What does this indicator tell us?
At a population level, the proportion of infants with a low birth weight is an indicator of a multifaceted public health problem that includes long-term maternal malnutrition, ill-health and poor health care in pregnancy.
Low birth weight is included as a primary outcome indicator in the core set of indicators for the Global Nutrition Monitoring Framework. It is also included in the WHO Global reference list of 100 core health indicators.
How is it defined?
Low birth weight has been defined by WHO as weight at birth of < 2500 grams (5.5 pounds).
What are the consequences and implications?
Low birth weight is caused by intrauterine growth restriction, prematurity or both. It contributes to a range of poor health outcomes; for example, it is closely associated with fetal and neonatal mortality and morbidity, inhibited growth and cognitive development, and NCDs later in life. Low birth weight infants are about 20 times more likely to die than heavier infants.
Low birth weight is more common in developing than developed countries. However, data on low birth weight in developing countries is often limited because a significant portion of deliveries occur in homes or small health facilities, where cases of infants with low birth weight often go unreported. These cases are not reflected in official figures and may lead to a significant underestimation of the prevalence of low birth weight.
Source of data
UNICEF-WHO Joint Database on Low birth weight. (http://data.unicef.org/nutrition/low-birthweight; https://www.who.int/nutgrowthdb/lbw-estimates).
WHO. Global Health Observatory (GHO) data repository. Low birth weight, prevalence (%) (Child malnutrition) (http://apps.who.int/gho/data/view.main.LBWCOUNTRYv).
Further reading
UNICEF-WHO Low birthweight estimates: Levels and trends 2000-2015. Geneva: World Health Organization; 2019 (https://www.who.int/publications/i/item/WHO-NMH-NHD-19.21).
WHO. Global nutrition targets 2025: low birth weight policy brief. Geneva: World Health Organization; 2014 (https://www.who.int/publications/i/item/WHO-NMH-NHD-14.5).
WHO, UNICEF. Global Nutrition Monitoring Framework: operational guidance for tracking progress in meeting targets for 2025. Geneva: World Health Organization; 2017 (https://www.who.int/publications/i/item/9789241513609).
WHO. Global reference list of 100 core health indicators (plus health-related SDGs). Geneva: World Health Organization; 2018 (https://www.who.int/publications/i/item/2018-global-reference-list-of-100-core-health-indicators-(-plus-health-related-sdgs)).
Internet resources
WHO. Feto-maternal nutrition and low birth weight. (http://www.who.int/nutrition/topics/feto_maternal/en/index.html).
WHO. Global targets 2025 to improve maternal, infant and young child nutrition (http://who.int/nutrition/global-target-2025/en/).
WHO. e-Library of Evidence for Nutrition Actions (eLENA). Interventions by global target. (http://www.who.int/elena/global-targets/en).
Target 3: 30% reduction in low birth weight (http://www.who.int/elena/global-targets/en/#lowbirthweight).
