Maternal multiple micronutrient supplementation and pregnancy outcomes in developing countries: meta-analysis and meta-regression
Kosuke Kawai, Donna Spiegelman, Anuraj H Shankar & Wafaie W Fawzi
Volume 89, Number 6, June 2011, 402-411B
Table 7. Results of subgroup analysis and meta-regression for the effect of maternal micronutrient supplementation on perinatal mortality in randomized controlled trials conducted in developing countries
| Characteristic | No. of trials | Pooled RR (95% CI) | Univariate meta-regression |
||
|---|---|---|---|---|---|
| P-value for test for heterogeneity by covariate | Residual I2 after adjusting for covariate (P-value) | Reduction in I2 after adjusting for covariate (%) | |||
| Average gestational age at initiation of supplements | 0.003 | 0% (0.49) | 100 | ||
| < 20 wk | 7 | 1.28 (1.10–1.49) | – | – | – |
| ≥ 20 wk | 4 | 0.88 (0.80–0.97) | – | – | – |
| No maternal education | 0.009 | 17% (0.31) | 71 | ||
| < 50% | 8 | 0.93 (0.82–1.06) | – | – | – |
| ≥ 50% | 3 | 1.41 (1.14–1.75) | – | – | – |
| Iron dose in treatment and control groups | 0.19 | 47% (0.05) | 19 | ||
| Same | 5 | 0.94 (0.79–1.12) | – | – | – |
| Different | 6 | 1.18 (0.95–1.47) | – | – | – |
| Maternal underweighta | 0.36 | 55% (0.01) | 5 | ||
| < 20% | 8 | 1.00 (0.84–1.19) | – | – | – |
| ≥ 20% | 3 | 1.22 (0.97–1.54) | – | – | – |
| Average maternal height | 0.90 | 58% (0.008) | 0 | ||
| < 155 cm | 6 | 1.09 (0.89–1.34) | – | – | – |
| ≥ 155 cm | 5 | 1.00 (0.75–1.33) | – | – | – |
| Primiparas | 0.91 | 58% (0.008) | 0 | ||
| < 35% | 6 | 1.10 (0.85–1.44) | – | – | – |
| ≥ 35% | 5 | 0.97 (0.83–1.14) | – | – | – |
| Effect of supplementation on risk of LGA | 0.86 | 56% (0.02) | 0 | ||
| < 10% (RR < 1.10) | 4 | 1.19 (0.92–1.54) | – | – | – |
| ≥ 10% (RR ≥ 1.10) | 5 | 1.06 (0.81–1.38) | – | – | – |
| Effect of supplementation on birth weight (mean difference) | 0.34 | 58% (0.008) | 0 | ||
| ≥ 50 g | 5 | 0.96 (0.76–1.22) | – | – | – |
| < 50 g | 6 | 1.14 (0.90–1.44) | – | – | – |
CI, confidence interval; LGA, large size for gestational age; RR, relative risk.
a Body mass index (weight in kg divided by square of height in metres) < 18.5.