Over 40% of births in 2004 were to first-time mums, who, at an average age of 28 years were about two years older than their 1991 counterparts, according to the fourteenth annual report on pregnancy and childbirth in Australia released today by the Australian Institute of Health and Welfare (AIHW) National Perinatal Statistics Unit
The report, Australia's mothers and babies 2004, shows that of the 257,205 babies born to 252,871 mothers in 2004, 108,575 were born to first time mums.
'While first-time mothers are getting older, still more than half (57.9%) were younger than 30,' said Dr Elizabeth Sullivan of the National Perinatal Statistics Unit, located at the University of New South Wales.
Mothers aged 35 years or older made up 12.5% of new mothers in 2004 compared with 6.9% in 1995 when the average age of first-time mothers was 26.5 years.
Close to 20% (49,411) of all women who gave birth in 2004 were aged 35 years or older.
'This continues the upward trend in maternal age seen in recent years,' Dr Sullivan said.
Around 9.2% of babies born to first-time mothers were preterm (less than 37 weeks gestation), compared with 7.4% of babies born to women who had previously given birth.
Low birth weight (less than 2,500 grams) was more common in live born babies of first-time mothers.
The report also showed that, compared with women who had previously given birth, first-time mothers had higher rates of interventions, such as induced labour and caesarean section.
The overall increase in caesarean sections continued with close to 30% of all mothers having caesarean sections in 2004, compared with less than 20% in 1995.
'Caesarean sections were more common among older mothers and those who gave birth in private hospitals, and also for those who had previously had a caesarean section,' Dr Sullivan said.