Australia's mothers and babies

This section focuses on mothers who gave birth when they were aged 35 and over and their babies. With appropriate medical care, most mothers aged 35 and over have healthy pregnancies and babies, however, they remain at higher risk of developing some conditions such as gestational diabetes mellitus or pre-eclampsia (Glick et al. 2021; Li et al. 2020; Marozio et al. 2017). Babies born to mothers aged 35 and over can have a higher risk of preterm birth, fetal distress or poor fetal growth (Glick et al. 2021). In many cases, medical supervision and regular antenatal visits can safely manage or prevent these conditions (Dillon et al. 2019).

Mothers who gave birth aged 35 and over

In 2023, women who gave birth aged 35 and over accounted for 28% (77,819) of all mothers. This proportion has increased since 2010 (23%, 67,989).

Figure 1 presents trend data for women who gave birth aged 35 and over, by selected maternal characteristics, between 2010 (or earliest available year of data) and 2023.

In 2023, most mothers aged 35 and over accessed antenatal care in the first trimester (80%) and this has been generally increasing since 2013 (66%). The majority of mothers aged 35 and over had 5 or more antenatal visits (95%) in 2023, which has been relatively stable since 2018 (94%).

Since 2010, the most common onset of labour type for mothers aged 35 and over has changed from spontaneous (47% in 2010, 33% in 2023) to no labour (29% in 2010, 38% in 2023). Over the same period, the most common method of birth has changed from non-instrumental vaginal birth (48% in 2010, 41% in 2023) to caesarean section (42% in 2010, 50% in 2023), such that half of all mothers in this age group had a caesarean section in 2023.

Mothers aged 35 and over are unlikely to smoke during pregnancy, with 4.9% reporting that they smoked at any time during pregnancy in 2023. This rate has fallen over time (8.4% in 2011).

Mothers aged 35 and over experience differences in relation to maternal characteristics, health behaviours and outcomes, and perinatal outcomes, when compared to the overall population of Australian mothers and babies. These differences can be explored when viewing Maternal age at the chapter or topic level throughout this report.

Babies born to mothers aged 35 and over

In 2023, babies born to mothers aged 35 and over accounted for 28% (79,207) of all births. This proportion has increased since 2010 (23%, 69,464). 

Figure 2 presents trend data for babies born to women who gave birth aged 35 and over, by selected baby characteristics, between 2010 (or earliest available year of data) and 2023.

In 2023, most (90%) babies born to mothers aged 35 and over were born at term (born from 37 to 41 weeks) and had a normal birthweight (92%) (birthweight between 2,500 and 4,499 grams; also referred to as 'healthy birthweight'). These proportions have remained stable since 2010 (90% and 91%, respectively)

Around one in 5 babies born to mothers aged 35 and over required active resuscitation (22%) which has increased slightly since 2019 (20%). Almost 1 in 5 babies required admission to SCN/NICU (18%) which has fluctuated since 2010 (17%) with a peak of 19% in 2017.

The most common length of stay in hospital has changed over time. In 2010, 4 to 5 days was the leading length of stay (44%), which has decreased to 31% in 2023. There has been a corresponding increase of a hospital stay of less than 1 day (from 1.8% in 2010 to 3.8% in 2023), 1 day (from 8.5% in 2010 to 17% in 2023) and 2 to 3 days (from 34% in 2010 to 41% in 2023).