National, regional, and global estimates of low birthweight in 2020, with trends from 2000: a systematic analysis.

BACKGROUND: Low birthweight (LBW; <2500 g) is an important predictor of health outcomes throughout the life course. We aimed to update country, regional, and global estimates of LBW prevalence for 2020, with trends from 2000, to assess progress towards global targets to reduce LBW by 30% by 2030. METHODS: For this systematic analysis, we searched population-based, nationally representative data on LBW from Jan 1, 2000, to Dec 31, 2020. Using 2042 administrative and survey datapoints from 158 countries and areas, we developed a Bayesian hierarchical regression model incorporating country-specific intercepts, time-varying covariates, non-linear time trends, and bias adjustments based on data quality. We also provided novel estimates by birthweight subgroups. FINDINGS: An estimated 19·8 million (95% credible interval 18·4-21·7 million) or 14·7% (13·7-16·1) of liveborn newborns were LBW worldwide in 2020, compared with 22·1 million (20·7-23·9 million) and 16·6% (15·5-17·9) in 2000-an absolute reduction of 1·9 percentage points between 2000 and 2020. Using 2012 as the baseline, as this is when the Global Nutrition Target began, the estimated average annual rate of reduction from 2012 to 2020 was 0·3% worldwide, 0·85% in southern Asia, and 0·59% in sub-Saharan Africa. Nearly three-quarters of LBW births in 2020 occurred in these two regions: of 19 833 900 estimated LBW births worldwide, 8 817 000 (44·5%) were in southern Asia and 5 381 300 (27·1%) were in sub-Saharan Africa. Of 945 300 estimated LBW births in northern America, Australia and New Zealand, central Asia, and Europe, approximately 35·0% (323 700) weighed less than 2000 g: 5·8% (95% CI 5·2-6·4; 54 800 [95% CI 49 400-60 800]) weighed less than 1000 g, 9·0% (8·7-9·4; 85 400 [82 000-88 900]) weighed between 1000 g and 1499 g, and 19·4% (19·0-19·8; 183 500 [180 000-187 000]) weighed between 1500 g and 1999 g. INTERPRETATION: Insufficient progress has occurred over the past two decades to meet the Global Nutrition Target of a 30% reduction in LBW between 2012 and 2030. Accelerating progress requires investments throughout the lifecycle focused on primary prevention, especially for adolescent girls and women living in the most affected countries. With increasing numbers of births in facilities and advancing electronic information systems, improvements in the quality and availability of administrative LBW data are also achievable. FUNDING: The Children's Investment Fund Foundation; the UNDP-UNFPA-UNICEF-WHO World Bank Special Programme of Research, Development and Research Training in Human Reproduction; and the Bill & Melinda Gates Foundation.

National, regional, and global estimates of preterm birth in 2020, with trends from 2010: a systematic analysis.

