Summary of findings for the main comparison. Effects of giving vitamin A supplements to HIV‐positive women during pregnancy or after delivery.
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Population: HIV‐positive women during pregnancy and immediate postpartum period
Settings: any setting
Intervention: vitamin A supplements Comparison: placebo or no intervention | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | Number of participants (trials) | Certainty of the evidence (GRADE) | Comments | |
| Assumed risk with no vitamin A | Corresponding risk with vitamin A supplements | |||||
| HIV infection status of the child | 27 per 100 | 29 per 100 (24 to 34) | RR 1.07 (0.91 to 1.26) |
4428 (5 trials) | ⊕⊕⊕⊝
moderate1 due to imprecision |
Vitamin A supplements probably have little or no effect on mother‐to‐child transmission of HIV. |
| Mean birthweight | 2964 g | 34 g higher (13 g lower to 81 g higher) | MD 34.12 (−12.79 to 81.02) |
2181 (3 trials) | ⊕⊕⊝⊝
low2 due to imprecision |
Vitamin A supplements may increase the mean birthweight |
| Low birthweight | 17 per 100 | 13 per 100 (11 to 17) | RR 0.78 (0.63 to 0.97) | 1819 (3 trials) | ⊕⊕⊕⊝
moderate3 due to imprecision |
Vitamin A supplements probably reduce the incidence of low birthweight babies. |
| Child death by two years of age | 14 per 100 | 15 per 100 (13 to 18) | RR 1.06 (0.92 to 1.22) | 3883 (3 trials) | ⊕⊕⊝⊝
low2 due to imprecision |
Vitamin A supplements may have little or no effect on child death by two years of age. |
| Preterm delivery | 20 per 100 | 17 per 100 (10 to 28) | RR 0.84 (0.52 to 1.37) | 1577 (2 trials) | ⊕⊝⊝⊝
very low2,4 due to imprecision and selective reporting |
It is uncertain whether or not vitamin A supplements have an effect on preterm deliveries. |
| Stillbirth | 3 per 100 | 3 per 100 (2 to 5) | RR 1.13 (0.72 to 1.77) | 2335 (3 trials) | ⊕⊝⊝⊝
very low2,4 due to imprecision and selective reporting |
It is uncertain whether or not vitamin A supplements have an effect on stillbirths. |
| Maternal death | 3 per 100 | 2 per 100 (1 to 4) | RR 0.71 (0.35 to 1.43) | 1267 (2 trials) | ⊕⊝⊝⊝
very low2,4 due to imprecision and selective reporting |
It is uncertain whether or not vitamin A supplements have an effect on maternal deaths. |
| *The basis for the assumed risk is the mean control group risk across studies. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). Abbreviations: CI: confidence interval; g: gram; MD: mean difference; RR: risk ratio. | ||||||
| GRADE Working Group grades of evidence High certainty: further research is very unlikely to change our confidence in the estimate of effect. Moderate certainty: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low certainty: 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 certainty: we are very uncertain about the estimate. | ||||||
1We downgraded by 1 for imprecision, as the CI ranges from small benefits to a clinically important increase in harm. 2We downgraded by 2 for imprecision, as the CI ranges from clinically important benefits to a substantial increase in harm. 3We downgraded by 1 for imprecision, as the CI ranges from substantial benefits to no effect. 4We downgraded by 1 for possibility of selective reporting, because 1 or more eligible studies did not report this outcome.