Table 13 presents live births by legitimacy status, and per cent illegitimate for as many years as possible between 1990 and 1998.
Description of variables: Legitimacy status in this table is shown as legitimate, illegitimate and of unknown status.
Legitimate refers to persons born of parents who were married at the time of birth in accordance with the laws of the country or area. Illegitimate refers to children of parents who according to national law, were not married at the time of birth, regardless of whether these children have been recognized or legitimized after birth.
Therefore, illegitimate births (unless otherwise noted) are assumed to include births to persons in consensual unions or in unions celebrated in a manner other than the legally prescribed one as, for example, by a religious ceremony instead of the prescribed civil contract. Within this context, they include all extra-nuptial live births, whether they are births of foundlings (children acknowledged by no parent), children acknowledged or recognized by both their father and mother or those acknowledged by their mother only.
Births of unknown legitimacy status are assumed to be illegitimate.
Percentage computation: The percentage illegitimate is the ratio of the number of illegitimate live births, in a year, including those of unknown legitimacy status, per 100 total live births shown for the same year.
Reliability of data: Data from civil registers of live births which are reported as incomplete (less than 90 per cent completeness) or of unknown completeness are considered unreliable and are set in italics rather than in roman type. Table 1 and the technical notes for that table provide more detailed information on the completeness of live-birth registration. For more information about the quality of vital statistics data in general, and the information available on the basis of the completeness estimates in particular, see section 4.2 of the Technical Notes.
Limitations: Statistics on live births by legitimacy status are subject to the same qualifications which have been set forth for vital statistics in general and birth statistics in particular as discussed in section 4 of the Technical Notes.
The reliability of the data, on indication of which is described in the above paragraph, is an important factor in considering the limitations. In addition, some live births are tabulated by date of registration and not by date of occurrence, these have been indicated by a (+). Whenever the lag between the date of occurrence and date of registration is prolonged and, therefore, a large proportion of the live-birth registrations are delayed, birth statistics for any given year may be seriously affected.
Another factor that limits international comparability is the practice of some countries or areas not to include in live-birth statistics infants who were born alive but died before registration or within the first 24 hours of live, thus underestimating the total number of live births. Statistics of this type are footnoted.
Comparability of illegitimacy ratios is affected by differences between countries in the legal definition of illegitimacy. In most countries or areas, illegitimate births are only those born to unmarried mothers; children born of a married woman and a person other than her husband are considered issue of the legal union and hence legitimate. However, in a few cases such children are reported as illegitimate.
There is also a difference between countries or areas in the reference date for definitions of illegitimacy. In some countries or areas, the marital status of the parents at the time of the child’s birth determines the status of legitimacy; in others, the effective status is that at the time the birth is registered.
As has been noted in connection with the tables on total live births, there may be a delay between time of birth and registration of birth. In cases in which there is a time delay, it is possible that the legitimacy status of the child may change before registration of his or her birth. This factor may limit comparability.
The type of union that establishes legitimacy also differs from one country or area to another. In most countries or areas religious marriage is not considered legal unless it is accompanied by a civil ceremony. Hence, children born to persons who have not complied with the civil requirements would be considered illegitimate by law, even though the marriage of their parents was accepted socially.
The same problem exists in countries or areas where consensual unions are more socially accepted. Where such unions are numerous in relation to legal marriages (because of either social or tribal custom or other reasons), the proportion of “illegitimate births” will also be high in relation to total births.
Also, another problem exists where live-births by age of mother or live-birth order are only presented for legitimate live-birth, rather than total live-births. In such countries or areas, the changing distribution of live-births by age of mother or live-birth order will not accurately reflect overall changes in the pattern of childbearing, especially if the ratio of legitimate and illegitimate births changes during the time period.
Comparability of illegitimacy statistics is also affected by national attitudes towards illegitimacy. Decision to conceal illegitimacy or to misstate it on the record is conditioned by attitudes in the society in which the mother lives and also by her economic and social circumstances within the society. The impact of these factors is very difficult to quantify, but it must be borne in mind when data from this table are used for analytical purposes.
Finally, it should be noted that rates may be affected by the number of births included for which the presumption of legitimacy status has been made. In preparing this table the presumption of illegitimacy for cases of unknown legitimacy status has been based on the fact that the place showing high frequencies of “unknowns” are those in which there are large numbers of consensual unions, and it is assumed that the “unknowns” are related to this segment of the population. The absence of frequencies in the unknown legitimacy status group does not necessarily indicate completely accurate reporting and tabulation of legitimacy status. It could be the case that unknowns have been eliminated by assigning them legitimacy status before tabulation.
Coverage: Live births by legitimacy status and per cent illegitimate are shown for countries or areas.
Earlier data: Live births by legitimacy status and per cent illegitimate have been shown previously in issues of the Demographic Yearbook featuring natality. For information on years covered, readers should consult the Index.
 Principles and Recommendations for a Vital Statistics System Revision 2, United Nations Publication, Sales No. E.01.XVII.10, Para.132-136, New York, 2001.