth in Symptomatic Pregnancies with a Short Cervix?

Does Vaginal Progesterone Improve Birth Outcomes for Mothers with Short Cervix?

Meta-analysis: Cerclage for Short Cervix but Without History of Preterm Birth 

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