Parental childhood growth and offspring birthweight: pooled analyses from four birth cohorts in low and middle income countries

Local contextual factors of child stunting found via shared values of stakeholder groups: an exploratory case study in Kaffrine, Senegal

OBJECTIVE

This work aims to demonstrate an original approach to identify links between locally situated shared values and contextual factors of stunting. Stunting results from multi-factorial and multi-sectoral determinants, but interventions typically neglect locally situated lived experiences, which contributes to problematic designs that are not meaningful for those concerned and/or relatively ineffective.

DESIGN

This case study investigates relevant contextual factors in two steps: by first facilitating local stakeholder groups (n 11) to crystallise their shared-values-in-action using a specialised method from sustainability studies (WeValue_InSitu (WVIS)). Secondly, participants (n 44) have focus group discussions (FGD) about everyday practices around child feeding/food systems, education and/or family life. Because the first step strongly grounds participants in local shared values, the FGD can reveal deep links between contextual factors and potential influences on stunting.

SETTING

Kaffrine, Senegal, an 'Action Against Stunting Hub' site. December 2020.

PARTICIPANTS

Eleven stakeholder groups of mothers, fathers, grandmothers, pre-school teachers, community health workers, farmers, market traders and public administrators.

RESULTS

Local contextual factors of stunting were identified, including traditional beliefs concerning eating and growing practices; fathers as decision-makers; health worker trust; financial non-autonomy for women; insufficient water for preferred crops; merchants' non-access to quality produce; religious teachings and social structures affecting children's food environment.

CONCLUSIONS

Local contextual factors were identified. Pre-knowledge of these could significantly improve effectiveness of intervention designs locally, with possible applicability at other sites. The WVIS approach proved efficient and useful for making tangible contextual factors and their potential links to stunting, via a lens of local shared values, showing general promise for intervention research.

Maternal Employment and Child Malnutrition in Ecuador

BACKGROUND

This paper estimates the causal impact of maternal employment on childhood malnutrition status in Ecuador to understand the trade-off between the time mothers devote to work and the time they dedicate to child-caring activities.

METHODS

We use the instrumental variables (IV) approach and exogenous cantonal variation in maternal labor market conditions to account for the potential endogeneity of mothers' employment. The analysis employs the Ecuadorian National Health and Nutrition Survey 2018 and the Living Conditions Survey 2014.

RESULTS

The IV estimations indicate that maternal employment increases the probability of having stunted children by between 4.2 and 18.1 percent, while no significant effect is found in the case of children suffering from wasting, being underweight, or being overweight. The effect of maternal employment on stunting is stronger among mothers with high education and living in high-income households. Inconclusive effects of mothers' overweight status are reported. The results are robust to several robustness checks.

CONCLUSIONS

Overall, our findings suggest that the additional income that a working mother may obtain (the income effect) does not offset the loss of time available for direct childcare (the time constraint) in terms of child health status, and this effect is even more apparent for more affluent and more educated mothers. Government interventions, including effective conditional cash transfers and/or in-kind family policies, intended to reduce the cost of raising children among vulnerable families appear to be aligned with our findings.

Intergenerational transmission of birth weight: a systematic review and meta-analysis

The objectives of this study were (1) to systematically review the literature on the association between birth weight in children born in the first and second generation and (2) to quantify this association by performing a meta-analysis. A systematic review was carried out in six databases (PubMed, Science Direct, Web of Science, Embase, Scopus, CINAHL and LILACS), in January 2021, for studies that recorded the birth weight of parents and children. A meta-analysis using random effects to obtain a pooled effect of the difference in birth weight and the association of low birth weight (LBW) between generations was performed. Furthermore, univariable meta-regression was conducted to assess heterogeneity. Egger's tests were used to possible publication biases. Of the 9878 identified studies, seventy were read in full and twenty were included in the meta-analysis (ten prospective cohorts and ten retrospective cohorts), fourteen studies for difference in means and eleven studies for the association of LBW between generations (twenty-three estimates). Across all studies, there was no statistically significant mean difference (MD) birth weight between first and second generation (MD 19·26, 95 % CI 28·85, 67·36; P = 0·43). Overall, children of LBW parents were 69 % more likely to have LBW (pooled effect size 1·69, 95 % CI (1·46, 1·95); I2:85·8 %). No source of heterogeneity was identified among the studies and no publication bias. The average birth weight of parents does not influence the average birth weight of children; however, the proportion of LBW among the parents seems to affect the offspring's birth weight.

Elucidating the sustained decline in under-three child linear growth faltering in Nepal, 1996-2016

Childhood linear growth faltering remains a major public health concern in Nepal. Nevertheless, over the past 20 years, Nepal sustained one of the most rapid reductions in the prevalence of stunting worldwide. First, our study analysed the trends in height-for-age z-score (HAZ), stunting prevalence, and available nutrition-sensitive and nutrition-specific determinants of linear growth faltering in under-three children across Nepal's Family Health Survey 1996 and Nepal's Demographic and Health Surveys 2001, 2006, 2011, and 2016. Second, we constructed pooled multivariable linear regression models and decomposed the contributions of our time-variant determinants on the predicted changes in HAZ and stunting over the past two decades. Our findings indicate substantial improvements in HAZ (38.5%) and reductions in stunting (-42.6%) and severe stunting prevalence (-63.9%) in Nepalese children aged 0-35 months. We also report that the increment in HAZ, across the 1996-2016 period, was significantly associated (confounder-adjusted p < .05) with household asset index, maternal and paternal years of education, maternal body mass index and height, basic child vaccinations, preceding birth interval, childbirth in a medical facility, and prenatal doctor visits. Furthermore, our quantitative decomposition of HAZ identified advances in utilisation of health care and related services (31.7% of predicted change), household wealth accumulation (25%), parental education (21.7%), and maternal nutrition (8.3%) as key drivers of the long-term and sustained progress against child linear growth deficits. Our research reiterates the multifactorial nature of chronic child undernutrition and the need for coherent multisectoral nutrition-sensitive and nutrition-specific strategies at national scale to further improve linear growth in Nepal. [Correction added on 6 November 2020, after first online publication: in abstract, the citation year in the fourth sentence has been changed from '2001' to '2011'.].