BACKGROUND: Preterm birth is the leading cause of neonatal mortality and is associated with long-term physical, neurodevelopmental, and socioeconomic effects. This study updated national preterm birth rates and trends, plus novel estimates by gestational age subgroups, to inform progress towards global health goals and targets, and aimed to update country, regional, and global estimates of preterm birth for 2020 in addition to trends between 2010 and 2020. METHODS: We systematically searched population-based, nationally representative data on preterm birth from Jan 1, 2010, to Dec 31, 2020 and study data (26 March-14 April, 2021) for countries and areas with no national-level data. The analysis included 679 data points (86% nationally representative administrative data [582 of 679 data points]) from 103 countries and areas (62% of countries and areas having nationally representative administrative data [64 of 103 data points]). A Bayesian hierarchical regression was used for estimating country-level preterm rates, which incoporated country-specific intercepts, low birthweight as a covariate, non-linear time trends, and bias adjustments based on a data quality categorisation, and other indicators such as method of gestational age estimation. FINDINGS: An estimated 13·4 million (95% credible interval [CrI] 12·3-15·2 million) newborn babies were born preterm (<37 weeks) in 2020 (9·9% of all births [95% CrI 9·1-11·2]) compared with 13·8 million (12·7-15·5 million) in 2010 (9·8% of all births [9·0-11·0]) worldwide. The global annual rate of reduction was estimated at -0·14% from 2010 to 2020. In total, 55·6% of total livebirths are in southern Asia (26·8% [36 099 000 of 134 767 000]) and sub-Saharan Africa (28·7% [38 819 300 of 134 767 000]), yet these two regions accounted for approximately 65% (8 692 000 of 13 376 200) of all preterm births globally in 2020. Of the 33 countries and areas in the highest data quality category, none were in southern Asia or sub-Saharan Africa compared with 94% (30 of 32 countries) in high-income countries and areas. Worldwide from 2010 to 2020, approximately 15% of all preterm births occurred at less than 32 weeks of gestation, requiring more neonatal care (<28 weeks: 4·2%, 95% CI 3·1-5·0, 567 800 [410 200-663 200 newborn babies]); 28-32 weeks: 10·4% [9·5-10·6], 1 392 500 [1 274 800-1 422 600 newborn babies]). INTERPRETATION: There has been no measurable change in preterm birth rates over the last decade at global level. Despite increasing facility birth rates and substantial focus on routine health data systems, there remain many missed opportunities to improve preterm birth data. Gaps in national routine data for preterm birth are most marked in regions of southern Asia and sub-Saharan Africa, which also have the highest estimated burden of preterm births. Countries need to prioritise programmatic investments to prevent preterm birth and to ensure evidence-based quality care when preterm birth occurs. Investments in improving data quality are crucial so that preterm birth data can be improved and used for action and accountability processes. FUNDING: The Children's Investment Fund Foundation and the UNDP, United Nations Population Fund-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction.

Validation of MINORMIX Approach for Estimation of Low Birthweight Prevalence Using a Rural Nepal Dataset.

BACKGROUND: The Global Nutrition Target of reducing low birthweight (LBW) by ≥30% between 2012 and 2025 has led to renewed interest in producing accurate, population-based, national LBW estimates. Low- and middle-income countries rely on household surveys for birthweight data. These data are frequently incomplete and exhibit strong "heaping." Standard survey adjustment methods produce estimates with residual bias. The global database used to report against the LBW Global Nutrition Target adjusts survey data using a new MINORMIX (multiple imputation followed by normal mixture) approach: 1) multiple imputation to address missing birthweights, followed by 2) use of a 2-component normal mixture model to account for heaping of birthweights. OBJECTIVES: To evaluate the performance of the MINORMIX birthweight adjustment approach and alternative methods against gold-standard measured birthweights in rural Nepal. METHODS: As part of a community-randomized trial in rural Nepal, we measured "gold-standard" birthweights at birth and returned 1-24 mo later to collect maternally reported birthweights using standard survey methods. We compared estimates of LBW from maternally reported data derived using: 1) the new MINORMAX approach; 2) the previously used Blanc-Wardlaw adjustment; or 3) no adjustment for missingness or heaping against our gold standard. We also assessed the independent contribution of multiple imputation and curve fitting to LBW adjustment. RESULTS: Our gold standard found 27.7% of newborns were LBW. The unadjusted LBW estimate based on maternal report with simulated missing birthweights was 14.5% (95% CI: 11.6, 18.0%). Application of the Blanc-Wardlaw adjustment increased the LBW estimate to 20.6%. The MINORMIX approach produced an estimate of 26.4% (95% CI: 23.5, 29.3%) LBW, closest to and with bounds encompassing the measured point estimate. CONCLUSIONS: In a rural Nepal validation dataset, the MINORMIX method generated a more accurate LBW estimate than the previously applied adjustment method. This supports the use of the MINORMIX method to produce estimates for tracking the LBW Global Nutrition Target.

Study protocol for UNICEF and WHO estimates of global, regional, and national low birthweight prevalence for 2000 to 2020.

