demographic yearbook annuaire demographique 1951

Table 8 presents for 33 areas birth rates specific for age
of mother. These data refer to the period 1936-1949 and
were derived from statistics of births classified by age of
mother and statistics of the female population classified by
age. For these computations, births to mothers of unknown
age were distributed proportionately among births to mothers
of known age. The rate is the number of live births to
mothers in a specified group (adjusted to include the
unknown) per 1,000 women of that age group. Population
of unknown age does not enter into the computation, as the
birth rate for "all ages" shown in this table is an age-limited
rate, including births at all ages, but based on the female
population 10 to 49 years old. The rates for the initial and
terminal groups are based on the population 10 to 14 and
45 to 49 respectively, since only a negligible fraction of all
births occur among women under 10 or over 50 years of age.
The totals on which the rates are based do not always
agree with the totals shown in table 6, chiefly because of
differences in the basis of tabulation. These differences have
some bearing on the comparability of the data. For example,
certain countries tabulate only legitimate births by age of
mother. Where illegitimate births are relatively numerous,
the data cannot be taken as representative. Similarly, the
distribution of births by age of mother for a few countries
is confined to infants born alive who did not die before
registration, whereas the totals in table 6 include those who
died before registration. Again, the figures given by age
in certain instances refer to deliveries or confinements rather
than to births, in some cases confinements resulting in live
births only, in others confinements resulting in live-born
or stillborn offspring.
Table 9 presents birth rates by order of birth, or parity,
for 23 areas during the period 1936 to 1949. The rate is
the number of births of each birth order per 1,000 women
aged 10 to 49 years. The rate for all birth orders combined
is therefore the same as that shown in table 8 for all ages
combined, except where the data are affected by differences
in coverage. Such differences are explained in the table
notes. Orders from the first to the ninth are shown separately;
the tenth and higher are grouped together.
As in the preceding table, comparability of these data is
limited by differences in treatment of illegitimate births,
multiple births and stillbirths. The principal limiting factor,
however, is that involved in the method used for establishing
birth order. Some countries base the calculation on the
number of previous live births, others on the number of live
births and stillbirths or on the number of confinements
(sometimes including confinements resulting in stillbirths).
In certain countries parity is calculated on the basis of previous
legitimate births only, and in some instances on the
basis of only those legitimate births that occurred during
the existing marriage of the mother. Whenever such limitations
are known, they are stated in footnotes to the table.
STILLBIRTH STATISTICS
Table 10 and table 11 present statistics of stillbirths for the
years 1935 to 1950. These data are subject to severe limitations
with respect to completeness and comparability. Areas
that are known to have generally deficient or irregular vital
registration are indicated in footnotes, but it should be
understood that many countries with relatively adequate
statistics of live births and deaths may have quite inadequate
stillbirth statistics. It would appear that even with a highly
efficient registration system a considerably greater propor-
tion of stillbirths than of live births or of deaths escapes
registration. However, it is difficult to measure or estimate
just what fraction of the total number occurring go unregistered.
Consequently, no precise information on completeness
of coverage is available. Perhaps the most that can be said
is that the coverage of stillbirths in countries where most of
the births occur in hospitals is more complete than in others.
The comparability of stillbirth statistics is strongly affected
by differences in definition, as well as by variations in completeness
of coverage. A stillbirth is generally understood to
be the birth of a viable foetus that shows no signs of life
after delivery. As has already been indicated, certain countries
classify live-born infants dying shortly after birth
("within 24 hours", "immediately", "before registration as
a live birth" etc.) as stillbirths. The relatively few countries
that are known to follow these practices are noted in the
tables. Again, some countries do not consider viability but
classify all foetuses which are reported to have been born
without life as stillbirths. Still further variations arise from
differences in specifications as to what may be accepted as
"signs of life".
Criteria of viability are usually based on the duration of
pregnancy, meaured in days, weeks or months. The minimum
period of gestation specified varies widely, ranging,
according to available information, from 3 to 7 months.
The interval most frequently specified as the minimum is
28 weeks. Some countries have an additional requirement
that the foetus be a minimum length, the minimum specified
ranging from 30 to 35 centimetres. In a number of cases the
only specification is simply that the foetus must be viable
or that it must be recognizable as a human being.
Although full information on how stillbirths are defined
could not be obtained for all the areas and years for which
stillbirth data are shown in this volume, some information
on current practices is available for most of the areas and is
summarized below.
I. Areas specifying a minimum period of gestation:
A. 28 weeks (or 7 months, as indicated)
Africa:
Asia:
Gold Coast [U.K.] Ceylon
Mauritius [U.K.] Federation of Malaya
(7 months) India (some Provinces)
Thailand
America, North:
British Honduras
Canada
Canal Zone [U.S.]
Costa Rica
Dominican Republic
Guatemala
Honduras
Mexico
Trinidad and Tobago
[U.K.]
America, South:
Bolivia
British Guiana
Chile (beginning
1944)
Ecuador (beginning
1945)
Paraguay
Peru
Europe:
Bulgaria
Denmark
Hungary
Iceland
Netherlands (beginning
1950)
Norway
Romania (6Yz months)
Sweden
United Kingdom:
England and
Wales
Scotland
Yugoslavia
Oceania:
New Zealand
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