Early childhood linear growth faltering in low- and middle-income countries

Abstract

Globally 149 million children under five are estimated to be stunted (length more than 2 standard deviations below international growth standards). Stunting, a form of linear growth failure, increases risk of illness, impaired cognitive development, and mortality. Global stunting estimates rely on cross-sectional surveys, which cannot provide direct information about the timing of onset or persistence of growth failure- a key consideration for defining critical windows to deliver preventive interventions. We performed the largest pooled analysis of longitudinal studies in low- and middle-income countries to date (n=31 cohorts, 62,993 children, ages 0-24 months), allowing us to identify the typical age of linear growth failure onset and to investigate recurrent faltering in early life. The highest incidence of stunting onset occurred from birth to age 3 months. From 0 to 15 months, less than 5% of children per month reversed their stunting status, and among those who did, stunting relapse was common. Early timing and low reversal rates emphasize the importance of preventive intervention delivery within the prenatal and early postnatal phases coupled with continued delivery of postnatal interventions through the first 1000 days of life.

Causes and consequences of child growth faltering in low- and middle-income countries

“…Maternal anthropometric status strongly influenced birth size, but the parallel drop in postnatal Z-scores among children born to different maternal phenotypes was much larger than differences at birth, indicating that growth trajectories were not fully “programmed” at birth (Fig 3a-c). Wasting and stunting incidence was highest before age 6 months, but mean LAZ decreased until age 18 months, 29 the dangerous concurrence of wasting and stunting peaked at age 18 months, 30 and large, seasonally driven declines in WLZ were observed across all ages. 30 Targeting postnatal interventions by season or by population subgroups defined by sex, socioeconomic status, maternal, and child birth characteristics identified herein should help focus preventive interventions to reduce the substantial, persistent burden of postnatal growth failure.…”

“…43,47–49 Concurrent wasting and stunting was measured at 18 months because stunting prevalence peaked at 18 months and the largest number of children were measured at 18 months across cohorts. 29 All measures of early growth failure were significantly associated with later, more serious growth failure, with measures of ponderal growth failure amongst the strongest predictors (Fig 4c).…”

“…We documented high incidence rates of wasting and stunting from birth to age 6 months. 29,30 Individual studies have suggested that early wasting could predispose children to later linear growth failure. 43–46 We hypothesized that early wasting could contribute to subsequent linear growth restriction, and early growth failure could be consequential for persistent growth failure and mortality during the first 24 months of life.…”

“…In companion articles, we report that the highest rates of incident stunting and wasting occur by age 3 months. 29,30 Behaviours associated with higher risk of stunting or wasting could be targeted by future interventions, and interventions could be optimized to encourage behaviour change before the age at which growth failure occurs. Characteristics associated with higher risk could also be used to identify children at risk of growth failure who might benefit most from preventative interventions.…”

Child wasting and concurrent stunting in low- and middle-income countries

“…24 A more complete understanding of the epidemiology of wasting and how it varies by age is key to develop and target preventive interventions. 11,25,[26][27][28] Unlike the cumulative process of linear growth failure leading to stunting, 29 wasting varies considerably over time both within-individuals and within-populations. 16,30 This dynamic nature means that the number of wasting episodes within a year is poorly captured in cross-sectional, survey-based estimates of wasting: as many as 13 times the number of children who are wasted at one point in time (prevalence) may experience a period of being wasted within a year (incidence).…”