Impact of Nutrition on the Next Generation: The INCAP Longitudinal Study

BACKGROUND

The design of the original nutrition supplementation trial that was conducted from 1969 to 1977 in 4 villages in rural Guatemala to evaluate the benefits of improving nutrition during pregnancy and early childhood, combined with several follow-up studies, provides unique data to examine the effects of improving nutrition on the next generation.

OBJECTIVE

This article provides a summary of the key findings from the INCAP Longitudinal Study on the intergenerational effects of improving nutrition on the growth and well-being of the next generation.

METHODS

The key outcomes include offspring birth size as well as attained size and body composition through age 11 years. The sample sizes varied from approximately 200 to 800 depending on the timing of the follow-up studies and data collection protocols. The effects of parental birth size, maternal linear growth from birth through adulthood, and exposure to the nutrition intervention, that is, Atole versus Fresco during critical periods from prenatal through age 15 years, have been examined using complex models and approaches.

RESULTS

Overall, these publications demonstrate clear improvements in the growth of the next generation. Effects were seen primarily for maternal exposure to Atole and were larger for boys compared to girls. Stunting during early childhood among girls was also a significant predictor of offspring birth size, and younger age at first pregnancy (<20 years) was associated with an increased risk of stunting in the offspring.

CONCLUSIONS

These studies have contributed significantly to our understanding of the importance of investing in nutrition, especially during early childhood for future generations.

Relative and absolute wealth mobility since birth in relation to health and human capital in middle adulthood: An analysis of a Guatemalan birth cohort

Background

Wealth mobility, as both relative (positional) and absolute (material) wealth acquisition, may counteract negative consequences of early life adversities on adult health.

Methods

We use longitudinal data (1967–2018) from the INCAP birth cohort, Guatemala (n = 1386). Using wealth as a measure of socio-economic position, we assess the association of life course relative mobility using latent class analysis and absolute material gains using conditional wealth measures. We estimate associations of wealth mobility with indicators of human capital, specifically height, weight status (BMI in kg/m²), psychological distress (WHO SRQ-20 score) and fluid intelligence (Ravens Progressive Matrices score; RPM) in middle adulthood.

Results

We identified four latent classes of relative mobility – Stable Low (n = 498), Stable High (n = 223), Downwardly Mobile (n = 201) and Upwardly Mobile (n = 464). Attained schooling (years) was positively associated with membership in Upwardly Mobile (odds ratio; 1.50, 95%CI: 1.31, 1.71) vs Stable Low, and inversely with membership in Downwardly Mobile (0.65, 95%CI: 0.54, 0.79) vs Stable High. Being Upwardly Mobile (vs Stable Low) was positively associated with height (1.88 cm, 95%CI: 1.04, 2.72), relative weight (1.32 kg/m², 95%CI: 0.57, 2.07), lower psychological distress (−0.82 units, 95%CI: 1.34, −0.29) and fluid intelligence (0.94 units, 95%CI: 0.28, 1.59). Being Downwardly Mobile (vs Stable High) was associated with lower fluid intelligence (−2.69 units, 95%CI: 3.69, −1.68), and higher psychological distress (1.15 units, 95%CI: 0.34, 1.95). Absolute wealth gains (z-scores) from early to middle adulthood were positively associated with relative weight (0.62 kg/m², 95%CI: 0.28, 0.96), lower psychological distress (−0.37 units, 95%CI: 0.60, −0.14) and fluid intelligence (0.50 units, 95%CI: 0.21, 0.79).

Conclusions

Higher attained schooling provided a pathway for upward relative mobility and higher absolute wealth gains as well as protection against downward relative mobility. Upward mobility was associated with lower psychological distress and higher fluid intelligence but also higher weight status.

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Early life wealth and educational attainment are associated with upward wealth mobility, both in relative and absolute terms.

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Upward relative mobility is associated with lower psychological distress, and higher fluid intelligence and BMI.

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Downward relative mobility is associated with lower fluid intelligence, lower height, and higher psychological distress.

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Wealth gains from early to middle adulthood were associated with higher BMI and intelligence and lower psychological distress.

Maternal Preconception Body Size and Early Childhood Growth during Prenatal and Postnatal Periods Are Positively Associated with Child-Attained Body Size at Age 6-7 Years: Results from a Follow-up of the PRECONCEPT Trial

BACKGROUND

Growth faltering is associated with adverse consequences during childhood and later life. However, questions remain on the relative importance of preconception maternal nutritional status (PMNS) and child growth during the first 1000 d of life.

OBJECTIVES

We examined associations between PMNS, gestational weight gain (GWG), and child growth during the first 1000 d with attained body size at age 6-7 y.

METHODS

We used data from a follow-up of a double-blinded randomized controlled trial of preconception micronutrient supplementation in Vietnam (n = 5011 women). The outcomes included offspring height-for-age z score (HAZ), BMI-for-age z score (BMIZ), and prevalence of stunting and overweight/obese at age 6-7 y (n = 1579). We used multivariable linear and Poisson regression models to evaluate the relative contributions of PMNS (height and BMI), GWG, and conditional growth in 4 periods: fetal, 0-6 mo, 6-12 mo, and 12-24 mo.

RESULTS

PMNS was positively associated with child-attained size at 6-7 y. For each 1-SD higher maternal height and BMI, offspring had 0.28-SD and 0.13-SD higher HAZ at 6-7 y, respectively. Higher maternal BMI and GWG were associated with larger child BMIZ (β: 0.29 and 0.10, respectively). Faster linear growth, especially from 6 to 24 mo, had the strongest association with child HAZ at 6-7 y (β: 0.39-0.42), whereas conditional weight measures in all periods were similarly associated with HAZ (β: 0.10-0.15). For BMIZ at 6-7 y, the magnitude of association was larger and increased with child age for conditional weight gain (β: 0.21-0.41) but smaller for conditional length gain. Faster growth in the first 2 y was associated with reduced risk of stunting and thinness but increased risk of overweight/obese at 6-7 y.