Background Reducing low birthweight (LBW, weight at birth less than 2,500g) prevalence by at least 30% between 2012 and 2025 is a target endorsed by the World Health Assembly that can contribute to achieving Sustainable Development Goal 2 (Zero Hunger) by 2030. The 2019 LBW estimates indicated a global prevalence of 14.6% (20.5 million newborns) in 2015. We aim to develop updated LBW estimates at global, regional, and national levels for up to 202 countries for the period of 2000 to 2020. Methods Two types of sources for LBW data will be sought: national administrative data and population-based surveys. Administrative data will be searched for countries with a facility birth rate ≥80% and included when birthweight data account for ≥80% of UN estimated live births for that country and year. Surveys with birthweight data published since release of the 2019 edition of the LBW estimates will be adjusted using the standard methodology applied for the previous estimates. Risk of bias assessments will be undertaken. Covariates will be selected based on a conceptual framework of plausible associations with LBW, covariate time-series data quality, collinearity between covariates and correlations with LBW. National LBW prevalence will be estimated using a Bayesian multilevel-mixed regression model, then aggregated to derive regional and global estimates through population-weighted averages. Conclusion Whilst availability of LBW data has increased, especially with more facility births, gaps remain in the quantity and quality of data, particularly in low-and middle-income countries. Challenges include high percentages of missing data, lack of adherence to reporting standards, inaccurate measurement, and data heaping. Updated LBW estimates are important to highlight the global burden of LBW, track progress towards nutrition targets, and inform investments in programmes. Reliable, nationally representative data are key, alongside investments to improve the measurement and recording of an accurate birthweight for every baby.

Improving estimates of the burden of severe wasting: analysis of secondary prevalence and incidence data from 352 sites.

INTRODUCTION: Estimates of incident cases of severe wasting among young children are not available for most settings but are needed for optimal planning of treatment programmes and burden estimation. To improve programme planning, global guidance recommends a single 'incidence correction factor' of 1.6 be applied to available prevalence estimates to account for incident cases. This study aimed to update estimates of the incidence correction factor to improve programme planning and inform the approach to burden estimation for severe wasting. METHODS: A global call was issued for secondary data from severe wasting treatment programmes including prevalence, population size, programme admission and programme coverage through a UNICEF-led effort. Site-specific incidence correction factors were calculated as the number of incident cases (annual programme admissions/programme coverage) divided by the number of prevalent cases (prevalence*population size). Estimates were aggregated by country, region and overall using inverse-variance weighted random-effects meta-analysis. RESULTS: We estimated incidence correction factors from 352 sites in 20 countries. Estimates aggregated by country ranged from 1.3 (Nigeria) to 30.1 (Burundi). Excluding implausible values, the overall incidence correction factor was 3.6 (95% CI 3.4 to 3.9). CONCLUSION: Our results suggest that incidence correction factors vary between sites and that the burden of severe wasting will often be underestimated using the currently recommended incidence correction factor of 1.6. Application of updated incidence correction factors represents a simple way to improve programme planning when incidence data are not available and could inform the approach to burden estimation.

National, regional, and worldwide estimates of low birthweight in 2015, with trends from 2000: a systematic analysis.

BACKGROUND: Low birthweight (LBW) of less than 2500 g is an important marker of maternal and fetal health, predicting mortality, stunting, and adult-onset chronic conditions. Global nutrition targets set at the World Health Assembly in 2012 include an ambitious 30% reduction in LBW prevalence between 2012 and 2025. Estimates to track progress towards this target are lacking; with this analysis, we aim to assist in setting a baseline against which to assess progress towards the achievement of the World Health Assembly targets. METHODS: We sought to identify all available LBW input data for livebirths for the years 2000-16. We considered population-based national or nationally representative datasets for inclusion if they contained information on birthweight or LBW prevalence for livebirths. A new method for survey adjustment was developed and used. For 57 countries with higher quality time-series data, we smoothed country-reported trends in birthweight data by use of B-spline regression. For all other countries, we estimated LBW prevalence and trends by use of a restricted maximum likelihood approach with country-level random effects. Uncertainty ranges were obtained through bootstrapping. Results were summed at the regional and worldwide level. FINDINGS: We collated 1447 country-years of birthweight data (281 million births) for 148 countries of 195 UN member states (47 countries had no data meeting inclusion criteria). The estimated worldwide LBW prevalence in 2015 was 14·6% (uncertainty range [UR] 12·4-17·1) compared with 17·5% (14·1-21·3) in 2000 (average annual reduction rate [AARR] 1·23%). In 2015, an estimated 20·5 million (UR 17·4-24·0 million) livebirths were LBW, 91% from low-and-middle income countries, mainly southern Asia (48%) and sub-Saharan Africa (24%). INTERPRETATION: Although these estimates suggest some progress in reducing LBW between 2000 and 2015, achieving the 2·74% AARR required between 2012 and 2025 to meet the global nutrition target will require more than doubling progress, involving both improved measurement and programme investments to address the causes of LBW throughout the lifecycle. FUNDING: Bill & Melinda Gates Foundation, The Children's Investment Fund Foundation, United Nations Children's Fund (UNICEF), and WHO.

