Births, Australia methodology

The scope of the statistics includes:

• all births that were live born and were not previously registered
• births that occurred within Australian Territorial waters
• births to temporary visitors to Australia
• births that occurred in Australian Antarctic Territories and other external territories
• births that occurred on Norfolk Island from 1 July 2016 are included. This is due to the introduction of the Norfolk Island Legislation Amendment Act 2015. Norfolk Island births are included in statistics for 'Other Territories' as well as totals for all of Australia. Births occurring on Norfolk Island prior to 1 July 2016 were not in scope for birth statistics
• births that occurred in transit (i.e. on ships or planes) if registered in the Australian state or territory of 'next port of call'
• births to Australian nationals employed overseas at Australian legations and consular offices (i.e. children born overseas to Australian diplomats or their families)
• births that occurred in earlier years that have not been previously registered (late registrations).

The scope of the statistics excludes:

• still births/fetal deaths (these are accounted for in perinatal death statistics published in Causes of Death, Australia (cat. no. 3303.0), and previously, Perinatal Deaths, Australia (cat. no. 3304.0))
• adoptions, sex changes, legitimations and corrections
• births to foreign diplomatic staff in Australia.

The scope for each reference year of the Birth Registrations collection includes:

• births registered in the reference year and received by the ABS in the reference year
• births registered in the reference year and received by the ABS in the first quarter of the subsequent year
• births registered in the years prior to the reference year but not received by the ABS until the reference year or the first quarter of the subsequent year, provided that these records have not been included in any statistics from earlier periods.

Birth records received by the ABS during the March quarter of 2020, which were registered in 2019, were assigned to the 2019 reference year. Any registrations relating to 2019 which were received by the ABS from April 2020 were assigned to the 2020 reference year and will be reported in the next iteration of this publication.

Prior to 2007, the scope for the reference year of the Birth Registrations collection included:

• births registered in the reference year and received by the ABS in the reference year
• births registered in the reference year and received by the ABS in the first quarter of the subsequent year
• births registered during the two years prior to the reference year but not received by the ABS until the reference year.

Ideally, for compiling annual time series, the number of births should be recorded as all those occurring within a given reference period such as a calendar year. Due to lags in registration of births and the provision of that information to the ABS from state and territory Registries of Births, Deaths and Marriages, data in this release are presented on a year of registration basis, unless otherwise stated.

There are three dates attributable to each birth registration:

• the date of occurrence (of the birth)
• the date of registration or inclusion on the state/territory register
• the month and year in which the registered birth is provided to the ABS.

Data in this release are presented according to date of registration, unless otherwise stated. The registration date differs between states and territories, and should be taken into account when analysing birth statistics:

• For births registered in New South Wales, Western Australia and the Australian Capital Territory, the birth registration date is the date at which the record is entered into the registration processing system.
• For births registered in Victoria, the birth registration date is the date at which the record is completed in system.
• For births registered in Queensland, the registration date is the date at which all mandatory data items required for a registration to be considered complete have been entered into the system at which point the registration number and registration date are automatically assigned.
• For births registered in South Australia, preliminary and final registration dates are allocated. Where a record requires further information a preliminary date is assigned. Once all data are finalised, a final registration date is assigned to the birth record which is provided to the ABS as the registration date.
• For births registered in Tasmania, an 'insertion date' is allocated when any information relating to the birth is first entered into the registration system. This is the date that is provided to the ABS.
• For births registered in the Northern Territory, the registration date is the date at which the record is entered into the registration system. For birth records not received by the Registry within 60 days of the birth, the Registry will register the child as 'not stated'.

Registration of births is the responsibility of state and territory Registries of Births, Deaths and Marriages and is based on data provided on an information form completed by the parent(s) of the child. This form is the basis of data provided to the ABS by the Registries for compilation into aggregate statistics in this release. Core data items are collected in all states and territories and therefore statistics at the national level are available for key characteristics. Some states collect additional information.

Hospitals and birth clinics notify state and territory registries of recent births on a regular basis. For births where a notification has been received by a registry, but has not been registered within the prescribed time period, parents are contacted by reminder letters and/or phone calls.

Nuptiality relates to the registered marital status of the parent(s) of the child at the time of birth. Confinements and births are classified as:

• Nuptial where the father registered was married to the mother at the time of the child's birth, or where the husband died during the mother's pregnancy (confinements and births to Aboriginal and Torres Strait Islander mothers considered to be tribally married to the father of the child are classified as nuptial).
• Ex-nuptial where the parents were not in a registered marriage at the time of the child's birth, irrespective of whether the parents were living together at the time of the birth.
• Ex-nuptial births and confinements are further classified as paternity acknowledged (where the father signed the birth registration form) or paternity not acknowledged (where the father did not sign the birth registration form).