CONCLUSIONS

Interventions aimed at improving child growth while minimizing the risk of overweight during the school age years should target both women of reproductive age prior to conception through delivery and their offspring during the first 1000 d. The trial was registered at clinicaltrials.gov as NCT01665378.

The effect of maternal depressive symptoms on infant feeding practices in rural Ethiopia: community based birth cohort study

BACKGROUND

Maternal depression and other psychosocial factors have been shown to have adverse consequences on infant feeding practices. This study explored the longitudinal relationship of maternal depressive symptoms and other selected psychosocial factors with infant feeding practices (IFPs) in rural Ethiopia using summary IFP index.

METHODS

This study uses existing data from the ENGINE birth cohort study, conducted from March 2014 to March 2016 in three districts in the southwest of Ethiopia. A total of 4680 pregnant women were recruited and data were collected once during pregnancy (twice for those in the first trimester), at birth, and then every 3 months until the child was 12 months old. A standardized questionnaire was used to collect data on IFPs, maternal depressive symptoms, household food insecurity, intimate partner violence (IPV), maternal social support, active social participation, and other sociodemographic variables. A composite measure of IFP index was computed using 14 WHO recommended infant and young child feeding (IYCF) practice indicators. High IFP index indicated best practice. Prenatal and postnatal maternal depressive symptoms were assessed using the patient health questionnaire (PHQ-9). Linear multilevel mixed effects model was fitted to assess longitudinal relationship of IFPs with maternal depression and other psychosocial factors.

RESULTS

Reports of higher postnatal depressive symptoms (ß = - 1.03, P = 0.001) and IPV (ß = - 0.21, P = 0.001) were associated with lower scores on the IFP index. Whereas, reports of better maternal social support (ß = 0.11, P = 0.002) and active social participation (ß = 0.55, P < 0.001) were associated with higher scores on the IFP index. Contrary to expectations, moderate household food insecurity (ß = 0.84, P = 0.003), severe household food insecurity (ß = 1.03, P = 0.01) and infant morbidity episodes (ß = 0.63, P = 0.013) were associated with higher scores on the IFP index.

CONCLUSIONS

Overall, a multitude of factors are related to IFPs and hence coordinated, multi-sectoral and multi-stakeholder interventions including maternal depressive symptoms screening and management are needed to improve infant feeding practices.

Adolescent Cranial Volume as a Sensitive Marker of Parental Investment: The Role of Non-material Resources?

Growth of different body parts in humans is sensitive to different resource constraints that are mediated by parental investment. Parental investment can involve the expenditure of material, cognitive, and emotional resources on offspring. Cranial volume, an important predictor of cognitive ability, appears understudied in this context. We asked (1) whether there are associations between growth and family structure, self-reported estimates for resource availability, and sibling number; and (2) whether these constraints relate to head and body growth in a similar manner. We assessed the associations between parental investment, height, and cranial volume in a cross-sectional study of Estonian children (born 1980-87, aged 11-17). Height correlated negatively with the number of siblings but this association became negligible in a model controlling for birthweight, parental heights, and mother's age at birth. Unlike height, cranial volume was unrelated to sibling number, but it was negatively associated with self-reported meat and general resource shortage. Cranial volume was related to family structure and paternal education. Children living with both birth-parents had larger heads than those living in families containing a step-parent. Since these family types did not differ with respect to meat or general resource shortage, our findings suggest that families including both genetic parents provide non-material benefits that stimulate predominantly cranial growth. For the studied developmental period, cranial volume appeared a more sensitive marker of growth constraints than height. The potential of using cranial volume for quantifying physical impact of non-material parental investment deserves further attention.

Drivers of stunting reduction in Ethiopia: a country case study

BACKGROUND

Chronic undernutrition in children continues to be a global public health concern. Ethiopia has documented a significant decline in the prevalence of childhood stunting, a measure of chronic undernutrition, over the last 20 y.

OBJECTIVES

The aim of this research was to conduct a systematic assessment of the determinants that have driven child stunting reduction in Ethiopia from 2000 to 2016, focused on the national, community, household, and individual level.

METHODS

This study employed both quantitative and qualitative methods. Specifically, a systematic literature review, retrospective quantitative data analysis using Demographic and Health Surveys from 2000-2016, qualitative data collection and analysis, and analyses of key nutrition-specific and -sensitive policies and programs were undertaken.

RESULTS

National stunting prevalence improved from 51% in 2000 to 32% in 2016. Regional variations exist, as do pro-rich, pro-urban, and pro-educated inequalities. Child height-for-age z score (HAZ) decomposition explained >100% of predicted change in mean HAZ between 2000 and 2016, with key factors including increases in total consumable crop yield (32% of change), increased number of health workers (28%), reduction in open defecation (13%), parental education (10%), maternal nutrition (5%), economic improvement (4%), and reduced diarrhea incidence (4%). Policies and programs that were key to stunting decline focused on promoting rural agriculture to improve food security; decentralization of the health system, incorporating health extension workers to improve rural access to health services and reduce open defecation; multisectoral poverty reduction strategies; and a commitment to improving girls' education. Interviews with national and regional stakeholders and mothers in communities presented improvements in health service access, women and girls' education, improved agricultural production, and improved sanitation and child care practices as drivers of stunting reduction.

CONCLUSIONS

Ethiopia's stunting decline was driven by both nutrition-specific and -sensitive sectors, with particular focus on the agriculture sector, health care access, sanitation, and education.

Observed feeding behaviours and effects on child weight and length at 12 months of age: Findings from the SPRING cluster-randomized controlled trial in rural India

BACKGROUND

Child undernutrition results in poor growth in early childhood, undermines optimal development and increases the risk of mortality. Responsive feeding has been promoted as a key intervention for improving nutritional status, however measurement of this remains difficult and has rarely considered child behaviour. We therefore developed a new observed feeding tool to assess both child and caregiver behaviours, as well as their interaction during feeding, and investigate the effect of these on children anthropometric measures at 12-months of age in rural India.

