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 and very low birth weight is defined as <1,500 grams.

For all indicator displays, where all years of data are comparable over time an ‘All’ category will be provided as an option in the ‘Year’ drop down display. If only a selection of specific years are comparable, these years (e.g. 2017 to 2019) will be provided as an option under ‘Year’ and ‘All’ will not be an option. See the footnotes for this indicator in the supplementary tables hyperlink below for further information.

See the XLS Downloadsupplementary table for this indicator for further information and footnotes about these data.

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.

See the XLS Downloadsupplementary table for this indicator for further information and footnotes about these data.