Risk of childhood undernutrition related to small-for-gestational age and preterm birth in low- and middle-income countries

Abstract

Background: Low- and middle-income countries continue to experience a large burden of stunting; 148 million children were estimated to be stunted, around 30-40% of all children in 2011. In many of these countries, foetal growth restriction (FGR) is common, as is subsequent growth faltering in the first 2 years. Although there is agreement that stunting involves both prenatal and postnatal growth failure, the extent to which FGR contributes to stunting and other indicators of nutritional status is uncertain.

Methods: Using extant longitudinal birth cohorts (n=19) with data on birthweight, gestational age and child anthropometry (12-60 months), we estimated study-specific and pooled risk estimates of stunting, wasting and underweight by small-for-gestational age (SGA) and preterm birth.

Results: We grouped children according to four combinations of SGA and gestational age: adequate size-for-gestational age (AGA) and preterm; SGA and term; SGA and preterm; and AGA and term (the reference group). Relative to AGA and term, the OR (95% confidence interval) for stunting associated with AGA and preterm, SGA and term, and SGA and preterm was 1.93 (1.71, 2.18), 2.43 (2.22, 2.66) and 4.51 (3.42, 5.93), respectively. A similar magnitude of risk was also observed for wasting and underweight. Low birthweight was associated with 2.5-3.5-fold higher odds of wasting, stunting and underweight. The population attributable risk for overall SGA for outcomes of childhood stunting and wasting was 20% and 30%, respectively.

Conclusions: This analysis estimates that childhood undernutrition may have its origins in the foetal period, suggesting a need to intervene early, ideally during pregnancy, with interventions known to reduce FGR and preterm birth.

Keywords: Foetal growth restriction; childhood; preterm birth; stunting; wasting.

Figure 1

Flow diagram of literature search for cohorts

Figure 2

Regional and LMIC odds ratios for childhood stunting at 12 to 60 months of age by size for gestational age and preterm birth. Reference group is children born AGA and term; LMIC, low- and middle-income countries

Figure 3

Random-effects model forest plot of odds ratios for childhood stunting at 12 to 60 months by birthweight categories in children born SGA and term. Reference group is children born AGA and term. Includes 10 cohorts, using data provided to CHERG working group

Figure 4

Random-effects model forest plot of odds ratios for childhood stunting at 12 to 60 months by gestational age categories in children born AGA and preterm. Reference group is children born AGA and term