4102.0 - Australian Social Trends, 2005  
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Contents >> Population >> Recent fertility trends

Recent Fertility Trends


In 1993, babies born to women aged 30 years or older accounted for 41% of the total fertility rate. By 2003, this proportion had risen to 51%.

Australia's total fertility rate dropped below replacement level in 1976. It has remained below replacement level and declined further over the period since then. This means that the average number of babies born to a woman throughout her reproductive life would not be enough to replace herself and her partner under current age-specific fertility rates. A natural consequence of declining fertility is population ageing. Population ageing effectively amounts to a growing proportion of older people and a declining proportion of children in the population. Of specific concern is the rising demand for and cost of services for older people, such as income support, housing and health care, and the implications for the size and composition of the labour force that will be needed to support such expenditure.


Fertility refers to the actual number of live births in a population relative to its size (as distinct from the physical ability to reproduce), and is generally measured by the total fertility rate (TFR). Between 1993 and 1998, Australia experienced a slow decline in TFR from 1.86 to 1.76 babies per woman of reproductive age. For the 6 years from 1998 to 2003, fertility rates were relatively stable, varying between 1.73 and 1.76 babies per woman. In 2003 there were almost 5 million women of childbearing age in Australia. Of these women, about 5% gave birth in 2003. This proportion is down from 5.5% having babies in 1993.

The current low level of fertility in Australia is related to the fact that partnering is occurring at later ages than in the past, therefore reducing opportunities to have children and limiting the likelihood of larger families (see Australian Social Trends 2002, Fertility futures).

Measures of fertility

The data in this article come from the ABS Births collection (ABS cat. no. 3301.0).
Registration of births is the responsibility of state and territory Registrars of Births, Deaths and Marriages. Data are provided from information on a form completed by the parents of the child.

is defined as the number of live births in a population relative to its size.

Age-specific fertility
rates are the number of live births in a year to mothers at each age per 1,000 of the female population of the same age.

total fertility rate (TFR) for any given year is the sum of the age specific fertility rates for that year. It is a hypothetical measure which represents the number of babies one woman would give birth to during her lifetime if she experienced the current age specific fertility rates at each age of her reproductive life.

Replacement level fertility
is the value of the total fertility rate which is sufficient to replace the mother and her partner, taking into account those women who do not survive through reproductive ages. At current levels of mortality, replacement level is a total fertility rate of around 2.1.

Total fertility rate - 1973-2003
Graph: Total fertility rate - 1973-2003


The age at which women begin childbearing is a major determinant of lifetime family size. Delayed childbearing reduces overall fertility in several ways. Firstly, it reduces the period during which a woman can have children. Secondly, women who start having children later in life tend to have fewer children during their childbearing years than those women who start earlier in life. (endnote 1) Finally, women also face the increased risk of childlessness due to delaying childbirth. (endnote 2)

There has been a trend towards women delaying births in Australia, which can be seen in changes in the median age of all mothers. The median age of all mothers who gave birth in 1993 was 28.9 years, rising to 29.5 years in 1998 and 30.5 years in 2003.

Over the past ten years, falls in fertility rates for younger age groups (15-29 years) have not been fully offset by increases in fertility for older age groups (30-49 years). (endnote 3,4,5) In 2003, 51% of the TFR was contributed by mothers aged 30 years or over, an increase from 41% in 1993. This gradual shift in fertility towards older ages is a key factor contributing to the decline in Australia's TFR.

Total fertility rate

In Australia, a woman's reproductive years, or childbearing life, is generally considered to begin at age 15 and end when she turns 50. This span of 35 years is when a woman is considered most likely to have children.

TFR is an annual measure of fertility calculated from the number of births in a year and the estimated female population in their reproductive years at 30 June in that year. TFR is a synthetic measure which only applies to a hypothetical birth cohort of women. Compared with alternative measures, TFR is a timely and easy way to estimate the current fertility rate. It is useful for making assumptions about future fertility, which are used in calculating population projections. It can also be used to compare populations over time or between groups.

The TFR can be affected by distortions that arise from short-term influences, notably changes in the timing of births. (endnote 6) (endnote 7) It is argued that if successive groups of women delay childbearing until later in life then TFR is artificially lowered. Delaying childbirth creates a time lag before any intended children are actually born. The frequency of these intended births actually occurring is lower in these later age groups, as fertility generally declines with increasing age. Therefore, the increasing age of motherhood generally signifies a reduction in the total number of babies born per woman. This is what Australia has been experiencing from the mid-1970s to the present.

