Summary of findings 2. Any intermittent iron regimen (with or without other vitamins and minerals) compared with daily regimen (with same vitamins and minerals)‐maternal outcomes.
| Any intermittent iron regimen (with or without other vitamins and minerals) compared with daily regimen (with same vitamins and minerals)‐ maternal outcomes | ||||||
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Patient or population: Women receiving supplements in pregnancy
Settings: Community settings
Intervention: Any intermittent iron regimen (with or without other vitamins and minerals) Comparison: Daily regimen (with same vitamins and minerals) | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Daily regimen (with same vitamins and minerals) | Any intermittent iron regimen (with or without other vitamins and minerals) | |||||
| Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more) | Study population | RR 1.22 (0.84 to 1.80) | 676 (4 RCTs) | ⊕⊝⊝⊝ VERY LOW 1,2 | ||
| 169 per 1000 | 206 per 1000 (142 to 304) | |||||
| Moderate | ||||||
| 162 per 1000 | 198 per 1000 (136 to 292) | |||||
| Maternal iron deficiency at term (based on any indicator of iron status at 37 weeks' gestation or more) | Study population | (0 studies) | Not reported | |||
| 0 per 1000 | 0 per 1000 (0 to 0) | |||||
| Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least 1 additional laboratory indicators at 37 weeks' gestation or more) | Study population | RR 0.71 (0.08 to 6.63) | 156 (1 RCT) | ⊕⊝⊝⊝ VERY LOW 3,4 | ||
| 28 per 1000 | 20 per 1000 (2 to 188) | |||||
| Maternal death (death while pregnant or within 42 days of termination of pregnancy) | Study population | RR 0 (0 to 0) | 00 (0 study) | Not reported | ||
| 0 per 1000 | 0 per 1000 (0 to 0) | |||||
| Side effects (any reported throughout intervention period) | Study population | RR 0.56 (0.37 to 0.84) | 1777 (11 RCTs) | ⊕⊝⊝⊝ VERY LOW 1,5 | ||
| 330 per 1000 | 185 per 1000 (122 to 277) | |||||
| Moderate | ||||||
| 400 per 1000 | 224 per 1000 (148 to 336) | |||||
| Severe anaemia at any time during second and third trimester (Hb less than 70 g/L) | Study population | 1240 (6 RCTs) | ⊕⊝⊝⊝ VERY LOW 1,6 | No events | ||
| 0 per 1000 | 0 per 1000 (0 to 0) | |||||
| Maternal clinical malaria or other infection in pregnancy | Study population | RR 0 (0 to 0) | 00 (0 study) | Not reported | ||
| 0 per 1000 | 0 per 1000 (0 to 0) | |||||
| *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. | ||||||
1Studies contributing data had serious design limitations
2Wide 95% CI crossing the line of no effect
3Single study contributing data had design limitations
4Wide 95% CI crossing the line of no effect and few events
5High heterogeneity I² > 80%
6No events