| Autor: |
Quinn, Mary K, Smith, Emily R, Williams, Paige L, Urassa, Willy, Shi, Joy, Msamanga, Gernard, Fawzi, Wafaie W, Sudfeld, Christopher R |
| Předmět: |
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| Zdroj: |
Journal of Nutrition; Feb2020, Vol. 150 Issue 2, p356-363, 8p |
| Abstrakt: |
Background: Maternal micronutrient supplementation in pregnancy (MMS) has been shown to improve birth weight among infants in low- and middle-income countries. Recent evidence suggests that the survival benefits of MMS are greater for female infants compared to male infants, but the mechanisms leading to differential effects remain unclear.Objective: The objective of this study was to examine the potential mechanisms through which MMS acts on infant mortality among Tanzanian infants.Methods: We used data collected from pregnant women and newborns in a randomized, double-blind, placebo-controlled trial of MMS conducted in Tanzania to examine mediators of the effect of MMS on 6-wk infant mortality (NCT00197548). Causal mediation analyses with the counterfactual approach were conducted to assess the contributions of MMS on survival via their effects on birth weight, gestational age, weight-for-gestational age, and the joint effect of gestational age and weight-for-gestational age. The weighting method allowed for interaction between gestational age and weight-for-gestational age.Results: Among 7486 newborns, the effect of MMS on 6-wk survival was fully mediated (100%) through the joint effect of gestational age and weight-for-gestational age. MMS was also found to have a significant natural indirect effect through increased birth weight (P-value < 0.001) that explained 75% of the total effect on 6-wk mortality. When analyses were stratified by sex, changes in gestational age and weight-for-gestational age fully mediated the mortality effect among female infants (n = 3570), but these mediators only explained 34% of the effect among males (n = 3833).Conclusions: The potential sex-specific effects of MMS on mortality may be a result of differences in mechanisms related to birth outcomes. In the context of the Tanzanian trial, the observed effect of MMS on 6-wk mortality for female infants was entirely mediated by increased gestation duration and improved intrauterine growth, while these mechanisms did not appear to be major contributors among male infants. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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