Maternal age

The age of mothers when they give birth can have important implications for their experience of pregnancy and birth. Whilst most mothers have normal pregnancies and healthy babies regardless of age, younger mothers (aged under 20) and older mothers aged over 40 have an increased risk of complications and adverse pregnancy outcomes (AIHW 2018; Cavazos-Rehg et al. 2015; Marozio et al. 2017).

The average age of mothers has been rising over time, from 30.0 in 2011 to 31.1 in 2021. Average maternal age has risen for both first-time mothers (from 28.4 years in 2011 to 29.7 in 2021) and those who have given birth previously (from 31.3 years in 2011 to 32.2 in 2021). The highest proportion of mothers were aged between 30 and 34 (more than one-third (38%) of all mothers).

Figure 1 presents data on the maternal age group of women who gave birth, by selected maternal characteristics, for 2021. Select the trend button to see how data has changed over an 11-year period.

Figure 1: Proportion of women who gave birth, by selected topic

Bar chart shows maternal age group by selected topics and a line graph shows topic trends between 2011 and 2021. 

The proportion of teenage mothers (aged under 20) has decreased over time (3.7% in 2011 compared with 1.5% in 2021), and the proportion of mothers aged 35 and over has increased (23% in 2011 compared with 26% in 2021).

Mothers aged 29 or under were more likely than those aged 30 and over to be public patients and to give birth in public hospitals.

Almost 3 in 5 First Nations mothers were aged between 20 and 29 (59%), with 30% aged 20–24. The proportion of First Nations teenage mothers (aged under 20) has been falling over time, from 19% in 2011 to 10% in 2021, with a corresponding increase in those aged 25–29 (from 25% to 30%) and 30–34 (from 15% to 19%).

For more information on maternal age see National Perinatal Data Collection annual update data table 2.1.


AIHW (Australian Institute of Health and Welfare) (2018) Teenage mothers in Australia 2015, AIHW, Australian Government, accessed 15 June 2022.

Cavazos-Rehg PA, Krauss MJ, Spitznagel EL, Bommarito K, Madden T, Olsen MA, Subramaniam H, Peipert JF and Bierut LJ (2015) ‘Maternal age and risk of labor and delivery complications’, Maternal and Child Health Journal, 19(6):1202–1211, doi:10.1007/s10995-014-1624-7.

Marozio L, Picardo E, Filippini C, Mainolfi E, Berchialla P, Cavallo F, Tancredi A and Benedetto C (2019) ‘Maternal age over 40 years and pregnancy outcome: a hospital-based survey’, Journal of Maternal-Fetal and Neonatal Medicine, 32(10):1602–1608, doi:10.1080/14767058.2017.1410793.