Table 17 presents late foetal deaths ratios specific for age of mother for as many years as possible between 1990 and 1998.
Description of variables: Late foetal deaths are foetal deaths of 28 or more completed weeks of gestational age. Foetal deaths of unknown gestational age are included with those of 28 or more weeks.
Age is identified 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 complete solar years. The age classification used in this table is the following: under 20 years, 5-year age groups through 40-44 years, and 45 years and over.
computation: Late foetal death ratios specific for age of mother are the number
of late foetal deaths in each age group of mother (as shown in table 16) per
foetal deaths to mothers of unknown age are 10 per cent or more of the total,
then ratios are not computed.
Ratios presented in this table have also been limited to those countries
or areas having at least a total of
Reliability of data: Data from civil registers of late foetal deaths 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 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: The ratios shown in this table are subject to the same limitations which affect the numerators and denominators used in their computation. These limitations are described in the technical notes for tables 16 and 4 respectively.
In addition, some idea of the relative reliability of the late foetal-death and live-birth components may be gained by examining the ratios. When both components of the ratios are of approximately equal reliability in terms of completeness and of age-reporting accuracy, the ratios will increase uniformly with increasing age. If, on the other hand, live births are more completely registered than late foetal deaths, the ratios may show no systematic increase with age, but rather, discontinuities and even decreases. Ratios for several countries or areas exemplify this tendency.
Furthermore, in countries or areas where infants dying before registration of birth or within the first 24 hours after birth are included with late foetal deaths instead of with live births, the resultant ratios are artificially inflated. Such cases are footnoted in the table.
Coverage: Late foetal death ratios specific for age of mother are shown for 21 countries or areas.
Earlier data: Late foetal death ratios specific for age of mother have been shown previously in issues of the Demographic Yearbook featuring natality. For information on years covered, readers should consult the Index.
 For definition, see section 188.8.131.52 of the Technical Notes.