This issue of Births, Australia includes data cubes containing birth and fertility statistics on the Australian Statistical Geography Standard (ASGS) and the Standard Australian Classification of Countries (SACC). For further information refer to:

• Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas, July 2016 (cat. no. 1270.0.55.001)
• Australian Statistical Geography Standard (ASGS): Volume 3 - Non ABS Structures, July 2019 (cat. no. 1270.0.55.003)
• Australian Statistical Geography Standard (ASGS): Volume 5 - Remoteness Structure, July 2016 (cat. no. 1270.0.55.005)
• Standard Australian Classification of Countries (SACC), 2016 (cat. no. 1269.0)

As a result of an amendment made in 1992 to section 17(a) of the Acts Interpretation Act 1901-1973 (Commonwealth), the Indian Ocean territories of Christmas Island and Cocos (Keeling) Islands have been included as part of geographic Australia since 1993, hence another category of the state and territory classification has been created. This category is known as 'Other Territories' and includes Christmas Island, the Cocos (Keeling) Islands, and Jervis Bay Territory. From 1 July 2016, Other Territories also include Norfolk Island following the introduction of the Norfolk Island Legislation Amendment Act 2015.

Prior to 1993, births to mothers usually resident in Christmas Island or Cocos (Keeling) Islands were included with Offshore areas and Migratory in Western Australia, while births to mothers usually resident in Jervis Bay Territory were included with the Australian Capital Territory. In 2019, there were 23 births to mothers usually resident in Christmas Island, the Cocos (Keeling) Islands, Jervis Bay Territory and Norfolk Island.

Birth statistics for states and territories have been compiled and presented according to the state or territory of usual residence of the mother regardless of where in Australia the birth occurred and was registered, except where otherwise stated. In the following table, data are presented on both a state or territory of registration basis and usual residence basis. Births which took place outside Australia are excluded from the statistics. Births to mothers who were usual residents of Australia's Other Territories (Christmas Island, Cocos (Keeling) Islands, Jervis Bay Territory and Norfolk Island) cannot be registered in Other Territories but are registered in other Australian states and territories.

In 2019, there were 398 births registered in Australia to women who usually lived overseas. These have been coded to 'Special purpose codes' and appear in outputs as usual residents of the state/territory total in which the birth was registered.

Age-specific and total fertility rates for sub-state/territory regions (for example, Statistical Areas Level 2) and the states and territories presented in this release are average rates for three years ending in the reference year. Rates for Australia in all other tables are based on birth registration data for the reference year only.

Parity refers to the number of (live) births that a woman has had previous to the most recent birth. Birth order refers to whether a birth is the first (i.e. no previous children), second, third or higher-order birth of the mother. When registering births, information is collected on the number of previous children born to a mother, in all states and territories.

Upon review, Australian parity figures from 2014 to 2018 were of poor quality and have not been published.

In 2019, parity data includes registration information from all states and territories with the exception of Queensland. Queensland is the only state that collects parity data where the father recorded on the birth certificate, is the same father of previous children of the mother. All other states and territories collect information on previous children of the mother regardless of paternity. 

These data are collected as a result of the demand for parity data for analysis and dissemination. For more information on the use of parity data and collection methods associated with these statistics, see Corr, P. and Kippen, R. 2006, The Case for Parity and Birth-Order Statistics, Australia and New Zealand Journal of Statistics, vol. 48, no. 2, pp. 171-200.

In recent years there have been small number of twin and higher order births from the same confinement that are registered in different reference years. Due to this reason, the number of twin and higher order births registered in a reference year may not match the number of such confinements registered in that year. For more information on the coverage of a reference year, see Scope and coverage.

During editing processes for the births collection, some items are set to unknown where information is missing. In 2019, there were 1,044 birth registrations for which the Statistical Area of usual residence could not be determined. These have been coded to 'Special purpose codes'. These registrations are included as usual residents in the state/territory in which the birth was registered.

Each year, a small number of birth registrations record the mother or father's age (as at the birth of the child) as different to that which is derived using their date of birth and the date of birth of the child. In 2019, there were 519 records for which the derived age of the mother was found to be inconsistent with the reported age. For these records, the derived age of the mother was used. The same process was applied to information on the father's age, for which 480 records were affected.

