Summary of findings for the main comparison. All routine Doppler ultrasound versus no Doppler ultrasound.
| All routine Doppler ultrasound versus no Doppler ultrasound | ||||||
| Patient or population: Pregnant women in unselected or low‐risk populations. Settings: Trials took place in Australia, France and the UK. Intervention: All routine Doppler ultrasound versus no Doppler ultrasound | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| No Doppler ultrasound | All routine Doppler ultrasound | |||||
| Perinatal death (stillbirth and neonatal death including anomalies) | Study population | RR 0.8 (0.35 to 1.83) | 11183 (4 studies) | ⊕⊕⊝⊝ low1,2 | ||
| 9 per 1000 | 7 per 1000 (3 to 16) | |||||
| Moderate | ||||||
| 7 per 1000 | 6 per 1000 (2 to 13) | |||||
| Serious neonatal morbidity | Study population | RR 0.99 (0.06 to 15.75) | 2016 (1 study) | ⊕⊕⊝⊝ low3 | ||
| 1 per 1000 | 1 per 1000 (0 to 16) | |||||
| Moderate | ||||||
| 1 per 1000 | 1 per 1000 (0 to 16) | |||||
| Stillbirth ‐ Fetal/umbilical vessels only | Study population | RR 0.34 (0.12 to 0.95) | 6877 (2 studies) | ⊕⊕⊕⊝ moderate4 | Evlidence for the stillbirth outcome has been graded separately according to subgroup. | |
| 4 per 1000 | 1 per 1000 (0 to 4) | |||||
| Moderate | ||||||
| 4 per 1000 | 1 per 1000 (0 to 4) | |||||
| Stillbirth ‐ Fetal/umbilical vessels + uterine artery | Study population | RR 1.41 (0.44 to 4.46) | 5276 (2 studies) | ⊕⊕⊝⊝ low2,5 | ||
| 6 per 1000 | 9 per 1000 (3 to 27) | |||||
| Moderate | ||||||
| 6 per 1000 | 8 per 1000 (3 to 27) | |||||
| Caesarean section (elective and emergency) | Study population | RR 0.98 (0.85 to 1.13) | 6373 (2 studies) | ⊕⊕⊕⊕ high | ||
| 108 per 1000 | 106 per 1000 (92 to 122) | |||||
| Moderate | ||||||
| 102 per 1000 | 100 per 1000 (87 to 115) | |||||
| Preterm birth (before 37 weeks) | Study population | RR 1.02 (0.86 to 1.21) | 12162 (4 studies) | ⊕⊕⊕⊕ high | ||
| 51 per 1000 | 52 per 1000 (44 to 62) | |||||
| Moderate | ||||||
| 47 per 1000 | 48 per 1000 (40 to 57) | |||||
| Neonatal admission to special care baby unit/neonatal intensive care unit | Study population | RR 0.99 (0.84 to 1.17) | 7477 (3 studies) | ⊕⊕⊕⊝ moderate4 | ||
| 66 per 1000 | 65 per 1000 (55 to 77) | |||||
| Moderate | ||||||
| 35 per 1000 | 35 per 1000 (29 to 41) | |||||
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (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; | ||||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
1 Statistical heterogeneity (I2 = 67%). 2 Wide confidence interval crossing the line of no effect. 3 Few events and wide confidence interval crossing the line of no effect (‐2). 4 Most of the pooled effect from a study with design limitations ‐ specifically problems with randomisation. 5 Statistical heterogeneity (I2 = 63%).