Prevalence thresholds for wasting, overweight and stunting in children under 5 years.

OBJECTIVE: Prevalence ranges to classify levels of wasting and stunting have been used since the 1990s for global monitoring of malnutrition. Recent developments prompted a re-examination of existing ranges and development of new ones for childhood overweight. The present paper reports from the WHO-UNICEF Technical Expert Advisory Group on Nutrition Monitoring. DESIGN: Thresholds were developed in relation to sd of the normative WHO Child Growth Standards. The international definition of 'normal' (2 sd below/above the WHO standards median) defines the first threshold, which includes 2·3 % of the area under the normalized distribution. Multipliers of this 'very low' level (rounded to 2·5 %) set the basis to establish subsequent thresholds. Country groupings using the thresholds were produced using the most recent set of national surveys. SETTING: One hundred and thirty-four countries. SUBJECTS: Children under 5 years. RESULTS: For wasting and overweight, thresholds are: 'very low' (≈6 times 2·5 %). For stunting, thresholds are: 'very low' (≈12 times 2·5 %). CONCLUSIONS: The proposed thresholds minimize changes and keep coherence across anthropometric indicators. They can be used for descriptive purposes to map countries according to severity levels; by donors and global actors to identify priority countries for action; and by governments to trigger action and target programmes aimed at achieving 'low' or 'very low' levels. Harmonized terminology will help avoid confusion and promote appropriate interventions.

Socioeconomic Inequalities Persist Despite Declining Stunting Prevalence in Low- and Middle-Income Countries.

Background: Global stunting prevalence has been nearly halved between 1990 and 2016, but it remains unclear whether this decline has benefited poor and rural populations within low- and middle-income countries (LMICs). Objective: We assessed time trends in stunting among children <5 y of age (under-5) according to household wealth and place of residence in 67 LMICs. Methods: Stunting prevalence was analyzed in 217 nationally representative Demographic and Health Surveys and Multiple Indicator Cluster Surveys from 67 countries with ≥2 surveys between 1993 and 2014. National estimates were stratified by wealth and area of residence, comparing the poorest 40% with the wealthiest 60%, and those residing in urban and rural areas. Time trends were calculated for LMICs by using multilevel regression models weighted by under-5 population, with stratification by wealth and by residence. Trends in absolute (slope index of inequality; SII) and relative (concentration index; CIX) inequalities were calculated. Results: Mean prevalences in 1993 were 53.7% in low-income and 48.2% in middle-income countries, with annual average linear declines of 0.76 and 0.72 percentage points (pp), respectively. Although similar slopes of declines were observed for the poorest 40% and wealthiest 60% groups in all countries (0.78 and 0.74 pp, respectively), absolute and relative inequalities increased over time in low-income countries (SII increased from -19.3% in 1993 to -23.7% in 2014 and CIX increased from -6.2% to -10.8% in the same period). In middle-income countries, socioeconomic inequalities remained stable. Overall, stunting prevalence decreased more rapidly among rural than for urban children (0.78 and 0.55 pp, respectively). Conclusions: The prevalence of stunting is decreasing. Poor-rich gaps are stable in middle-income countries and slightly increasing in low-income countries. Rural-urban inequalities are decreasing over time.

Complementary feeding practices: Current global and regional estimates.