METHODS

Our study was nested within the SPRING cluster-randomized controlled trial in Rewari, North India. Outcomes were children length-for-age (LAZ), weight-for-length (WLZ) and weight-for-age (WAZ) Z scores at 12 months of age, based on the WHO Child Growth standards. Trained non-specialists live-coded feeding episodes using the newly designed tool. Scores were then created using principal components analysis representing child behaviour, caregiver behaviour and caregiver-child interaction. Mixed effects linear regression was used to assess associations between feeding behaviours and anthropometric outcomes.

RESULTS

857 children had a meal observation and were included. Anthropometric status was poor (mean length-for-age -1.59 (SD = 1.11); mean weight-for-length -0.58 (0.95); mean weight-for-age -1.22 (1.04)). There were positive linear differences in weight-for-length per unit increase in caregiver responsive behaviours score (adjusted β-coeff = 0.006, 95%CI = (0.001, 0.011), p = 0.01), in length-for-age and weight-for-age per unit increase in child responsive behaviours score (respectively adjusted β-coeff = 0.004, 95%CI = (0.001, 0.007), p = 0.02, and adjusted β-coeff = 0.003, 95%CI = (0.00001, 0.006), p = 0.049), and in both weight-for-length and weight-for-age per unit increase in caregiver-child interaction score (respectively adjusted β-coeff = 0.007, 95%CI = (0.003, 0.012), p = 0.001, and adjusted β-coeff = 0.005, 95%CI = (0.001, 0.011), p = 0.01). No association was seen between child behaviours and weight-for-length, caregiver behaviours and length and caregiver-child interaction and length.

CONCLUSIONS

We found that trained non-specialists could assess feeding episodes using a newly designed checklist. Further, child and caregiver behaviours were associated with weight and length at only 12 months of age, a reminder of the importance of interventions to improve responsive feeding quality as we strive towards achievement of the sustainable development goals.

Development of Tanner Stage-Age Adjusted CDC Height Curves for Research and Clinical Applications

Background and Objective

Variations in normal pubertal development, pubertal disorders, and race/ethnicity can lead to differences in growth patterns and timing that are not captured by the Centers for Disease Control and Prevention (CDC) height-for-chronological age (CA_Height) charts. Therefore, we sought to develop new Tanner stage-adjusted height-for-age (TSA_Height) charts accounting for these differences.

Study Design

Population-based Tanner staging and anthropometric data for 13 358 children age 8 to 18 years from 3 large US national surveys: National Health Examination Surveys (NHES cycle III); the Hispanic Health and Nutrition Examination Surveys (HHANES) and the third National Health and Nutrition Examination Surveys (NHANES III) were analyzed. TSA_Height semi-parametric models with additive age splines were used to develop smoothed TSA_Height curves accounting for maturation stage and calendar age.

Results

As expected, the TSA_Height curves did not track along the respective percentile curves for the CDC 2000 CA_Height curves. We generated race/ethnicity-nonspecific and race/ethnicity-specific TSA_Height charts stratified by sex and plotted against the CDC 2000 CA_Height curves to account for the pubertal status differences between these models. An online calculator to adjust height for pubertal status was created.

Conclusions

TSA_Height charts provide a much-needed tool to assess and manage linear growth for US children over the course of puberty. These tools may be useful in clinical management of children with pubertal timing variations.

Intergenerational effect of early-life growth on offspring height: Evidence from the Hertfordshire Cohort Study

BACKGROUND

Previous intergenerational (parent to child) and transgenerational (grandparent to grandchild) studies have shown there is a link between parental and offspring birthweight.

OBJECTIVES

The aim was to explore the association between the early-life weight gain of an individual and the adult height of their children and grandchildren.

METHODS

Study participants across three generations of the Hertfordshire Cohort Study (HCS) were included in this study. Health visitors recorded the birthweight (kg) and weight at 1 year (kg) of the original (F0 generation) HCS participants when they were born in Hertfordshire between 1931 and 1939. A conditional infant weight gain score for F0 participants was calculated using birthweight and weight at 1 year, and self-reported height (cm) of their children (F1 generation) and their grandchildren (F2 generation) was obtained from postal questionnaires. Due to the lack of clustering within family lines, linear regression analysis was used to compare intergenerational relationships.

RESULTS

Data were available from 139 F0, 148 F1, and 198 F2 participants. A positive association was found between parental birthweight (F0) and offspring adult height; on average, a 1 kg increase in F0 birthweight was associated with a 2.04 cm increase in F1 adult height (beta 2.04, 95% confidence interval [CI] -0.03, 4.10). A positive association was found between F0 conditional weight gain during the first year of life and offspring (beta 1.53, 95% CI 0.45, 2.62) and grandchild height (beta 1.06, 95% CI 0.03, 2.10). Positive associations were also found between F0 weight at 1 year and offspring (beta 1.83, 95% CI 0.79, 2.87) and grandchild height (beta 0.91, 95% CI -0.10, 1.91).

CONCLUSION

This study demonstrates an association between grandparental weight gain in early life and the heights of their children and grandchildren. The results of these analyses highlight the importance of early-life weight gain on the adult stature of subsequent offspring.

Drivers of Under-Five Stunting Trend in 14 Low- and Middle-Income Countries since the Turn of the Millennium: A Multilevel Pooled Analysis of 50 Demographic and Health Surveys

BACKGROUND

Understanding the drivers contributing to the decreasing trend in stunting is paramount to meeting the World Health Assembly's global target of 40% stunting reduction by 2025.

