Australian Institute of Health and Welfare data show rise in South Australian births, fall in teen mums KEEPING UP: Hannah Hull, 20, of Salisbury with Jaxon and Kobe. Noelle Bobrige Source: News Limited BIRTHS are up and so is the age of mothers, while teen mums are on the decline. Latest data shows the average age of women having their first baby has increased steadily from 27.6 years in 2002 to 28.3 years in 2011. The number of teen mums fell from 4.9 per cent to 3.7 per cent of all mothers in the same period, according to the Australian Institute of Health and Welfare (AIHW). Of all first-time mothers in 2011, 14.2 per cent were aged 35 or older, compared with 11.2 per cent in 2002. There were 630 women aged 45 and over who gave birth in 2011, with ages ranging up tothe oldest 55. The average age of mothers is now 30. Overall, in 2011, a total of 297,126 women gave birth to 301,810 babies. This was about a 1 per cent rise in the total number of births compared with 2010 and a rise of more than 18 per cent since 2002 when just 255,095 births were recorded. In SA in 2011 817 women aged over 40 gave birth, as did 809 women aged under 20. Hannah Hull, 20, of Salisbury, is one mum, defying the trend - she gave birth to her first son, Jaxson, when aged 19 and on Friday gave birth to her second boy, Kobe. "I am very happy to have my babies while I am young, fit and active, and look forward to having the energy to keep up with them as they grow," she said. I can't imagine having a baby at 40 or so, it would be very tiring, but everyone's circumstances are different. AIHW spokeswomanperson Professor Elizabeth Sullivan said the rise in birth age was matched by a rise in caesarean section births, going from 27 per cent to 32 per cent.