Insufficient quantities and inadequate quality of complementary foods, together with poor feeding practices, pose a threat to children's health and nutrition. Interventions to improve complementary feeding are critical to reduce all forms of malnutrition, and access to data to ascertain the status of complementary feeding practices is essential for efforts to improve feeding behaviours. However, sufficient data to generate estimates for the core indicators covering the complementary feeding period only became available recently. The current situation of complementary feeding at the global and regional level is reported here using data contained within the UNICEF global database. Global rates of continued breastfeeding drop from 74.0% at 1 year of age to 46.3% at 2 years of age. Nearly a third of infants 4-5 months old are already fed solid foods, whereas nearly 20% of 10-11 months old had not consumed solid foods during the day prior to their survey. Of particular concern is the low rate (28.2%) of children 6-23 months receiving at least a minimally diverse diet. Although rates for all indicators vary by background characteristics, feeding behaviours are suboptimal even in richest households, suggesting that cultural factors and poor knowledge regarding an adequate diet for young children are important to address. In summary, far too few children are benefitting from minimum complementary feeding practices. Efforts are needed not only to improve children's diets for their survival, growth, and development but also for governments to report on progress against global infant and young child feeding indicators on a regular basis.

Diet quality and risk of stunting among infants and young children in low- and middle-income countries.

Age-appropriate complementary feeding practices are far from optimal among low- and middle-income countries with available data. The evidence on the association between feeding practices and linear growth is mixed. We sought to systematically examine the association between two indictors of dietary quality-dietary diversity and animal source food (ASF) consumption (WHO, 2008)-and stunting (length-for-age z-score) employing existing data from 39 Demographic and Health Surveys. Data on 74,548 children aged 6-23 months were pooled and multiple logistic regression models, adjusting for child, maternal, and household characteristics, employed to assess the association between dietary quality and stunting. Stratified models by child age and by World Bank country-income classifications (World Bank, 2015) were also applied. Children aged 6-23 months consuming zero food groups in the previous day had a 1.345 higher odds of being stunted when compared to the reference group (≥5 food groups); those who did not consume any ASF in the previous day had a 1.436 higher odds of being stunted compared to children consuming all three types of ASF (egg, meat, and dairy). We estimated that 2,629 cases of stunting would have been averted (12.6% of those stunted) among the population studied if all children had consumed five or more food groups. Outcomes by country-income groupings showed larger associations of diet diversity and ASF consumption for upper- and lower-middle income countries compared to low-income countries. In summary, dietary diversity and ASF consumption were associated with stunting, with associations varying by stratified groups.

Breastfeeding in the 21st century: epidemiology, mechanisms, and lifelong effect.

The importance of breastfeeding in low-income and middle-income countries is well recognised, but less consensus exists about its importance in high-income countries. In low-income and middle-income countries, only 37% of children younger than 6 months of age are exclusively breastfed. With few exceptions, breastfeeding duration is shorter in high-income countries than in those that are resource-poor. Our meta-analyses indicate protection against child infections and malocclusion, increases in intelligence, and probable reductions in overweight and diabetes. We did not find associations with allergic disorders such as asthma or with blood pressure or cholesterol, and we noted an increase in tooth decay with longer periods of breastfeeding. For nursing women, breastfeeding gave protection against breast cancer and it improved birth spacing, and it might also protect against ovarian cancer and type 2 diabetes. The scaling up of breastfeeding to a near universal level could prevent 823,000 annual deaths in children younger than 5 years and 20,000 annual deaths from breast cancer. Recent epidemiological and biological findings from during the past decade expand on the known benefits of breastfeeding for women and children, whether they are rich or poor.

The Global Nutrition Report 2014: actions and accountability to accelerate the world's progress on nutrition.