To protect confidentiality, the Australian Bureau of Statistics (ABS) has adopted a technique to randomly adjust cells with small values. Cells with a value of zero have not been affected by this randomisation. As a result, sums of components may not add exactly to totals. The technique has been applied to all data issued in this release with the exception of median age calculations and any sub-state data. These very minor adjustments allow for a greater amount of data to be released, and as they are small, do not affect the utility of the data.

The Census and Statistics Act 1905 provides the authority for the ABS to collect statistical information, and requires that statistical output shall not be published or disseminated in a manner that is likely to enable the identification of a particular person or organisation. This requirement means that the ABS must take care and make assurances that any statistical information about individual respondents cannot be derived from published data.

Where necessary, tables in this release have had small values suppressed or randomised to protect confidentiality. As a result, sums of components may not add exactly to totals. These adjustments allow for a greater amount of detailed data to be released, and, as they are small, do not affect the utility of the data.

Calculations as shown in the commentary sections of this release are based on unrounded figures. Calculations undertaken by data users using rounded figures may differ from those released. Where figures have been rounded in tables, discrepancies may occur between sums of component items and totals.

In June 2014, the New South Wales Registry of Births, Deaths and Marriages (NSW Registry) transitioned to a new data processing system which resulted in temporary processing delays. These delays caused a number of birth records received by the NSW Registry in 2014 to be processed in 2015. As a result, the total number of births registered in New South Wales in 2014 (91,074) was 9,388 (9.3%) less than the number registered in 2013 (100,462). For births data occurring in New South Wales for 2014, versus registrations, view dataset Births, by year and month of occurrence, by state (in this publication).

Analysis by the ABS showed that the distribution of important characteristics such as sex of child, age of mother, usual residence of mother and Indigenous status in 2014 data is similar to that in 2011-2013 data. The delayed birth registrations contributed to the increase of 9,005 registrations between 2014 and 2015. There was a greater registration lag, indicated by the high proportion of births registered in New South Wales in 2015 that occurred in 2014. After taking account of the extra lag, a decline in registrations after 2013 is still apparent.

In 2016 and 2017, there were lower than expected registration counts for New South Wales. The ABS worked with the NSW Registry to investigate these counts, noting that changes to identity requirements in 2016 had prevented some registrations from being finalised. The NSW Registry worked with parents to finalise these registrations, enabling many to be included in 2018 counts. Other initiatives also contributed to the higher count of births in New South Wales in 2018, including the implementation of an online birth registration system and a campaign aimed at increasing registrations among Aboriginal and Torres Strait Islander parents. For more information, see New South Wales Aboriginal and Torres Strait Islander birth registrations. As a result, registrations for 2018 increased by 11,043 births (11.7%). Registrations for 2019 decreased by 8,554 births (-8.1%) and thus returned to be more in line with recent levels. Care should be taken when interpreting changes in birth counts and fertility rates for New South Wales and Australia in recent years.

In 2009, the Queensland Registry of Births, Deaths and Marriages devoted significant time and resources to follow-up and finalise birth registrations where there was previously incomplete information. As part of the 'Retrospective Births Project', 1,780 births were registered, with approximately 40% registered as Aboriginal and Torres Strait Islander births. This project is now complete.

In 2017, 2018 and 2019 there has been a substantial increase in Queensland Indigenous births. Investigations into this increase highlighted that the Queensland Registry had undertaken intensive community engagement work aimed at registering and providing birth certificates to Aboriginal and Torres Strait Islander people in communities across the state. For more information see 'Queensland Aboriginal and Torres Strait Islander birth registrations under Aboriginal and Torres Strait Islander Peoples.

The Tasmanian Births, Deaths and Marriages Registration Act 1999 requires hospitals, doctors, midwives or other responsible persons to provide the Tasmanian Registry with a list of babies born containing basic information such as date of birth and sex of the baby. In the case of a live birth, the birth notification must be provided within 21 days of the birth. These notifications have been provided to the ABS since 2002 and are also used in producing quarterly population estimates.

Under the Act, the birth of a child must also be registered by lodging a birth registration statement with the Registry within 60 days after the date of birth of the child. Once the parent(s) submits the birth registration statement, the record is updated and the Registry provides the ABS with a complete registration record. Where a match between a birth notification and birth registration statement is identified, the record is quality assured to ensure completeness of the record.

Prior to 2007, records for which a birth registration form was not received were coded as 'ex-nuptial, paternity not acknowledged'. As a result, the number of ex-nuptial births in Tasmania may be overstated for 2002 to 2006. Since 2007 these records have been excluded from all nuptiality statistics. Since 2013 the ABS no longer received birth notifications, and therefore there are no more unmatched birth registration forms.