METHODS

We pooled data from 50 Demographic and Health Surveys since 2000 in 14 countries to examine the relationships between the stunting trend and potential factors at distal, intermediate, and proximal levels. A multilevel pooled trend analysis was used to estimate the association between the change in potential drivers at a country level and stunting probability for an individual child while adjusting for time trends and child-level covariates. A four-level mixed-effects linear probability regression model was fitted, accounting for the clustering of data by sampling clusters, survey-rounds, and countries.

RESULTS

Stunting followed a decreasing trend in all countries at an average annual rate of 1.04 percentage points. Among the distal factors assessed, a decrease in the Gini coefficient, an improvement in women's decision-making, and an increase in urbanization were significantly associated with a lower probability of stunting within a country. Improvements in households' access to improved sanitation facilities and drinking water sources, and children's access to basic vaccinations were the important intermediate service-related drivers, whereas improvements in early initiation of breastfeeding and a decrease in the prevalence of low birthweight were the important proximal drivers.

CONCLUSIONS

The results reinforce the need for a combination of nutrition-sensitive and -specific interventions to tackle the problem of stunting. The identified drivers help to guide global efforts to further accelerate stunting reduction and monitor progress against chronic childhood undernutrition.

Drivers of Under-Five Stunting Trend in 14 Low- and Middle-Income Countries since the Turn of the Millennium: A Multilevel Pooled Analysis of 50 Demographic and Health Surveys

BACKGROUND

Understanding the drivers contributing to the decreasing trend in stunting is paramount to meeting the World Health Assembly's global target of 40% stunting reduction by 2025.

METHODS

We pooled data from 50 Demographic and Health Surveys since 2000 in 14 countries to examine the relationships between the stunting trend and potential factors at distal, intermediate, and proximal levels. A multilevel pooled trend analysis was used to estimate the association between the change in potential drivers at a country level and stunting probability for an individual child while adjusting for time trends and child-level covariates. A four-level mixed-effects linear probability regression model was fitted, accounting for the clustering of data by sampling clusters, survey-rounds, and countries.

RESULTS

Stunting followed a decreasing trend in all countries at an average annual rate of 1.04 percentage points. Among the distal factors assessed, a decrease in the Gini coefficient, an improvement in women's decision-making, and an increase in urbanization were significantly associated with a lower probability of stunting within a country. Improvements in households' access to improved sanitation facilities and drinking water sources, and children's access to basic vaccinations were the important intermediate service-related drivers, whereas improvements in early initiation of breastfeeding and a decrease in the prevalence of low birthweight were the important proximal drivers.

CONCLUSIONS

The results reinforce the need for a combination of nutrition-sensitive and -specific interventions to tackle the problem of stunting. The identified drivers help to guide global efforts to further accelerate stunting reduction and monitor progress against chronic childhood undernutrition.

Intergenerational transfer of health inequalities: exploration of mechanisms in the Birth to Twenty cohort in South Africa

South Africa’s history of colonialism and Apartheid contributed to its extreme levels of inequality. Twenty-five years after the transition to democracy, socio-economic and health inequalities continue to rank among the highest in the world. The Birth to Twenty+ study follows a cohort born in urban Johannesburg in 1990 through their early lives and into young adulthood. Also known as ‘Mandela’s Children’, these ‘children of the ‘90s’ were the first generation to be raised in a democratic society, whose elected government implemented policies to achieve greater socio-economic and health equality. Correlating early life outcomes to those of their parents provides a baseline estimate of intergenerational transmission of historical inequality. Analyses of their early life course indicates the potential breakdown in inequality in the first generation. This paper provides an overview of empirical results on intergenerational change in socio-economic status and health during South Africa’s political transition. Access to infrastructural services improved, and poverty reduced following the rapid expansion of unconditional cash transfers mainly to children and pensioners. However, unemployment remained high and job discrimination continued. Inequalities in health follow similar patterns, and progress did not equate to convergence. Some catch-up physical growth occurred—both across groups and over time—but not sufficient to bridge cognitive inequalities. Socio-economic and health inequalities continued as the children of the ‘90s reached young adulthood. Based on knowledge of other transitions, it is likely that these inequalities will only start to break down in later generations, provided social and economic progress holds steady.

What explains the fall in child stunting in Sub-Saharan Africa?

There have been steep falls in rates of child stunting in much of Sub-Saharan Africa (SSA). Using Demographic and Health Survey data, we document significant reductions in stunting in seven SSA countries in the period 2005–2014. For each country, we distinguish potential determinants that move in a direction consistent with having contributed to the reduction in stunting from those that do not. We then decompose the change in stunting and in proximal determinants into a part that can be explained by changes in distal determinants and a residual part that captures the impact of unmeasured factors, such as vertical nutrition programs. We show that increases in coverage of child immunization, deworming medication and maternal iron supplementation often coincide with a fall in stunting. The magnitudes and directions of changes in two other proximal determinants -- age-appropriate feeding and diarrhea prevalence -- suggest that these have not been strong contributors to the fall in stunting. Utilization of maternity care emerges from the decomposition analysis as the most important distal determinant associated with reduced stunting, and also with increased coverage of iron supplementation, and, to a lesser extent, with child immunization and deworming medication. This circumstantial evidence is strong enough to warrant more detailed investigation of the extent to which maternity care is an effective channel through which to target further attacks on the blight of undernourished children.

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The rate of children (<2 years old) who are stunted fell in many Sub-Saharan African countries in recent decades.

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This reduction was associated with improved access to maternity care.

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The improved access to maternity care may proxy for improvements in good quality preventive care.

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The reduction in stunting was not associated with improved feeding practices or reduced incidence of diseases.

Ethiopia's high childhood undernutrition explained: analysis of the prevalence and key correlates based on recent nationally representative data

OBJECTIVE

To examine the contribution of child, maternal and household factors in stunting, wasting and underweight among children under 5 years in Ethiopia.

DESIGN

Quantitative cross-sectional design based on nationally representative data.

SETTING

Urban and rural areas of Ethiopia.ParticipantsYounger (0-24 months; n 4199) and older age groups (25-59 months; n 5497), giving a total of 9696 children.

