# 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 I^{2} after adjusting for covariate (P-value) |
Reduction in I^{2} 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 underweight^{a} |
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.