In 2018, the Northern Territory Registry of Births, Deaths and Marriages identified a processing issue that led to delays in some registrations for births that occurred in previous years being sent to the ABS. These registrations have since been received by the ABS, resulting in 355 additional births being included in 2018 data, the majority of which (339) were of Aboriginal and Torres Strait Islander children. Following this increase, registrations for 2019 decreased by 438 births (-10.8%). Care should be taken when interpreting changes in birth counts and fertility rates for the Northern Territory in recent years.

An increase in the processing of late registrations in 2018, compared to earlier years, contributed to a higher than expected fertility rate for the territory in that year. Care should be taken when interpreting changes in the Australian Capital Territory births when comparing 2018 to earlier years.

From 2006 to 2013, the Indigenous status of the mother and father for births registered in New South Wales was inconsistent with other jurisdictions. Specifically, where one parent was an Aboriginal and/or Torres Strait Islander Australian, the other parent was processed as either 'Aboriginal and Torres Strait Islander' or 'Not stated'. Furthermore, where one parent was 'Non-Indigenous', the other parent was processed as 'Non-Indigenous' or 'Not stated'. The Indigenous status of the child, where the birth was registered in New South Wales, was derived from the Indigenous status of either of the parents. The Indigenous status of births registered in New South Wales from 2006 to 2013 should therefore be interpreted with caution. The NSW Registry has since changed their processing rules and registration data since 2014 is consistent with the rest of Australia.

Recently, several initiatives by the NSW Registry, including the implementation of an online birth registration system and a campaign aimed at increasing registrations among Aboriginal and Torres Strait Islander parents, have contributed to a higher count of Aboriginal and/or Torres Strait Islander Australian births in 2018 and 2019. Aboriginal and Torres Strait Islander fertility rate for New South Wales, should be used with caution.

In 2017, Indigenous births in Australia increased by 9.9% to 20,400 births (compared to 2016). This was largely driven by a substantial increase in Queensland Indigenous births. Investigations into this increase highlighted that the Queensland Registry had undertaken intensive community engagement work aimed at registering and providing birth certificates to Aboriginal and Torres Strait Islander people in communities across the state. This work included a partnership with Pathfinders, a federally funded (by Prime Minister and Cabinet) organisation which ran a National Aboriginal Birth Certificate Program. Approximately two-thirds of the increase in registrations could be accounted for by registrations of births that occurred in previous years. Aboriginal and Torres Strait Islander fertility rate for 2017, particularly for Queensland, should be used with caution.

The number of Indigenous births with a usual residence of Queensland increased by 7.7% (490 births) in 2019, in contrast to the overall number of births in that state which decreased by 196 (0.3%).

The Queensland Registry reported they had a dedicated engagement officer and, up until Covid19, there had been a higher level of engagement activities over the previous 18 months to improve rates of under registration. This, together with the registry's expansion of their Deadly Choices program in late 2018, are possible contributing factors for the increase in registrations.

This release reports on the number and characteristics of Aboriginal and Torres Strait Islander births and fertility rates in each state and territory, excluding the Australian Capital Territory and Other Territories. Aboriginal and Torres Strait Islander data for the Australian Capital Territory and Other Territories are not analysed separately due to small numbers, but are included in totals for Australia.

The Aboriginal and Torres Strait Islander fertility rates included in this release were calculated using:

• Estimates and projections of the Aboriginal and Torres Strait Islander population, based on results of the 2016 Census of Population and Housing. For more information see Estimates and Projections, Aboriginal and Torres Strait Islander Australians.

It is also possible to derive indirect estimates and projections of numbers of Aboriginal and Torres Strait Islander births, based on 2011 Census-based Aboriginal and Torres Strait Islander population estimates:

• For 30 June 2006 to 30 June 2015, estimates of the Aboriginal and Torres Strait Islander population were derived from the Aboriginal and Torres Strait Islander resident population as at 30 June 2016 using a reverse survival technique based on Aboriginal and Torres Strait Islander life tables (see Estimates and Projections, Aboriginal and Torres Strait Islander Australians). Indirect estimates of Aboriginal and Torres Strait Islander births can then be derived using the number of Aboriginal and Torres Strait Islander children aged 0 at 30 June of each year.
• For 30 June 2017 to 30 June 2031, projections of the Aboriginal and Torres Strait Islander population were derived from the Aboriginal and Torres Strait Islander resident population as at 30 June 2016 using assumptions on future levels of Aboriginal and Torres Strait Islander fertility, mortality and migration. Numbers of projected Aboriginal and Torres Strait Islander births were derived by applying assumed fertility rates to the Aboriginal and Torres Strait Islander female population aged 15-49 years at 30 June of each year (see Estimates and Projections, Aboriginal and Torres Strait Islander Australians).

