Table
18
Table 18
presents late foetal deaths by age of mother and total-birth order for as many
years as possible between 1990 and 1998.
Descriptions of
variables: Late foetal deaths are foetal deaths[1]
of 28 or more complete weeks of gestation.
Foetal deaths of unknown gestational age are included with those of 28 or
more weeks.
Age of
mother is defined as age at last birthday, that is the difference between the
date of birth and the date of the occurrence of the event, expressed in
completed solar years. The age
classification used in this table is the following less than 15 years, 5-year
age groups through 40-44 years, 45 years and over and age unknown.
Total
birth order is defined as the numerical order of the late foetal deaths being
recorded, in relation to all previous issue of the mother, irrespective of
whether the issue was live-born or born dead (foetal death), or whether
pregnancies were nuptial or extra-nuptial[2].
Except where otherwise indicated 11 categories are used to classify total-birth
order: 1 through 9, 10 or more total births and unknown.
Reliability of
data: Data from civil registers of late foetal deaths which are reported as
incomplete (less than 90 per cent completeness are considered unreliable and are
set in italics rather than in roman type.
Table 15 and the technical notes for that table provide more detailed
information on the completeness of late foetal death registration. For more information about the quality
of vital statistics 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 late foetal deaths by age of mother and total birth-order are
subject to the same qualifications as have been set forth for vital statistics
in general and foetal-death statistics in particular as discussed in section 4
of the Technical Notes.
The
reliability of data, an indication of which is described in the above paragraph,
is a very important factor. Of all
vital statistics, the registration of foetal deaths is probably the most
incomplete.
Variation in the definition of foetal deaths, and in
particular late foetal deaths, also limits international comparability. The criterion of 28 or more completed
weeks of gestation to distinguish late foetal deaths is not universally used;
some countries or areas use different lengths of gestation or other criteria
such as length of the foetus. In
addition, the difficulty of accurately determining gestational age further
reduces comparability.
Another
factor introducing variation in the definition of late foetal deaths is the
practice by some countries or areas to consider infants who died before the
registration of birth or within the first 24 hours of live as foetal deaths
instead of live births, thus overestimating the total number of late foetal
deaths. Statistics of this type are
footnoted.
As in
other age distributions, lack of frequencies in the unknown-age-of-mother
category is not necessarily an indication of accurate age reporting. In some cases, late foetal deaths for
which age of mother was unknown were distributed among known age frequencies
before tabulation; in others, marked decreases in the frequencies in the unknown
order of late foetal deaths are usually correlated with small frequencies of
first birth order. This may be due
to failure to record a reply to the question when the response is “none”. This same problem appears in data on
women by number of children ever born.
Reporting
errors are another possibility to be borne in mind in using these data. For example very large numbers of births
reported at high birth orders and young ages of mother are not credible; these
are probably due to age-reporting errors.
Coverage: Late
foetal deaths by age of mother and total birth-order are shown for 50 countries
or areas.
Earlier data:
Late foetal deaths by age of mother and total-birth order have been shown
previously in issues of the Demographic yearbook featuring natality. For information on years covered,
readers should consult the Index.