Table 10 presents live births by plurality for as many years as possible between 1990 and 1998.
Description of variables: Plurality in this table refers to the single or multiple nature of the issue of a pregnancy resulting in live birth. The classifications shown here consist of single, twin and other. Other refers to live births of triplets, quadruplets, etc.
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 birth by plurality 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, an 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 which 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 life, thus underestimating the total number of live births. Statistics of this type are footnoted.
In addition, some countries or areas may report not live births but confinements (deliveries) classified by type of issue. The number of confinements is the same as the number of live births in the case of single live births, but in the case of plural issue, the number of confinements is less than the number of live births. Because of this, statistics referring to live births are not comparable to those for confinements.
Coverage: Live births by plurality are shown for 82 countries or areas.
Earlier data: Live births by plurality have been shown previously in issues of the Demographic Yearbook featuring natality. For information on the years covered, readers should consult the Index.