RESULTS

Among the younger age group, 29 % were stunted, 14 % were wasted and 19 % were underweight; and among the older age group, the prevalence of stunting, wasting and underweight was 47, 8 and 28 %, respectively. Being female, intake of multiple micronutrients, household having a piped source of drinking-water, high maternal BMI, higher household wealth and higher maternal education were associated with decreased odds of at least one form of undernutrition in both groups. On the other hand, children who were anaemic, had low birth weight, drank from a bottle, and children of stunted or wasted or working mothers were more likely to be stunted, wasted or underweight in both groups (P&lt;0·05). While most predictors and/or risk factors followed a similar pattern across the two age groups, child factors had higher leverage in the younger than the older group across the three forms of undernutrition.

CONCLUSIONS

Multiple set of factors predicted childhood undernutrition in Ethiopia. The study underscores the importance of intervening in the first 1000 days through promoting maternal education, maternal-child health services, mother's nutrition and improving intrahousehold food distribution.

Perspective: What Does Stunting Really Mean? A Critical Review of the Evidence

The past decade has seen an unprecedented increase in attention to undernutrition, and drastically reducing child stunting has become a global development objective. The strong focus on linear growth retardation and stunting has enabled successful advocacy for nutrition, but with this focus has come some confusion and misunderstanding about the meaning of linear growth retardation and stunting among researchers, donors, and agencies active in nutrition. Motivated by the belief that a sharp focus will further accelerate progress in reducing undernutrition, we critically reviewed the evidence. The global attention to stunting is based on the premise that any intervention aimed at improving linear growth will subsequently lead to improvements in the correlates of linear growth retardation and stunting. Current evidence and understanding of mechanisms does not support this causal thinking, with 2 exceptions: linear growth retardation is a cause of difficult births and poor birth outcomes. Linear growth retardation is associated with (but does not cause) delayed child development, reduced earnings in adulthood, and chronic diseases. We thus propose distinguishing 2 distinctly different meanings of linear growth retardation and stunting. First, the association between linear growth retardation (or stunting) and other outcomes makes it a useful marker. Second, the causal links with difficult births and poor birth outcomes make linear growth retardation and stunting outcomes of intrinsic value. In many cases a focus on linear growth retardation and stunting is not necessary to improve the well-being of children; in many other cases, it is not sufficient to reach that goal; and for some outcomes, promoting linear growth is not the most cost-efficient strategy. We appeal to donors, program planners, and researchers to be specific in selecting nutrition outcomes and to target those outcomes directly.

Associations between contraception and stunting in Guatemala: secondary analysis of the 2014-2015 Demographic and Health Survey

BACKGROUND

There has been limited research on the relationship between contraception and child growth in low-income and middle-income countries (LMICs). This study examines the association between contraception and child linear growth in Guatemala, an LMIC with a very high prevalence of child stunting. We hypothesise that contraceptive use is associated with better child linear growth and less stunting in Guatemala.

METHODS

Using representative national data on 12 440 children 0-59 months of age from the 2014-2015 Demographic and Health Survey in Guatemala, we constructed multivariable linear and Poisson regression models to assess whether child linear growth and stunting were associated with contraception variables. All models were adjusted for a comprehensive set of prespecified confounding variables.

RESULTS

Contraceptive use was generally associated with modest, statistically significant greater height-for-age z-score. Current use of a modern method for at least 15 months was associated with a prevalence ratio of stunting of 0.87 (95% CI 0.81 to 0.94; p<0.001), and prior use of a modern method was associated with a prevalence ratio of stunting of 0.93 (95% CI 0.87 to 0.98; p<0.05). The severe stunting models found generally similar associations with modern contraceptive use as the stunting models. There was no significant association between use of a modern method for less than 15 months and the prevalence ratio of stunting or severe stunting.

CONCLUSIONS

Contraceptive use was associated with better child linear growth and less child stunting in Guatemala. In addition to the human rights imperative to expand contraceptive access and choice, family planning merits further study as a strategy to improve child growth in Guatemala and other countries with high prevalence of stunting.

The influence of maternal height on offspring's birth weight in Merida, Mexico

OBJECTIVES

To analyze the influence of maternal height (MH) on offspring's birth weight (BW) in infants born from January 2016 to May 2017, in Merida, Mexico.

METHODS

A total of 3462 singletons born at term in a public hospital were analyzed. Data extracted from hospital records were MH; number of previous births; and infant's sex, BW, and gestational length. MH was divided into 4 categories at quartile points: Q1:129-147, Q2:148-151, Q3:152-155, and Q4:156-180 cm. BW data were transformed to z-score values using the WHO Child Growth Standard. The association between MH and infants' BW was analyzed through a multiple regression model in which gestational length, infant's sex, maternal age, ethnicity, and number of previous birth were included as covariates.

RESULTS

Mean values of MH and infants' BW were 151.43 cm (SD = 6.32) and 3172 g (SD = 401) (corresponding to -0.29 SD in BW z-score), respectively. The regression model showed that the shortest quartile of MH was associated with -0.43 (95% CI -0.35 -0.51) SD in infants' BW compared with the highest quartile. The second and third shortest quartiles of MH were associated with -0.24 (95% CI -0.16 -0.32) and -0.17 (95% CI -0.09 -0.25) SD of infants BW, respectively.

CONCLUSIONS

MH remains an important factor for infant BW even in the presence of other determinants. The influence of MH on infants' BW in this population is similar to that found in other populations in low-, middle-, and high-income countries.