...25-29 year age group

Between 1993 and 1998, 25-29 year old women had the highest fertility rate of all age groups. In 2000, this age group slipped to become the second most fertile age group after 30-34 year olds and remained there in 2003.

Fertility of the 25-29 year age group has steadily decreased over the past decade, recording a 26% drop in fertility rate between 1993 and 2003. In 1993, women in this age group had 129.8 births per 1,000 women, falling to 102.9 births in 2003. In 1993, 25-29 year olds accounted for 35% of the TFR, dropping to 32% in 1998 and 29% in 2003.

Age specific fertility rates(a) - selected years

Graph: Age specific fertility rates(a) - selected years
(a) Births per 1,000 women.

Source: Births, Australia, 2003 (ABS cat. no. 3310.0).

...30-34 year age group

Fertility for the 30-34 year age group has slowly but steadily increased in the past decade. After overtaking 25-29 year olds as the peak fertility age group in 2000, women in the 30-34 age group experienced the highest fertility rate of all age groups.

In 2003, there were 112.5 births for every 1,000 women aged 30-34 years. This is an increase of 7% from 105.4 births per 1,000 women in 1993, and the highest it has been since 1964. Births to women in the 30-34 year age group contributed 28% of the TFR in 1993, 31% in 1998 and almost one-third of Australia's TFR in 2003.

...35-39 year age group

From the 1960s, fertility for the 35-39 year age group fell at a steady rate until 1980. From that year onward the fertility rate gradually increased to reach 38.9 births per 1,000 women in 1993 and recorded a high of 54.3 births per 1,000 women in 2003. This age group saw a 40% rise in fertility rate over the ten years from 1993 to 2003.

Women aged 35-39 years contributed 10% of the TFR in 1993, 13% in 1998 and 16% in 2003. In 2003, this contribution was equal to the contribution of 20-24 year olds.


An important driver of low fertility is the fall in the proportion of women having three or more children. (endnote 1) Australia's TFR in 2000 entailed one-quarter of all women having 3 or more children. (endnote 8) Research has estimated that if all the women who had three or more children in 2000 had two children instead, the TFR would have fallen to 1.3. (endnote 5) (endnote 8)

As most children are born to women under the age of 40, the number of children already born to a woman in her 40s usually indicates the total number of children she will ever have. The proportion of women aged 40-44 years with three or more children declined from over half (55%) in 1981 to about 38% in both 1996 and 2001.

The proportion of women with three or more children has also dropped across all age groups since 1981. For example in both 1986 and 1992, around 38% of women in the 35-39 year age group had three or more children. This proportion dropped to 33% in 1996 and 32% in 2001.

Fertility and Indigenous women

The current TFR for Aboriginal and Torres Strait Islander (Indigenous) women is 2.15, which is higher than the TFR for all women in Australia (1.75). Indigenous fertility rates in the past five years have remained stable, hovering just above replacement level. In 2003, the median age of Indigenous mothers was 24.6 years, which is six years younger than for all mothers. The median age of Indigenous mothers has remained at around this level for the past six years.

Indigenous women tend to have children earlier than all women. The most fertile age group for Indigenous women in both 1998 and 2003 was the 20-24 year age group. In comparison, the most fertile age groups for all women in 1998 was 25-29 years and in 2003 was 30-34 years.

The tendency of Indigenous women to have children at younger ages than all women contributes to the relatively high fertility of Indigenous women. In 2003, almost three-quarters of the TFR for Indigenous women was accounted for by women under 30 years of age, compared to half of the TFR for all women.

Indigenous women tend to have a lower rate of childlessness than all women and also tend to have more children than all women. ABS 1996 Census of Population and Housing data show that 8% of Indigenous women aged 45 years were childless, compared to 11% of all women. The data also show 60% of Indigenous women aged 30 years or over had had three or more children, compared to 41% of all women. In fact, four out of every ten Indigenous women aged 30 years or over had had four or more children in 1996.

In addition to births to Indigenous mothers, births to non-Indigenous mothers where the father is Indigenous contributes to Indigenous population growth. These births accounted for 27% of all Indigenous births in 2003.

Grouped age specific fertility rates(a) - selected years
Graph: Grouped age specific fertility rates(a) - selected years
(a) Births per 1,000 women.
(b) Includes births to mothers aged less than 15 years.

Source: Births, Australia, 2003 (ABS cat. no. 3301.0).


