0.4 Low birthweight

Babies who are born with low birth weight are at greater risk of poor health and disability than other babies.

A baby may be small through being born early (pre-term) or may be small for their gestational age. Factors that may contribute to low birth weight include:

  • maternal experiences of illness, trauma or injury during pregnancy
  • inadequate prenatal care
  • alcohol and drug use (including tobacco)
  • poor maternal nutrition, physical and mental health

Low birth weight is defined as <2,500 grams.

Trend data: For all indicator displays, the yearly trend is limited to indicators with 3 or more years (including the current year) of comparable time series data. To see the trend click on “Yearly Trend” button on the display. Where 3 or more years of comparable data including the most recent year is not available, a “No time series data” message is shown on the display.

The figure shows the proportion of live born singleton infants of low birthweight, 2010 to 2018. The proportion was 6.7% for 2018

Source: AIHW National Perinatal Data Collection

See the supplementary data tables for further information and footnotes about these data.

For further information on teenage births see Australia’s mothers and babies data visualisations.

Indicator technical specifications

The information below provides technical specifications for the summary indicator data presented in the quick reference guide.

National Framework Indicator 0.4 Low birthweight: Proportion of live born infants of low birthweight
  Definition Data source
Numerator Number of low birthweight (<2,500g) live born infants in the reference period AIHW National Perinatal Data Collection
Denominator Number of births (live born) registered in the reference period AIHW National Perinatal Data Collection

Explanatory notes

The definition of low birthweight as weighing less than 2,500 grams at birth is the Australian standard and the World Health Organization standard.

Babies with low birthweight may be small due to being born early (pre-term), or may be small for their gestational age (including intrauterine growth restriction).

Only live births are included. As such, the indicator excludes stillbirths, miscarriages and terminations.