Low birthweight newborns (percentage)
Rationale for use
At the population level, the proportion of babies with a low birth weight is an indicator of a multifaceted public-health problem that includes long-term maternal malnutrition, ill health, hard work and poor health care in pregnancy. On an individual basis, low birth weight is an important predictor of newborn health and survival.
Definition
Percentage of liveborn infants that weigh less than 2500 g, for a given time period.
Associated terms
Birth weight is the first weight of the fetus or newborn obtained after birth. For live births, birth weight should ideally be measured within the first hour of life before significant postnatal weight loss occurs.
Low birth weight is defined as a weight of less than 2500 g (up to and including 2499 g), irrespective of gestational age.
Low birth weight may be subdivided into very low birth weight (less than 1500 g) and extremely low birth weight (less than 1 000 g).
Live birth
Data sources
Health-service statistics: the proportion of live births with low birth weight, among births occurring in health institutions.
Household surveys: DHS include questions on birth weight as well as the mothers’ subjective assessment of the infant’s size at birth (i.e. very large, larger than average, average, smaller than average, very small), for births in the last 5 to 10 years.
Methods of estimation
Where reliable health-service statistics with a high level of coverage exist; ‘percentage of low birth weight’ births.
For household survey data, different adjustments are made according to the type of information available (numerical birth-weight data or the subjective assessment of the mother).
Disaggregation
By location (urban/rural, major regions/provinces), sex, and socioeconomic characteristics (e.g. mother’s level of education, wealth quintile).
References
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Monitoring low birth weight: an evaluation of international estimates and an updated estimation procedure
Blanc A, Wardlaw T. Monitoring low birth weight: an evaluation of international estimates and an updated estimation procedure. Bulletin of the World Health Organization, 2005, 83:178–185. -
Low birthweight: country, regional and global estimates
WHO/UNICEF. Low birthweight: country, regional and global estimates. New York, United Nations Children’s Fund and World Health Organization, 2004. -
International Classification of Diseases. 10th Revision
WHO.International Classification of Diseases. 10th Revision. Geneva, World Health Organization, 2004.
Database
- Demographic and Health Surveys
- European health for all (HFA) database, WHO Regional Office for Europe.
Comments
The large proportion of infants not weighed at birth, and the estimates based on mothers' subjective assessments constitute a significant impediment to the accurate monitoring of low birth weight.