Multiple micronutrient supplementation during pregnancy does not lead to greater infant birth size than does iron-only supplementation: a randomized controlled trial in a semirural community in Mexico.
What this study found
Multiple micronutrient supplementation did not improve infant birth size compared with iron-only supplementation. Adjusted differences were small and not significant for birth weight, 16.1 ± 31 g (P = 0.60), birth length, -0.002 ± 0.151 cm (P = 0.99), and ponderal index, 0.014 ± 0.018 kg/cm3 (P = 0.42). The adjusted odds ratios also showed no benefit for low birth weight, 0.98 (95% CI: 0.55, 1.74), intrauterine growth restriction, 0.82 (95% CI: 0.49, 1.39), intrauterine small size, 0.96 (95% CI: 0.59, 1.57), or preterm delivery, 1.16 (95% CI: 0.60, 2.23). Mean birth weight was 2.981 ± 0.391…
- Study & population
- Randomized controlled trial in pregnant women from a semirural community near Cuernavaca, Morelos, Mexico, recruited before 13 weeks of gestation and followed through delivery.
- Intervention
- Pregnant women in the active arm received a multiple micronutrient tablet containing vitamins A, D3, E, B1, B2, niacin, folic acid, B6, B12, C, zinc, iron, and magnesium.
- Key limitation
- There was substantial attrition before birth outcome analysis, with about one quarter of each arm lost to follow-up.
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Open PDFOriginal abstract
BACKGROUND Little is known about the benefits of prenatal multivitamin and mineral supplements in reducing low birth weight. OBJECTIVE We conducted a randomized, double-blind clinical trial in semirural Mexico to compare the effects of multiple micronutrient (MM) supplements with those of iron supplements during pregnancy on birth size. DESIGN Pregnant women (n = 873) were recruited before 13 wk of gestation and received supplements 6 d/wk at home, as well as routine antenatal care, until delivery. Both supplements contained 60 mg Fe, but the MM group also received 1-1.5 times the recommended dietary allowances of several micronutrients. RESULTS At recruitment, the women in the 2 groups were not significantly different in age, parity, economic status, height, or hemoglobin concentration but differed significantly in marital status (4.6% and 2.0% of women in the MM and iron-only groups, respectively, were single mothers) and mean (+/- SD) body mass index (in kg/m(2); 24.6 +/- 4.3 and 23.8 +/- 3.9 in the iron-only and MM groups, respectively). Losses to follow-up (25%) and compliance (95%) did not differ significantly between the groups. In intent-to-treat analyses (MM group: n = 323; iron-only group: n = 322), mean (+/- SD) birth weight (2.981 +/- 0.391 and 2.977 +/- 0.393 kg in the MM and iron-only groups, respectively) and birth length (48.61 +/- 1.82 and 48.66 +/- 1.83 cm in the MM and iron-only groups, respectively) did not differ significantly between the groups. CONCLUSION These findings suggest that MM supplementation during pregnancy does not lead to greater infant birth size than does iron-only supplementation.