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 4. Subgroup analysis and meta-regression for the effect of maternal micronutrient supplements on the risk of low birth weight 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 | 0.08 | 22% (0.22) | 46 | ||
| < 20 weeks | 9 | 0.92 (0.85–0.99) | – | – | – |
| ≥ 20 weeks | 6 | 0.76 (0.64–0.89) | – | – | – |
| No maternal education | 0.12 | 12% (0.32) | 33 | ||
| < 50% | 9 | 0.83 (0.76–0.91) | – | – | – |
| ≥ 50% | 4 | 0.95 (0.87–1.05) | – | – | – |
| Iron dose in treatment and control groups | 0.66 | 41% (0.05) | 0 | ||
| Same | 7 | 0.86 (0.75–0.99) | – | – | – |
| Different | 8 | 0.87 (0.80–0.95) | – | – | – |
| Maternal underweighta | 0.96 | 41% (0.05) | 0 | ||
| < 20% | 11 | 0.86 (0.80–0.92) | – | – | – |
| ≥ 20% | 4 | 0.79 (0.61–1.02) | – | – | – |
| Average maternal height | 0.44 | 41% (0.05) | 0 | ||
| < 155 cm | 7 | 0.91 (0.82–1.00) | – | – | – |
| ≥ 155 cm | 8 | 0.79 (0.69–0.91) | – | – | – |
| Primiparas | 0.70 | 41% (0.05) | 0 | ||
| < 35% | 8 | 0.83 (0.72–0.96) | – | – | – |
| ≥ 35% | 7 | 0.85 (0.77–0.92) | – | – | – |
CI, confidence interval; RR, relative risk.
a Body mass index (weight in kg divided by square of height in metres) < 18.5.