Summary of findings for the main comparison. Nitric oxide donors versus placebo for cervical ripening and induction of labour.
| Nitric oxide donors for cervical ripening and induction of labour | ||||||
| Patient or population: pregnant women undergoing cervical ripening and induction of labour Setting: outpatient and inpatient settings in India, UK, Sweden, Sri Lanka, France and Iran Intervention: nitric oxide donors Comparison: placebo/no intervention | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with placebo/no intervention (all women) | Risk with (1.1) Nitric oxide donors | |||||
| Vaginal delivery not achieved in 24 hours | Study population | RR 0.97 (0.83 to 1.15) | 238 (1 RCT) | ⊕⊕⊝⊝ LOW 1 | ||
| 711 per 1000 | 689 per 1000 (590 to 817) | |||||
| Uterine hyperstimulation with FHR changes | Study population | RR 0.09 (0.01 to 1.62) | 300 (2 RCTs) | ⊕⊕⊝⊝ LOW 2 3 | ||
| 33 per 1000 | 3 per 1000 (1 to 54) | |||||
| Caesarean section | Study population | RR 0.99 (0.88 to 1.11) | 2624 (9 RCTs) | ⊕⊕⊕⊝ MODERATE 4 | ||
| 280 per 1000 | 277 per 1000 (246 to 311) | |||||
| Serious neonatal morbidity/perinatal death | Study population | RR 1.61 (0.08 to 33.26) | 1712 (2 RCTs) | ⊕⊕⊝⊝ LOW 5 6 | ||
| 1 per 1000 | 2 per 1000 (0 to 39) | |||||
| Serious maternal morbidity or death | Study population | not estimable | 1362 (1 RCT) | There were no events for this outcome. | ||
| 0 per 1000 | 0 per 1000 (0 to 0) | |||||
| *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; FHR: Fetal heart rate; RCT: randomised controlled trial; RR: Risk 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 Only one study with few events, small sample size and wide confidence interval.
2 High risk of bias for allocation concealment and blinding.
3 Only two studies with few or no events, small sample size and wide confidence interval.
4 High risk of bias for allocation concealment, blinding and selective outcome reporting.
5 Confidence intervals do not overlap (opposite directions of effect) and I2 = 48%.
6 Only two studies with few events and wide confidence intervals.