Another driver of low fertility is the number of women having no children. A recent Australian survey on fertility decisions found that 8% of surveyed women without children definitely did not want children. Reasons given for preferring not to have children included lifestyle choices, financial reasons, career and employment, health, lack of partners, fragility of relationships and dislike of children. (endnote 9)

The proportion of women aged under 30 years that do not have children has increased over the past ten years as women delay childbearing. For instance, of women aged 25-29 years in 1992, 49% did not have a child compared with 59% of women of the same age in 2001. (endnote 10) Most births now occur to mothers aged 30 years and over. In 2003, over half (51%) of the TFR was attributed to mothers aged 30 years and over. (endnote 11) For women aged 40-44 years who are nearing the end of their fertility, a greater proportion had not had children in 2001 (13%) compared with women of the same age in 1992 (10%).

...lifetime childlessness

The continued delaying of births may result in lifetime childlessness for some women (see Australian Social Trends 2002, Trends in childlessness). Lifetime childlessness is the proportion of women who have reached the end of their childbearing years and have not had any children. Of all women aged 45-49 years at the time of the ABS 1996 census of population and housing, 11% had never had a child.

Lifetime childlessness among women younger than 45-49 years (i.e. those who had not yet reached the end of their reproductive years) can only be estimated. In 2000, it was estimated that 24% of women who had not yet completed their fertility would remain childless for life if fertility rates for 2000 remained constant into the future. (endnote 8)

Proportion of women without children - selected years

Graph: Proportion of women without children - selected years
(a) ABS 1992 Survey of Families in Australia.
(b) ABS 1996 Census of Population and Housing.
(c) ABS 2001 National Health Survey.

Source: Births, Australia, 2001 (ABS cat. no. 3310.0).

International comparison of fertility

Fertility levels vary considerably between countries. In general, developed countries have lower TFRs than developing countries. Below replacement level fertility is common in most developed nations.

While Australia's TFR for 2003 of 1.75 is well below the world's average, it is mid-ranked compared with other nations in the more-developed category.


Total fertility rate
Selected countries
1990- 1995
2000- 2005

Hong Kong (SAR of China)
United Kingdom
New Zealand
United States of America
Viet Nam
Papua New Guinea

More-developed regions
Less-developed regions
Least-developed regions

Source: Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, World Population Prospects: the 2004 Revisions,


One of the most dramatic consequences of fertility decline is population ageing, which is already occurring in Australia. This is the inevitable result of sustained low fertility accompanied by increasing life expectancy.

Population projections show that the difference between a middle level fertility scenario in the future (TFR=1.6) and a low level scenario (TFR=1.3) (endnote 5) (endnote 8) equates to about one-third of Australian women having one child less. (endnote 7)

Small differences in fertility levels over the next 50 years could produce very different population outcomes. A change of 0.1 either way in the total fertility rate would result in Australia's population being almost 1.0 million larger or smaller in 2051 (see Australian Social Trends 2002, Fertility futures).


1 Barnes, A 2001, Low fertility: a discussion paper, FaCS occasional paper no. 2, Department of Family and Community Services, Canberra.

Weston, R 2004, 'Having children or not', Family Matters, no. 69, pp. 4-9.

DeVaus, D 2002, 'Fertility decline in Australia: a demographic context', Family Matters, no. 63, pp. 14-21.

Kippen, R 2003, Trends in age- and parity-specific fertility in Australia, Working paper in Demography no. 91, Australian National University, Canberra.

5 McDonald, P 2000, 'Low fertility in Australia: evidence, causes and policy responses', People and Place, vol.8, no.2, pp. 6-21.

McNicoll, G 2003, 'Introduction: Australia's population history and prospect', in The transformation of Australia's population: 1970-2030, eds Khoo, S. and McDonald, P., UNSW Press, Sydney.

McDonald, P 1998, 'Contemporary fertility patterns in Australia: first data from the 1996 Census', People and Place, Vol. 6 no. 1, pp. 1-12.

Australian Bureau of Statistics 2000, Births, Australia, 2000, cat. no. 3301.0, ABS, Canberra.

Weston, R, Qu L, Parker, R, Alexander, M 2004, "Its not for lack of wanting kids ...": A report on the Fertility Decision Making Project,, Report no. 11, Australian Institute of Family Studies, Melbourne.

10 Australian Bureau of Statistics 2001, Births, Australia, 2001, cat. no. 3301.0, ABS, Canberra.

Australian Bureau of Statistics 2004, Births, Australia, 2003, cat. no. 3301.0, ABS, Canberra.

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