The ABS has investigated recent annual variability in the number of births of Aboriginal and Torres Strait Islander peoples. In 2019, 165 births were to mothers who reported themselves as being an Aboriginal and/or Torres Strait Islander Australian (1.1% of children to Aboriginal and/or Torres Strait Islander mothers), and who were born overseas.

Since 2011, these instances have accounted for less than 1.1% of annual births to Aboriginal and/or Torres Strait Islander mothers. Of these births in 2019, 59% were to mothers born in neighbouring countries in the Pacific, such as New Zealand, Samoa and Papua New Guinea, and of these the majority (72 births) were to mothers who reported themselves as being Torres Strait Islander, or both Aboriginal and Torres Strait Islander on the birth registration form. This may indicate that these mothers are seeking to report their Pacific Islander ancestry (for which provision is not made in the Birth Registration Statement forms in Australia) rather than reporting to be Torres Strait Islanders. However, the 12 births to mothers born in Papua New Guinea in 2019 who reported being Torres Strait Islanders may be correctly recorded.

The ABS continues to monitor this and work with Registries to improve quality assurance around these data. However, caution should be exercised when interpreting Aboriginal and Torres Strait Islander data presented in this release.

For information on the institutional environment of the Australian Bureau of Statistics (ABS), including the legislative obligations of the ABS, financing and governance arrangements, and mechanisms for scrutiny of ABS operations, please see ABS Institutional Environment.

Birth statistics published by the ABS are sourced from birth registration systems administered by state and territory Registrars of Births, Deaths and Marriages, based on data provided on a registration form completed by the parent(s) of the child. Registration of births is compulsory in Australia under relevant state/territory legislation.

Birth statistics are one of the components in the production of estimates of natural increase (excess of births over deaths) used as a component of population change in the calculation of population estimates of Australia and the states and territories. The primary uses of population estimates are in the determination of seats in the House of Representatives for each state and territory, as well as in distribution of Australian Government funds to state, territory and local governments. Population estimates are also used for a wide range of government, business and community decisions, both directly and indirectly, by contributing to a range of other social and economic indicators.

Birth statistics are also essential in the analysis of fertility in Australia, and inform on the population's growth and replacement. Trends in fertility are used in the development of assumptions on future levels of fertility for population projections.

Births, Australia contains statistics for births and fertility in Australia. Data refer to births registered during the calendar year shown, unless otherwise stated. Statistics on demographic characteristics of the parent(s) such as age, place of usual residence, marital status, Indigenous status and country of birth are included.

Births data include:

• all live born births registered in Australia that have not been previously registered
• births to temporary visitors to Australia
• births occurring within Australian Territorial waters
• births occurring in Australian Antarctic Territories and other external territories
• births occurring on Norfolk Island from 1 July 2016 are included in this publication. This is due to the introduction of the Norfolk Island Legislation Amendment Act 2015. Norfolk Island births are included in statistics for "Other Territories" as well as totals for all of Australia. Births occurring on Norfolk Island prior to 1 July 2016 were not in scope for birth statistics
• births occurring in transit (i.e. on ships or planes) if registered in the Australian state or territory of 'next port of call'
• births to Australian nationals employed overseas at Australian legations and consular offices (i.e. children born overseas to Australian diplomats or their families)
• births that occurred in earlier years that have not been previously registered (late registrations).
   

Births data exclude:

• still births/fetal deaths (these are accounted for in perinatal death statistics published in Causes of Death, Australia and previously, in Perinatal Deaths, Australia (cat. no. 3304.0))
• adoptions, sex changes, legitimations and corrections
• births to foreign diplomatic staff.
   

Birth records are provided electronically to the ABS by individual state/territory Registrars on a monthly basis for compilation into aggregate statistics on a quarterly and annual basis.

Quarterly estimates of births on a preliminary basis are published five to six months after the reference period in National, state and territory population and revised 21 months after the end of each financial year. Annual estimates on a year of registration basis are generally published within 12 months of the reference year in Births, Australia.

One dimension of timeliness in birth registrations data is the interval between the occurrence and registration of a birth. Some births occurring in one year are not registered until the following year or later. This can be caused by either a delay by the parent(s) in submitting a completed form to the registry, or a delay by the registry in processing the birth (for example, due to follow up activity due to missing information on the form, or resource limitations).

