Maternal multiple micronutrient supplementation and pregnancy outcomes in developing countries: meta-analysis and meta-regression

• Published in: Bulletin of the World Health Organization Vol. 89; no. 6; pp. 402 - 411
• Main Authors: KAWAI, Kosuke, SPIEGELMAN, Donna, SHANKAR, Anuraj H, FAWZI, Wafaie W
• Format: Journal Article
• Language: English; Portuguese
• Published: Genève Organisation mondiale de la santé 01.06.2011; World Health Organization; The World Health Organization
• Subjects: Acids; Biological and medical sciences; Birth weight; Clinical trials; Confidence Intervals; Developing Countries; Dietary Supplements; Education; Female; Folic Acid - therapeutic use; General aspects; Gestational age; Health Policy & Services; HIV; Human immunodeficiency virus; Humans; Industrialized nations; Infant mortality; Infant, Low Birth Weight; Infant, Newborn; Iron; Iron, Dietary - therapeutic use; LDCs; Medical sciences; Medical Subject Headings-MeSH; Meta-analysis; Micronutrients - physiology; Miscellaneous; Mortality; Physical growth; Pregnancy; Pregnancy Outcome; Prenatal Nutritional Physiological Phenomena; Public health. Hygiene; Public health. Hygiene-occupational medicine; Regression Analysis; Risk; Statistics as Topic; Systematic review; Vitamin B; Vitamin B Complex - therapeutic use; Womens health; Prognosis; Evidence-based practice; Developing countries; Regression analysis; Evidence-based medicine; Metaanalysis; Micronutrient; Multiple pregnancy; Mother; Evolution; Tropical medicine; Supplementation; Public health; WHO
• ISSN: 0042-9686; 1564-0604
• DOI: 10.2471/BLT.10.083758

To systematically review randomized controlled trials comparing the effect of supplementation with multiple micronutrients versus iron and folic acid on pregnancy outcomes in developing countries. MEDLINE and EMBASE were searched. Outcomes of interest were birth weight, low birth weight, small size for gestational age, perinatal mortality and neonatal mortality. Pooled relative risks (RRs) were estimated by random effects models. Sources of heterogeneity were explored through subgroup meta-analyses and meta-regression. Multiple micronutrient supplementation was more effective than iron and folic acid supplementation at reducing the risk of low birth weight (RR: 0.86, 95% confidence interval, CI: 0.79-0.93) and of small size for gestational age (RR: 0.85; 95% CI: 0.78-0.93). Micronutrient supplementation had no overall effect on perinatal mortality (RR: 1.05; 95% CI: 0.90-1.22), although substantial heterogeneity was evident (I(2) = 58%; P for heterogeneity = 0.008). Subgroup and meta-regression analyses suggested that micronutrient supplementation was associated with a lower risk of perinatal mortality in trials in which > 50% of mothers had formal education (RR: 0.93; 95% CI: 0.82-1.06) or in which supplementation was initiated after a mean of 20 weeks of gestation (RR: 0.88; 95% CI: 0.80-0.97). Maternal education or gestational age at initiation of supplementation may have contributed to the observed heterogeneous effects on perinatal mortality. The safety, efficacy and effective delivery of maternal micronutrient supplementation require further research.