Summary of findings for the main comparison. Cerclage versus no cerclage.
| Cerclage versus no cerclage | ||||||
| Patient or population: preventing preterm birth in women with singleton pregnancy Setting: Belgium, Brazil, Canada, Chile, France, Greece, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, South Africa, Slovenia, UK, USA, Zimbabwe Intervention: cerclage Comparison: no cerclage | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with no cerclage (SoF outcomes) | Risk with cerclage | |||||
| All perinatal losses | Study population | RR 0.82 (0.65 to 1.04) | 2927 (10 RCTs) | ⊕⊕⊕⊝ MODERATE1 | ||
| 92 per 1000 | 75 per 1000 (60 to 96) | |||||
| Serious neonatal morbidity | Study population | RR 0.80 (0.55 to 1.18) | 883 (6 RCTs) | ⊕⊕⊝⊝ LOW 2 | ||
| 116 per 1000 | 93 per 1000 (64 to 136) | |||||
| Baby discharged home healthy | Study population | RR 1.02 (0.97 to 1.06) | 657 (4 RCTs) | ⊕⊕⊕⊝ MODERATE3 | ||
| 912 per 1000 | 930 per 1000 (885 to 967) | |||||
| Stillbirths | Study population | RR 0.89 (0.45 to 1.75) | 1803 (5 RCTs) | ⊕⊕⊝⊝ LOW 2 | ||
| 19 per 1000 | 17 per 1000 (9 to 33) | |||||
| Neonatal deaths before discharge | Study population | RR 0.85 (0.53 to 1.39) | 1714 (6 RCTs) | ⊕⊕⊝⊝ LOW 2 | ||
| 35 per 1000 | 30 per 1000 (19 to 49) | |||||
| Preterm birth before 34 completed weeks | Study population | average RR 0.77 (0.66 to 0.89) | 2415 (9 RCTs) | ⊕⊕⊕⊕ HIGH4 | ||
| 238 per 1000 | 183 per 1000 (157 to 212) | |||||
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio; OR: Odds ratio; | ||||||
| GRADE Working Group grades of evidence High quality: We are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect | ||||||
1 Wide confidence interval crossing the line of no effect (‐1).
2 Wide confidence interval crossing the line of no effect and small sample size (‐2)
3 Estimate based on small sample size (‐1).
4 Random effects model retained from primary analysis; there is no substantive difference in the risk estimate or the confidence intervals with fixed or random effects.