Australian national birthweight percentiles by gestational age

Christine L Roberts and Paul A L Lancaster
Med J Aust 1999; 170 (3): 114-118.
Published online: 16 February 2009


Objective: To develop national birthweight percentiles by gestational age for male and female singleton infants born in Australia, and to compare the birthweight percentiles of Indigenous and non-Indigenous infants.

Design and setting: Cross-sectional study of singleton live births to Australian-born mothers from 1991 to 1994.

Main outcome measures: Birthweight percentiles by gestational age.

Results: During 1991–1994 Australian-born women gave birth to 769 077 live singleton infants. Of these, 28 230 (3.7%) were reported as births to Aboriginal or Torres Strait Islander women. Birthweight was missing for 581 (0.1%) births and gestational age was missing for 3014 (0.4%). An additional 3283 (0.4%) births were excluded because the recorded birthweights were extreme outliers for their recorded gestational ages. Indigenous women were more likely to be recorded as giving birth preterm (< 37 weeks’ gestation) than non-Indigenous women (11.6% v. 5.4%) and were more likely to give birth to small-for-gestational-age infants at term. After 34 weeks’ gestation, the median birthweights of Indigenous infants were consistently lower than those of non-Indigenous infants. At 40 weeks’ gestation the difference in the median birthweights between these two groups was 160 g for males and 130 g for females.

Conclusions: We present recent birthweight percentiles by gestational age based on national data in Australia. These percentiles provide current Australian norms for clinicians and researchers, and can provide a baseline for monitoring Indigenous perinatal outcomes.

NB: This archival article was made available in Feb 2009 as it was considered of importance. For the full article, please refer to the PDF version.

Received 24 June 2024, accepted 24 June 2024

  • Christine L Roberts
  • Paul A L Lancaster



remove_circle_outline Delete Author
add_circle_outline Add Author

Do you have any competing interests to declare? *

I/we agree to assign copyright to the Medical Journal of Australia and agree to the Conditions of publication *
I/we agree to the Terms of use of the Medical Journal of Australia *
Email me when people comment on this article

Online responses are no longer available. Please refer to our instructions for authors page for more information.