Information on births is obtained from a complete enumeration of births registered during a specified period and is not subject to sampling error. However, births data sources are subject to non-sampling error which can arise from inaccuracies in collecting, recording and processing the data.

Sources of non-sample error include:

• incompleteness of an individual record at a given point in time
• incompleteness of the dataset (e.g. impact of registration lags, processing lags and duplicate records and births that are never registered)
• lack of consistency in the application of questions or forms used by data providers, both through time and between different jurisdictions.
   

Every effort is made to minimise error by working closely with data providers, including supporting the careful design of forms, training of processing staff, and efficient data processing procedures.

The international standards and recommendations for the definition and scope of birth statistics in a vital statistics system are set out in the Principles and Recommendations for a Vital Statistics System Revision 2, published by the United Nations Statistical Division (UNSD). Consistent with the UNSD recommendations, the ABS defines a birth as the complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of pregnancy, which after such separation, breathes or shows any other evidence of life, such as beating of the heart, pulsation of the umbilical cord or definite movement of voluntary muscles, whether or not the umbilical cord has been cut or the placenta is attached; each product of such a birth is considered liveborn. In addition, the UNSD recommends that the births to be counted include all births "occurring in every geographic area and in every population group comprising the national area". For Australia, this includes all births occurring within Australia as defined by the Australian Standard Geographical Classification (ASGC) or Australian Statistical Geography Standard (ASGS) that applies at the time.

Registration of births is compulsory in Australia under relevant state/territory legislation. However, each state/territory Registrar has its own birth registration form. Most data items are collected in all states and territories and therefore statistics at a national level are available for most characteristics. In some cases, different wording of questions asked on the registration form may result in different answers which may affect final figures.

Use of the supporting documentation released with the statistics is important for assessing coherence within the dataset and when comparing the statistics with data from other sources. Changing processes over time and/or across state/territory registries can affect consistency and hence interpretability of statistical output. Explanatory Notes in each issue contain information pertinent to that particular release which may impact on comparison over time.

Data presented in this publication are reported by year of registration (unless otherwise stated) and differ from birth statistics published in National, state and territory population which are reported on a year/quarter of occurrence basis in final and revised data for use in population estimates.

Birth registrations data are not the only statistical series of births in Australia. The National Perinatal Data Collection (NPDC) is a national collection on pregnancy and childbirth, based on births reported to the Perinatal Data Collection in each state and territory in Australia. Midwives and other health professionals who attend births complete notification forms for each birth using information obtained from mothers and hospital or other records. This information is compiled and published annually by the National Perinatal Statistics Unit (NPSU) of The Australian Institute of Health and Welfare (AIHW) in Australia's Mothers and Babies. As information from these two collections are from different sources, the statistics obtained may vary. The number of births in the Perinatal Data Collection is generally greater, which may reflect that the parent(s) delay or fail to register the birth of a child. For more information, see Explanatory notes - Differences Between Collections, in this edition.

Birth statistics are generally straightforward and easy to interpret. It should be noted, however, that changes in numbers of births over time can be due to two factors: changes in fertility, and changes in the number of women in child-bearing ages. For this reason, births data need to be considered in relation to the size of the relevant population(s) through the use of fertility rates.

Another aspect that may be overlooked is plurality, or the fact that each birth of a multiple birth is counted individually in births data. Confinement statistics remove the effect of plurality and are used when analysing characteristics of the mother or father; for example, for calculating median ages.

Information on fertility rates, as well as data sources, terminology, classifications and other technical aspects associated with the statistics presented in this publication can be found in the Explanatory notes, Appendices and Glossary.

Births data are available in a variety of formats on the ABS website under the 3301.0 product family. The formats are:

• Web contents, which contains publication commentary
• ABS.Stat datasets
• data cubes (in Microsoft Excel spreadsheet format).
   

Further information on births and fertility may be available on request. The ABS observes strict confidentiality protocols as required by the Census and Statistics Act (1905). This may restrict access to data at a very detailed level which is sought by some users.

The age-specific fertility rate (ASFR) is the number of live births (registered) during the calendar year, according to the age of the mother, per 1,000 of the female estimated resident population of the same age at 30 June. For calculating these rates, births to mothers under 15 years are included in the 15-19 years age group, and births to mothers aged 50 years and over are included in the 45-49 years age group. Pro rata adjustment is made for births for which the age of the mother is not given.

The birth of a live-born child where at least one parent reports as being an Aboriginal, Torres Strait Islander, or both Aboriginal and Torres Strait Islander Australian on the birth registration form.