Role of maternal preconception nutrition on offspring growth and risk of stunting across the first 1000 days in Vietnam: A prospective cohort study

Growing evidence supports the role of preconception maternal nutritional status (PMNS) on birth outcomes; however, evidence of relationships with child growth are limited. We examined associations between PMNS (height, weight and body mass index- BMI) and offspring growth during the first 1000 days. We used prospective cohort data from a randomized-controlled trial of preconception micronutrient supplementation in Vietnam, PRECONCEPT (n = 1409). Poisson regression models were used to examine associations between PMNS and risk of offspring stunting (<-2 HAZ) at 2 years. We used path analytic models to examine associations with PMNS on fetal growth (ultrasound measurements) and offspring HAZ at birth and 2 years. All models were adjusted for child age, sex, gestational weight gain, education, socioeconomic status and treatment group. A third of women had a preconception height < 150cm or weight < 43 kg. Women with preconception height < 150 cm or a weight < 43 kg were at increased risk of having a stunted child at 2 years (incident risk ratio IRR: 1.85, 95% CI 1.51–2.28; IRR 1.35, 95% CI 1.10–1.65, respectively). While the traditional low BMI cut-off (< 18.5 kg/m²) was not significant, lower BMI cut-offs (< 17.5 kg/m² or < 18.0 kg/m²) were significantly associated with 1.3 times increased risk of child stunting. In path models, PMNS were positively associated with fetal growth (ultrasound measurements) and offspring HAZ at birth and 2 years. For each 1 standard deviation (SD) increase in maternal height and weight, offspring HAZ at 2 years increased by 0.30 SD and 0.23 SD, respectively. In conclusion, PMNS influences both offspring linear growth and risk of stunting across the first 1000 days. These findings underscore the importance of expanding the scope of current policies and strategies to include the preconception period in order to reduce child stunting.

Comparative Models of Biological and Social Pathways to Predict Child Growth through Age 2 Years from Birth Cohorts in Brazil, India, the Philippines, and South Africa

Background

Early growth faltering accounts for one-third of child deaths, and adversely impacts the health and human capital of surviving children. Social as well as biological factors contribute to growth faltering, but their relative strength and interrelations in different contexts have not been fully described.

Objective

The aim of this study was to use structural equation modelling to explore social and biological multidetermination of child height at age 2 y in longitudinal data from 4 birth cohort studies in low- and middle-income countries.

Methods

We analyzed data from 13,824 participants in birth cohort studies in Brazil, India, the Philippines, and South Africa. We used exploratory structural equation models, with height-for-age at 24 mo as the outcome to derive factors, and path analysis to estimate relations among a wide set of social and biological variables common to the 4 sites.

Results

The prevalence of stunting at 24 mo ranged from 14.0% in Brazil to 67.7% in the Philippines. Maternal height and birthweight were strongly predictive of height-for-age at 24 mo in all 4 sites (all P values <0.001). Three social-environmental factors, which we characterized as "child circumstances," "family socioeconomic status," and "community facilities," were identified in all sites. Each social-environmental factor was also strongly predictive of height-for-age at 24 mo (all P values <0.001), with some relations partly mediated through birthweight. The biological pathways accounted for 59% of the total explained variance and the social-environmental pathways accounted for 41%. The resulting path coefficients were broadly similar across the 4 sites.

Conclusions

Early child growth faltering is determined by both biological and social factors. Maternal height, itself a marker of intergenerational deprivation, strongly influences child height at 2 y, including indirect effects through birthweight and social factors. However, concurrent social factors, many of which are modifiable, directly and indirectly contribute to child growth. This study highlights opportunities for interventions that address both biological and social determinants over the long and short term.

Catch-up growth in stunted children: Definitions and predictors

This paper examines the incidence and correlates of linear growth catch up in early childhood among stunted children, using a range of definitions of catch up. Catch-up growth between two and five years of age is defined in both absolute terms (i.e. the centimetre height deficit from the healthy reference population mean is reduced) and relative terms (the height-for-age z-score improved or passed the -2SD or -1SD cut-off points). Data from a cohort study from urban South Africa are used to estimate the percentage of children who caught up and the predictors of catch-up growth according to these varying definitions. The results show that our sample of stunted children exhibits catch-up growth regardless of the definition used, however prevalence of catch up is highly sensitive to the way catch up is classified, ranging from 19%-93%. Of the biological, early growth, socioeconomic status and maternal reproductive variables included in the multivariate probit regressions, only a few were found to be consistent predictors of the incidence of catch-up growth. Mother’s height was positively correlated with the incidence of catch-up growth and early stunting at one year was associated with a lower likelihood of subsequent catch up.

Adolescent mothers' anthropometrics and grandmothers' schooling predict infant anthropometrics in Ethiopia, India, Peru, and Vietnam

We investigated intergenerational associations of adolescent mothers' and grandmothers' anthropometrics and schooling with adolescent mothers' offspring's anthropometrics in Ethiopia, India, Peru, and Vietnam. We examined birthweight (n = 283), birthweight Z-score (BWZ), conditional growth in weight-for-age Z-score (cWAZ, residuals from a regression of WAZ at last survey round on BWZ, sex, and age), and height-for-age Z-score (HAZ) of children born to older cohort adolescent girls in the Young Lives study. Our key independent variables were adolescent mothers' body size: HAZ and body-mass-index-for-age Z-score (BMIZ) at age 8, conditional HAZ (cHAZ, residuals from a regression of HAZ at the end of a growth period on prior HAZ, age, and sex), conditional BMIZ growth (cBMIZ, calculated analogously), and grandmaternal BMIZ, HAZ, and schooling. We adjusted for child, maternal, and household characteristics. Adolescent mothers' cHAZ (ages 8-15) predicted birthweight (β = 130 g, 95% confidence interval (CI) 31-228), BWZ (β = 0.31, CI 0.09-0.53), and cWAZ (β = 0.28, CI 0.04-0.51). Adolescent mothers' BMIZ at age 8 predicted birthweight (β = 79 g, CI 16-43) and BWZ (β = 0.22, CI 0.08-0.36). Adolescent mothers' cBMIZ (ages 12-15) predicted child cWAZ and HAZ. Grandmothers' schooling predicted grandchild birthweight (β = 22 g, CI 1-44) and BWZ (β = 0.05, CI 0.01-0.10).

Anthropometric indices for non-pregnant women of childbearing age differ widely among four low-middle income populations

Background

Maternal stature and body mass indices (BMI) of non-pregnant women (NPW) of child bearing age are relevant to maternal and offspring health. The objective was to compare anthropometric indices of NPW in four rural communities in low- to low-middle income countries (LMIC).

