A. Live birth (para. 57.)

Live birth is 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 (all live-born infants should be registered and counted as such, irrespective of gestational age or whether alive or dead at the time of registration, and if they die at any time following birth they should also be registered and counted as deaths).

B. Foetal death (para. 57.)

Foetal death [deadborn foetus] is death prior to the complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of pregnancy; the death is indicated by the fact that after such separation the foetus does not breath or show any other evidence of life, such as beating of the heart, pulsation of the umbilical cord or definite movement of voluntary muscles (note that this definition broadly includes all terminations of pregnancy other than live births, as defined above).

C. Children ever born (paras. 2.126.- 2.131.)

Information on number of children born alive (lifetime fertility) should include all children born alive (that is to say, excluding foetal deaths) during the lifetime of the woman concerned up to the census or survey date. The number recorded should include all live-born children, whether born in or out of marriage, whether born in the present or a prior marriage, or in a de facto union , or whether living or dead at the time of the census.

Data on the total number of live-born children should preferably be collected for all women 15 years of age and over, regardless of marital status. If, from a cultural standpoint, it is not feasible in some countries to obtain the information for single women, it should be collected at least for all women 15 years of age and over who are or have been married (in other words, all ever-married women), a group also including all widowed, divorced and separated women. In either case, the group of women for whom the data have been collected should be clearly described in the census report so as to avoid ambiguity in the analysis of the results. In some countries, there is substantial age-misreporting in the population census, which distorts fertility and mortality estimation based on children ever born and children living cross-tabulated by age of the woman.

Information on "total number of children ever born alive by sex" provides data on the lifetime fertility of each woman, which is used for the estimation of age-specific fertility rates and other fertility indicators. Furthermore, information on "total number of children living (surviving) specified by sex" is used for the indirect estimation of sex differentials in infant and child mortality in combination with data on children ever born alive by sex.

D. Children living (paras. 2.132.- 2.133.)

Research has suggested that improved coverage and quality of data on the total number of children ever born will be achieved if more detailed questions about the current residence of children ever born are asked, in terms of the following:

These questions not only give a more complete and accurate reporting of children ever born alive specified by sex but also increase the questions’ suitability for subsequent analysis.

The identification of the natural mother of each child under 15 years of age in the same household, to be used in the "own children" method of estimating fertility, should be made by asking each woman who reports one or more of her children as being born alive and living in the household to identify these children in the census questionnaire. The section of the questionnaire on "relationship to the head of the household or to the reference person in the household" may be used for identifying the natural mother of each child living in the household.

E. Date of birth of last child born alive (paras. 2.134.- 2.136.)

Information on date of birth (day, month and year) of the last child born alive and on the sex of the child is used for estimating current fertility. Later, at the processing stage, “the number of children born alive in the 12 months immediately preceding the census date” can be derived as an estimate of live births in the last 12 months. For estimating current age-specific fertility rates and other fertility measures, the data provided by this approach are more accurate than information on the number of births to a woman during the 12 months immediately preceding the census.

It should be noted that information on the date of birth of the last child born alive does not produce data on the total number of children born alive during the 12-month period. Even if there are no errors in reporting of the data on the last live-born child, this item ascertains the number of women who had at least one live-born child during the 12-month period, not the number of births, since a small proportion of women will have had more than one child in a year.

F. Age of mother at birth of first child ever born (para. 2.143.)

Age of mother at the time of the birth of her first liveborn child is used for the indirect estimation of fertility based on first births and to provide information on onset of childbearing. If the topic is included in the census, information should be obtained for each woman who has had at least one child born alive.