A baby looks to his mother as he crawls across the finish line
A baby looks to his mother as he crawls across the finish line to win his heat on the track during the "Diaper Derby" event in New York August 1, 2014. The derby was held as a stunt ahead of the New York City Triathlon on Sunday. REUTERS/Carlo Allegri (UNITED STATES - Tags: SOCIETY SPORT TRIATHLON) Reuters

Middle-aged women in Australia are giving birth more than teenagers for the first time since 1932. According to the Australian Bureau of Statistics, women aged between 40 and 44 have a fertility rate three times higher than the last 30 years. However, the country's overall birth rate is at its lowest in 10 years.

The bureau has found that more Australian women are waiting to get pregnant until their late 20s with the average age of new mothers in 2013 at 29. Demography researchers attributed the overall decline of Australia's birth rate to low confidence in the economy. Demographer Bernard Salt said that Australian women believe in the "postponement philosophy" or decide to put off marriage and having children at a much later age. The declining birth rate may be reflecting people's "confidence in the future", Salt told The Australian.

The national fertility rate has fallen to 1.88 births for every woman in 2013 which is lower than 1.93 births in 2012. Historic data showed Australia's birth rate was its highest in 1961 when women had an average of 3.5 babies.

Graeme Hugo, director of the Australian Population and Migration Research Centre at Adelaide University, said it was clear that the country's birth rates were affected by the economic situation, The Australian reports. Hugo explained that people need to be confident in the economy before investing in a family. More women wait to have children later in life when they are more stable and financially capable of being mothers. He said the traditional ideas of family planning and retirement are no longer applicable.

The Australian Bureau of Statistics also reported a drop in infertility rates among the indigenous population at 2.34 births which is the lowest level since 2006. Majority of Aboriginal and Torres Strait Islander women had gave birth to their children when they were below 30 years old.

The median age of first-time Australian mothers in 2013 was at 29.3 years, while all mothers had an average age of 30.8. New South Wales was found to have the highest number of babies born in 2013 at over 100,000 births, while the Northern Territory had 4,053 babies in the same year.