Methods

Anthropometry and maternal characteristics/household wealth questionnaires were obtained for NPW enrolled in the Women First Preconception Maternal Nutrition Trial. Body mass index (BMI, kg/m²) was calculated. Z-scores were determined using WHO reference data.

Results

A total of 7268 NPW participated in Equateur, DRC (n = 1741); Chimaltenango, Guatemala (n = 1695); North Karnataka, India (n = 1823); and Thatta, Sindh, Pakistan (n = 2009). Mean age was 23 y and mean parity 1.5. Median (P25-P75) height (cm) ranged from 145.5 (142.2–148.9) in Guatemala to 156.0 (152.0–160.0) in DRC. Median weight (kg) ranged from 44.7 (39.9–50.3) in India to 52.7 (46.9–59.8) in Guatemala. Median BMI ranged from 19.4 (17.6–21.9) in India to 24.9 (22.3–28.0) in Guatemala. Percent stunted (<−2SD height for age z-score) ranged from 13.9% in DRC to 80.5% in Guatemala; % underweight (BMI <18.5) ranged from 1.2% in Guatemala to 37.1% in India; % overweight/obese (OW, BMI ≥25.0) ranged from 5.7% in DRC to 49.3% in Guatemala. For all sites, indicators for higher SES and higher age were associated with BMI. Lower SES women were underweight more frequently and higher SES women were OW more frequently at all sites. Younger women tended to be underweight, while older women tended to be OW.

Conclusions

Anthropometric data for NPW varied widely among low-income rural populations in four countries located on three different continents. Global comparisons of anthropometric measurements across sites using standard reference data serve to highlight major differences among populations of low-income rural NPW and assist in evaluating the rationale for and the design of optimal intervention trials.

Trial registration

ClinicalTrials.gov #NCT01883193 (18 June 2013, retrospectively registered)

Maternal care mediates the effects of nutrition and responsive stimulation interventions on young children's growth

BACKGROUND

Undernutrition contributes to at least half the estimated six million annual childhood deaths worldwide. Furthermore, one in three children fails to meet their developmental potential because of risks including stunting, illness, under-stimulation, poor responsive interactions and maternal depressive symptoms. Our study investigates the role of caregiving processes on children's height-for-age at 2 and 4 years.

METHODS

The Pakistan Early Child Development Scale-up study assessed the longitudinal effectiveness of early nutrition and responsive stimulation interventions on growth and development at 4 years of age. In total, 1302 children were followed up from birth to 4 years. We leveraged path analyses to explore potential mediators of early intervention effects on children's height-for-age at 4 years, including maternal depressive symptoms, mother-child interaction quality, diarrhoeal illness and height-for-age at 2 years.

RESULTS

Our final model had excellent model fit (comparative fix index = 0.999, Tucker-Lewis index = 0.998, root mean square error of approximation = 0.008) and showed that mother-child interaction quality mediated the effects of both enhanced nutrition and responsive stimulation interventions on height-for-age at 4 years via its longitudinal stability from 2 years of age (β = 0.016, p = 0.005; β = 0.048, p < 0.001, respectively). Further, diarrhoeal illness mediated the effects of maternal depressive symptoms at 1 year post partum on children's height-for-age at 4 years via the longitudinal stability of height-for-age z-score from 2 years of age onwards (β = -0.007, p = 0.019).

CONCLUSIONS

The quality of early caregiving experience mediated the association between both interventions and height-for-age. The effect of maternal depressive symptoms on growth was mediated by diarrhoeal illness. Programmatic approaches to child nutrition and growth must address all these potentially modifiable factors.

Birth Weight and Intelligence in Young Adulthood and Midlife

OBJECTIVES

We examined the associations between birth weight and intelligence at 3 different adult ages.

METHODS

The Copenhagen Perinatal Cohort is comprised of children born in Copenhagen from 1959 to 1961. Information on birth weight and ≥1 tests of intelligence was available for 4696 members of the cohort. Intelligence was assessed at a mean age of 19 years with the Børge Priens Prøve test, at age 28 years with the Wechsler Adult Intelligence Scale, and at age 50 years with the Intelligenz-Struktur-Test 2000 R.

RESULTS

Birth weight was significantly associated with intelligence at all 3 follow-up assessments, with intelligence scores increasing across 4 birth weight categories and declining for the highest birth weight category. The adjusted differences between those in the <2.5kg birth weight group and those in the 3.5 to 4.00kg group were >5 IQ points at all 3 follow-up assessments, corresponding to one-third of a SD. The association was stable from young adulthood into midlife,and not weaker at age 50 years. Adjustment for potential confounding factors, including infant socioeconomic status and gestational age, did not dilute the associations, and associations with intelligence were evident across the normal birth weight range and so were not accounted for by low birth weight only.

CONCLUSIONS

The association between birth weight and intelligence is stable from young adulthood into midlife. These long-term cognitive consequences may imply that even small shifts in the distribution of birth size, in normal-sized infants as well, may have a large impact at the population level.

Adult height, nutrition, and population health

In this review, the potential causes and consequences of adult height, a measure of cumulative net nutrition, in modern populations are summarized. The mechanisms linking adult height and health are examined, with a focus on the role of potential confounders. Evidence across studies indicates that short adult height (reflecting growth retardation) in low- and middle-income countries is driven by environmental conditions, especially net nutrition during early years. Some of the associations of height with health and social outcomes potentially reflect the association between these environmental factors and such outcomes. These conditions are manifested in the substantial differences in adult height that exist between and within countries and over time. This review suggests that adult height is a useful marker of variation in cumulative net nutrition, biological deprivation, and standard of living between and within populations and should be routinely measured. Linkages between adult height and health, within and across generations, suggest that adult height may be a potential tool for monitoring health conditions and that programs focused on offspring outcomes may consider maternal height as a potentially important influence.