The ASGS defines all the regions for which the ABS publishes statistics within the one framework and is used by the ABS for the collection and dissemination of geographically classified statistics from 1 July 2016. It is the current framework for understanding and interpreting the geographical context of statistics released by the ABS.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas, July 2016 (cat. no. 1270.0.55.001).

Baby boom refers to the generation born between the end of World War II and the mid-1960s. Baby boomers are usually taken to be those born in the years 1946 to 1965 inclusive.

The delivery of a child, irrespective of the duration of pregnancy, who, after being born, breathes or shows any evidence of life such as a heartbeat.

See Reproductive lifetime.

Completed fertility represents the average number of births a cohort of females have born over their reproductive lifetimes.

The labour period which results in at least one live birth.

The classification of countries used in the Standard Australian Classification of Countries (SACC).

For more information, please refer to Standard Australian Classification of Countries (SACC) (cat. no. 1269.0).

The crude birth rate is the number of live births registered during the calendar year per 1,000 estimated resident persons at 30 June of that year.

The official measure of the population of Australia is based on the concept of usual residence. It refers to all people, regardless of nationality, citizenship or legal status, who usually live in Australia, with the exception of foreign diplomatic personnel and their families. It includes usual residents who are overseas for less than 12 months over a 16 month period. It excludes overseas visitors who are in Australia for less than 12 months over a 16 month period.

An ex-nuptial birth is the birth of a child whose parents are not registered as married to each other at the time of the child's birth.

Australian external territories include Australian Antarctic Territory, Coral Sea Islands Territory, Territory of Ashmore and Cartier Islands, and Territory of Heard and McDonald Islands.

See Birth.

An ABS approximation of the officially gazetted LGA as defined by each state and territory local government department. LGAs cover incorporated areas of Australia, which are legally designated areas which incorporated local governing bodies have responsibility. The major areas of Australia not administered by incorporated bodies are the northern parts of South Australia and all of the Australian Capital Territory and the Other Territories. These regions are identified as 'Unincorporated' in the ABS LGA structure.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 3 - Non ABS Structures (cat. no. 1270.0.55.003).

Two separate concepts of marital status are measured by the ABS. These are registered marital status and social marital status.

Registered marital status refers to formally registered marriages and divorces. Registered marital status is a person's relationship status in terms of whether he or she has, or has had, a registered marriage with another person. Accordingly, people are classified as either 'never married', 'married', 'widowed' or 'divorced'. Statistics included in this release are based on registered marital status.

The median age of mother at the time of birth measures the median age of females who gave birth in a particular year. This release reports on median age of mother at the time of birth.

For any distribution, the median value (age, duration, interval) is that value which divides the relevant population into two equal parts, half falling below the value, and half exceeding it. Where the value for a particular record has not been stated, that record is excluded from the calculation.

Death.

A multiple birth is a confinement which results in two or more children, at least one of which is live-born.

The net reproduction rate represents the average number of daughters that would be born to a group of females if they are subject to the fertility and mortality rates of a given year during their future life. It indicates the extent to which the population would reproduce itself. The net reproduction rate is obtained by multiplying the age-specific birth rates (for female births only) by the proportion of survivors at corresponding ages in a life table and adding the products.

A nuptial birth is the birth of a child born to parents who are registered as married at the time of the child's birth.

Nuptiality relates to the registered marital status of persons and the events such as marriages, divorces and widowhood. Confinements and births are identified as being nuptial where the registered father was registered as married to the mother at the time of birth, or where the husband died during pregnancy. Confinements and births to Indigenous mothers considered to be tribally married are classified as nuptial. Other confinements, and births resulting from them, are classified as ex-nuptial whether or not both parents were living together at the time of birth.

Following the 1992 amendments to the Acts Interpretation Act 1901-1973 (Cwlth) to include the Indian Ocean Territories of Christmas Island and the Cocos (Keeling) Islands as part of geographic Australia, another category at the state and territory level has been created, known as Other Territories. From 1 July 2016, the Australian Government assumed responsibility for Norfolk Island. Other Territories include Jervis Bay Territory, previously included with the Australian Capital Territory, as well as Christmas Island, the Cocos (Keeling) Islands and Norfolk Island.

Parity refers to the number of live births a woman has had previous to the most recent birth. Parity is also an attribute of any live birth, being the order of that birth (e.g. first birth, second birth, and so on) of a woman.

A paternity acknowledged birth refers to an ex-nuptial birth where paternity was acknowledged (on the birth registration form).

A paternity not acknowledged birth refers to an ex-nuptial birth where paternity was not acknowledged (on the birth registration form).

