Definition

Children ever born (CEB) to women in a particular age group is the mean number of children born alive to women in that age group. The number of children ever born to a particular woman is a measure of her lifetime fertility experience up to the moment at which the data are collected. The following seven five-year age groups by age of women at the moment at which the data are collected are presented in the data base: 15 to 19; 20 to 24; 25 to 29; 30 to 34; 35 to 39; 40 to 44; and 45 to 49.

In most cases, the mean number of children ever born is computed as the ratio of the number of children born alive to all women in a particular age group to the number of women. In cases where the total number of children born to women in the age group is not provided but a tabulation is available on the distribution of women by age group and number of children ever born, the mean number of children ever born to women in the age group is obtained as:

Where j is the number of children and Pj is the proportion of women in that age group who have given birth to a total of j children.

Data sources

Data on children ever born can be obtained from censuses or sample surveys from questions regarding the number of children born alive to each woman. The availability of survey and census data depends on the existence of adequate survey or census programmes in a country or area. Censuses are generally conducted every 10 years. Surveys are undertaken at different intervals in different countries. In developing countries they typically take place every three to five years.

For censuses, preference is given to data reported by national statistical offices to the United Nations Statistics Division. Data are also taken from census reports and other analytical publications produced by national statistics offices. The latter are preferred when data on CEB compiled by the United Nations Statistics Division refer to a restricted age range or category of women (such as ever-married or currently married women) and more detailed information is available from national sources.

For surveys, whenever the estimates are available in the survey report they are directly taken from the report. The main surveys utilized are the Demographic and Health Surveys (DHS), the Reproductive Health Surveys (RHS), the World Fertility Survey (WFS), the Multiple Indicator Cluster Surveys (MICS), the Contraceptive Prevalence Surveys (CPS), and other nationally sponsored surveys.

Data on children ever born can be also obtained from cohort fertility life tables, generally computed from data on births by age of mother from civil registration systems and female population by age and number of children ever born from censuses, where each cohort of women is followed for the whole period of their reproductive life. Cohort fertility life tables are available for a number of countries in developed regions.  For data and documentation see:

Human Fertility Database. Max Planck Institute for Demographic Research (Germany) and Vienna Institute of Demography (Austria). Available at www.humanfertility.org

Criteria for data source selection

Generally, only one source is provided per year for a country. When more than one source is available for the same period, precedence is given to estimates based on censuses. However, where such estimates are unavailable or incomplete, survey estimates or estimates from the Human Fertility Database are used. In countries with multiple survey programmes, sample surveys conducted on an annual or biennial basis are used where they exist.

For each data point, information is provided on the source type (census or survey) and the source (usually denoted by an acronym). A description of each acronym is given in the data file in the worksheet labeled "Sources". For surveys, the full name is provided in the field "Survey name".

Comments and limitations

Data on children ever born for successive age groups of women of post-reproductive age (aged 45 or over) provide information about trends in completed cohort fertility to the extent that the women providing the information are not very different in their fertility behaviour from the original birth cohort (that is, provided that death and migration have a minor effect on the estimates), and provided that omission of children who have died is not a serious problem. The mean number of children ever born to women currently aged 15 to 19 years and women aged 20 to 24 years are useful summary measures of the timing of onset of fertility.

In some countries, particularly where childbearing is uncommon outside of marriage, data on children ever born are only available for ever-married women or (more rarely) for currently married women. For purposes of comparability, these figures have been converted to figures corresponding to all women by multiplying the corresponding mean number of children ever born by the proportion of ever-married or currently married women in that age group. Notes in the data file are employed to indicate such cases.

In World Fertility Data 2012, El-Badry corrected estimates are used when reported by the national statistical office. For more information on the methodology, see: United Nations (1983). Manual X: Indirect Techniques for Demographic Estimation (United Nations publication, Sales No. E.83.XIII.2), annex II.

Discrepancies between data presented in World Fertility Data 2012 and other estimates

Generally, there is no discrepancy between estimates presented in World Fertility Data 2012 and data on children ever born reported by national statistical systems. There is no attempt to provide estimates when country data are not available from published reports.

Estimates of children ever born reported in World Fertility Data 2012, however, may differ from those reported by the United Nations Statistics Division and published in the Demographic Yearbook due to the treatment of the nonresponse category.   

Data coverage  

World Fertility Data 2012 contains 872 data points on children ever born for 218 countries or areas of the world. Data are provided, where available, for five different reference dates: the years closest to 1970, 1985 and 1995, 2005 and the most recent data available. Data are available for five reference dates for 115 countries or areas. The data base presents data available as of October 2012.