Childhood stunting in relation to the pre- and postnatal environment during the first 2 years of life: the MAL-ED longitudinal birth cohort study

Background: stunting is the most prevalent manifestation of childhood malnutrition. to characterize factors that contribute to stunting in resource-poor settings,we studied a priori selected biological and social factors collected longitudinally in a cohort of newborns. methods and findings: we enrolled 1,868 children across 7 resource-poor settings in bangladesh,brazil,india,nepal,peru,south africa,and tanzania shortly after birth and followed them for 24 months between 2 november 2009 and 28 february 2014. we collected longitudinal anthropometry,sociodemographic factors,maternal-reported illnesses,and antibiotic use; child feeding practices; dietary intake starting at 9 months; and longitudinal blood,urine,and stool samples to investigate non-diarrheal enteropathogens,micronutrients,gut inflammation and permeability,and systemic inflammation. we categorized length-for-age z-scores into 3 groups (not stunted,≥−1; at risk,<−1 to −2; and stunted,<−2),and used multivariable ordinal logistic regression to model the cumulative odds of being in a lower length-for-age category (at risk or stunted). a total of 1,197 children with complete longitudinal data were available for analysis. the prevalence of having a length-for-age z-score below −1 increased from 43% (range 37%–47% across sites) shortly after birth (mean 7.7 days post-delivery,range 0 to 17 days) to 74% (16%–96%) at 24 months. the prevalence of stunting increased 3-fold during this same time period. factors that contributed to the odds of being in a lower length-for-age category at 24 months were lower enrollment weight-for-age (interquartile cumulative odds ratio = 1.82,95% ci 1.49–2.23),shorter maternal height (2.38,1.89–3.01),higher number of enteropathogens in non-diarrheal stools (1.36,1.07–1.73),lower socioeconomic status (1.75,1.20–2.55),and lower percent of energy from protein (1.39,1.13–1.72). site-specific analyses suggest that reported associations were similar across settings. while loss to follow-up and missing data are inevitable,some study sites had greater loss to follow-up and more missing data than others,which may limit the generalizability of the findings. conclusions: neonatal and maternal factors were early determinants of lower length-for-age,and their contribution remained important throughout the first 24 months of life,whereas the average number of enteropathogens in non-diarrheal stools,socioeconomic status,and dietary intake became increasingly important contributors by 24 months relative to neonatal and maternal factors. © 2017 public library of science. all rights reserved.