Previous births refer to children born alive (who may or may not be living) to a mother prior to the registration of the current birth in the processing period. In some states, legitimised and legally adopted children may also be included.

See Previous births.

The Australian Statistical Geography Standard (ASGS) defines Remoteness Areas into 5 classes of relative remoteness across Australia. Each RA is created from the grouping of Statistical Areas Level 1 (SA1) identifying a (non-contiguous) region in Australia having a particular degree of remoteness. The 5 classes of remoteness are: Major Cities, Inner Regional, Outer Regional, Remote, and Very Remote.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 5 - Remoteness Structure (cat. no. 1270.0.55.005).

Replacement level fertility is the number of babies a female would need to have over her reproductive life span to replace herself and her partner. Given the current mortality of females up to age 49 years, replacement fertility is estimated at around 2.1 babies per female.

Women's childbearing years, usually assumed as the ages from 15 to 49 years for the purpose of analysis. In this release, births to women less than 15 years are included in the 15-19 years age group and those 50 years and older are included in the 45-49 years age group.

The number of males per 100 females.

The state or territory in which the event was registered.

The state or territory of usual residence of:

• the population (estimated resident population)
• the mother (birth collection)
• the deceased (death collection).

An area defined in the Australian Statistical Geography Standard designed as the smallest unit for the release of Census data. They generally have a population of 200 to 800 people, and an average population of about 400 people. SA1s in remote and regional areas generally have smaller populations than those in urban areas. There are 57,523 SA1s and they cover the whole of Australia without gaps or overlaps. Births data are not available at this level of geography.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas (cat. no. 1270.0.55.001).

A general-purpose medium-sized area defined in the Australian Statistical Geography Standard and built from whole SA1s. They aim to represent communities that interact together socially and economically. SA2s are based on officially gazetted suburbs and localities. In urban areas, SA2s largely conform to one or more whole suburbs, while in rural areas they generally define the functional zone of a regional centre. SA2s generally have a population range of 3,000 to 25,000 people, and an average population of about 10,000 people. There are 2,310 SA2s and they cover the whole of Australia without gaps or overlaps. SA2s are the base unit for preparing sub-state fertility statistics.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas (cat. no. 1270.0.55.001).

An area defined in the Australian Statistical Geography Standard and built up from SA2s, which provides a standardised regional breakup of Australia. SA3s aim to create a standard framework for the analysis of ABS data at the regional level through clustering groups of whole SA2s that have similar regional characteristics. Their boundaries reflect a combination of widely recognised informal regions as well as existing administrative regions such as State Government Regions in rural areas, and Local Government Areas in urban areas. SA3s generally range in population from 30,000 to 130,000 people. There are 358 SA3s and they cover the whole of Australia without gaps or overlaps.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas (cat. no. 1270.0.55.001).

An area defined in the Australian Statistical Geography Standard, designed for the output of labour force data and to reflect labour markets. In rural areas, SA4s generally represent aggregations of multiple small labour markets with socioeconomic connections or similar industry characteristics. Large regional city labour markets are generally defined by a single SA4. Within major metropolitan labour markets SA4s represent sub-labour markets. SA4s are built from whole SA3s. They generally have a population over 100,000 people to enable accurate labour force survey data to be generated. There are 107 SA4s and they cover the whole of Australia without gaps or overlaps.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas (cat. no. 1270.0.55.001).

The number of births during the calendar year to women aged 15-19 years, per 1,000 females of the estimated resident population aged 15-19 years at 30 June of the same year. Births to women aged under 15 years are included.

The sum of age-specific fertility rates (live births at each age of mother per 1,000 females of the estimated resident population of that age) divided by 1,000. It represents the number of children a female would bear during her lifetime if she experienced current age-specific fertility rates at each age of her reproductive life.

Usual residence within Australia refers to that address at which the person has lived or intends to live for a total of six months or more in a given reference year.

The year the birth occurred.

The year the birth was registered.

Birth registrations data in this publication are not the only births data available in Australia. The Australian Institute of Health and Welfare (AIHW) also collects birth data from midwives and other health professionals who attend births. These data are published annually in Australia's Mothers and Babies.

As information from these two collections are from different sources, the number of live births may differ. Births from the AIHW National Perinatal Data Collection are released on a year of occurrence basis, while registered births from the ABS Birth Registrations collection are predominantly released on a year of registration basis. The AIHW National Perinatal Data Collection reported the occurrence of 303,029 live births in Australia in 2018 (the latest available data), 4% less than the 315,147 births registered in the same year. Since 2002 the size of the difference between the two collections has varied between -2.6% and 4%.