In 2013, the Nutrition for Growth Summit called for a Global Nutrition Report (GNR) to strengthen accountability in nutrition so that progress in reducing malnutrition could be accelerated. This article summarizes the results of the first GNR. By focusing on undernutrition and overweight, the GNR puts malnutrition in a new light. Nearly every country in the world is affected by malnutrition, and multiple malnutrition burdens are the "new normal." Unfortunately, the world is off track to meet the 2025 World Health Assembly (WHA) targets for nutrition. Many countries are, however, making good progress on WHA indicators, providing inspiration and guidance for others. Beyond the WHA goals, nutrition needs to be more strongly represented in the Sustainable Development Goal (SDG) framework. At present, it is only explicitly mentioned in 1 of 169 SDG targets despite the many contributions improved nutritional status will make to their attainment. To achieve improvements in nutrition status, it is vital to scale up nutrition programs. We identify bottlenecks in the scale-up of nutrition-specific and nutrition-sensitive approaches and highlight actions to accelerate coverage and reach. Holding stakeholders to account for delivery on nutrition actions requires a well-functioning accountability infrastructure, which is lacking in nutrition. New accountability mechanisms need piloting and evaluation, financial resource flows to nutrition need to be made explicit, nutrition spending targets should be established, and some key data gaps need to be filled. For example, many UN member states cannot report on their WHA progress and those that can often rely on data >5 y old. The world can accelerate malnutrition reduction substantially, but this will require stronger accountability mechanisms to hold all stakeholders to account.

A review of the effectiveness of agriculture interventions in improving nutrition outcomes.

OBJECTIVES: To review the impact of agriculture interventions on nutritional status in participating households, and to analyse the characteristics of interventions that improved nutrition outcomes. DESIGN: We identified and reviewed reports describing 30 agriculture interventions that measured impact on nutritional status. The interventions reviewed included home gardening, livestock, mixed garden and livestock, cash cropping, and irrigation. We examined the reports for the scientific quality of the research design and treatment of the data. We also assessed whether the projects invested in five types of 'capital' (physical, natural, financial, human and social) as defined in the Sustainable Livelihoods Framework, a conceptual map of major factors that affect people's livelihoods. RESULTS: Most agriculture interventions increased food production, but did not necessarily improve nutrition or health within participating households. Nutrition was improved in 11 of 13 home gardening interventions, and in 11 of 17 other types of intervention. Of the 19 interventions that had a positive effect on nutrition, 14 of them invested in four or five types of capital in addition to the agriculture intervention. Of the nine interventions that had a negative or no effect on nutrition, only one invested in four or five types of capital. CONCLUSIONS: Those agriculture interventions that invested broadly in different types of capital were more likely to improve nutrition outcomes. Those projects which invested in human capital (especially nutrition education and consideration of gender issues), and other types of capital, had a greater likelihood of effecting positive nutritional change, but such investment is neither sufficient nor always necessary to effect change.

Maternal and infant essential fatty acid status in Havana, Cuba.

BACKGROUND: Adequate intake of essential fatty acids (EFAs) is required for optimal development of the central nervous system and visual acuity in infants. Little information exists regarding the EFA status of vulnerable populations living in Southern regions. OBJECTIVE: We examined the adequacy of EFA status in Cuban breast-feeding mothers and their infants. DESIGN: Blood and breast-milk samples were obtained from a cross-sectional sample of mothers and term infants in Havana at 2 mo postpartum. We determined the fatty acid profiles of total lipids in breast milk, plasma, and erythrocytes and assessed infant visual acuity by using Teller acuity cards. RESULTS: Of the 56 mothers and infants examined, none showed biochemical signs of poor EFA status. Compared with values reported in the literature, mothers had an adequate EFA profile in their breast milk, plasma, and erythrocytes. The docosahexaenoic acid (DHA) concentration in breast milk was 0.43 +/- 0.26% of total fatty acids. It appeared that these breast-fed infants had an adequate dietary supply of DHA, as reflected by the mean plasma and erythrocyte DHA concentrations (2.82 +/- 0.84% and 7.41 +/- 1.16% of total fatty acids, respectively). Infant visual acuity testing showed a mean of 2.00 +/- 0.68 cycles/degree, which is within the normal range of mean binocular acuities for 2-mo-old term infants. The data did not show any relation between EFA concentrations and visual acuity. CONCLUSION: The results suggest that n-3 fatty acid deficiency and potential related deficits in early visual neural development are rare, if they exist at all, in breast-feeding women and their infants in Havana.