Table 1 Summary of meta-analysis estimates of effects, confidence intervals, and certainty of evidence
Relative effect odds ratio (95% CI)* | Anticipated absolute effect, per 1000 patients† (95% CI) | No. of participants (studies) | Certainty of evidence | Number needed to treat (95% CI) | |||
|---|---|---|---|---|---|---|---|
Progestogen | Placebo/no treatment | Difference | |||||
Maternal outcome | |||||||
Pre-eclampsia | 0.64 (0.42, 0.98) | 14 | 22 | 8 fewer (15 fewer to 1 fewer) | 3982 (3 RCTs) | ⊕ ⊕ ⊕○, moderate4 | 125 (67 to 1000) |
Gestational diabetes mellitus | 1.02 (0.79, 1.32) | 61 | 58 | 3 more (12 fewer to 16 more) | 3438 (2 RCTs) | ⊕ ⊕ ○○, low1, 4 | Not calculated (non-statistically significant) |
Placenta previa | 0.67 (0.32, 1.39) | 6 | 8 | 2 fewer (7 fewer to 2 more) | 3590 (3 RCTs) | ⊕○○○, vey low1, 2, 4 | Not calculated (non-statistically significant) |
Placental abruption | 0.58 (0.30, 1.13) | 7 | 12 | 5 fewer (10 fewer to 1 more) | 3219 (2 RCTs) | ⊕○○○, very low1, 2, 3, 4 | Not calculated (non-statistically significant) |
Perinatal outcome | |||||||
Preterm birth | 1.02 (0.86, 1.20) | 113 | 107 | 4 more (14 fewer to 15 more) | 4782 (9 RCTs) | ⊕ ⊕ ○○, low3, 4 | Not calculated (non-statistically significant) |
Low birth weight | 0.57 (0.34, 0.95) | 52 | 81 | 29 fewer (53 fewer to 1 fewer) | 935 (4 RCTs) | ⊕ ⊕ ⊕○, moderate4 | 34 (19 to 1000) |
Small for gestational age | 0.86 (0.58, 1.27) | 52 | 58 | 6 fewer (29 fewer to 9 more) | 4145 (4 RCTs) | ⊕○○○, very low1, 3, 4 | Not calculated (non-statistically significant) |
Perinatal mortality | 1.05 (0.58, 1.90) | 9 | 8 | 1 more (2 fewer to 5 more) | 4632 (7 RCTs) | ⊕○○○, very low1, 2, 3, 4 | Not calculated (non-statistically significant) |