Incidence of low birth weight among newborns

Percent of live births that weigh less than 2500 g out of the total of live births during the same period.

Number of live-born neonates with weight less than 2500 g at birth.

Number of live births.

Place of residence, preterm status, socioeconomic status.

Delivery registers (hospital management and information systems – HMIS). This method provides data on the incidence of low birth weight among newborns delivered in health institutions.

Household surveys which collect data on birth weight (recalled by mother) and relative size of the newborn at birth allow for an adjusted value even where many infants are not weighed at birth.

The relative size at birth and recalled birth-weight data are used to estimate incidence. UNICEF maintains a global database in which adjustments are made using survey data (mainly DHS and MICS) and administrative estimates are used where the percentage of weighed newborns is high.

See also: Percent of low birth-weight singleton live births, by parity

Population-based health surveys and data from administrative/information systems.

Routine facility information systems

Low birth weight is the single most important predictor of new­born well-being and survival. 

At 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, hard work and poor health care in pregnancy. Low birth weight is more common in developing than developed countries.

Low birth weight is caused by intrauterine growth restriction, prematurity or both. It contributes to a range of poor health outcomes: it is closely associated with fetal and neonatal mortality and morbidity, inhibited growth and cognitive development and chronic diseases later in life. Low-birth-weight infants are approximately 20 times more likely to die than heavier infants.

Obtaining reliable estimates of low birth weight in the general population is difficult, particularly in many developing coun­tries, where the majority of births occur at home and babies are not weighed. The women surveyed may not know or recall the birth weights of all their children, or they may report them incorrectly.  Promoting childbirth in health facilities where infants are weighed at birth is likely to improve the quality of data on birth weight. 

Many household surveys collect data on birth weight, but since the weights reported are mainly from facility births, these data are also subject to selection bias. Some household surveys (such as the DHS) ask mothers to state whether their baby was smaller than average or very small; and at an aggregate level these data may be used to estimate incidence of LBW at a na­tional level.  

Antenatal care, Neonatal care, Newborn health, Child health, Morbidity

World Health Organization (WHO). 2015 Global Reference List of 100 Core Health Indicators.; 2015.

World Health Organization. Monitoring, Evaluation, and Review of National Health Strategies: A Country-Led Platform for Information and Accountability.; 2011.

MEASURE Evaluation. FP and Reproductive Health Indicators Database — MEASURE Evaluation.

World Health Organization. Nutrition Landscape Information System (NLIS). Country Profile Indicators: Interpretation Guide. Geneva, Switzerland; 2010.

Gage AJ, Ali D, Suzuki C. A Guide for Monitoring and Evaluating Child Health Programs. MEASURE Evaluation. Carolina Population Center, University of North Carolina at Chapel Hill.; 2005.


Further information and related links

A draft framework for the global monitoring of the Comprehensive Implementation Plan on Maternal, Infant and Young Child Nutrition. Informal Consultation with Member States and UN Agencies on a Proposed Set of Indicators for the Global Monitoring Framework for Maternal, Infant and Young Child Nutrition, 30 September to 1 October 2013. Geneva: World Health Organization; 2013 (Retrieved from

Countdown to 2015 decade report (2000−2010): taking stock of maternal, newborn and child survival. Geneva and New York (NY): World Health Organization/United Nations Children’s Fund; 2010 (Retrieved from

Organisation for Economic Co-operation and Development. Health at a Glance 2013: OECD Indicators, Paris: OECD Publishing; 2013 (Retrieved from