Las Fronteras de la Ilusión y el progreso indefinido de la ciencia y la tecnología

and months.

The applicability of the suggested procedures for adjusting fertility

rates derived from pregnancy histories were discussed in the context of

Bangladesh (Chapter 3). Brass's (1971, 1975) first birth procedure, which

uses the distribution of first births in the 0-4 years before the survey as the

standard for adjusting all order births, might not be applicable in the case

of Bangladesh because of the possible effects of the 1971 war of liberation

and the 1974 famine on fertility in the 0-4 years preceding the survey. It

has also been demonstrated by Potter (1977a : 347) that Brass's first birth

procedure would not be effective for detecting and adjusting fertility rates

the reporting of first births are not the same as those for all order births. Brass and Rashad (1980) have applied the P/F ratio method and the

Gompertz relational model for adjusting the observed fertility rates derived

by using the pregnancy history data from the Bangladesh Fertility Survey, 1975-76. They have found the adjusted total fertility rates for the period 1971-75 to be about 7.5 and 7.4 using the P/F ratio method and the Gompertz relational model respectively. The national estimate of total fertility of 5.9 derived in the present study during the period 1971-75, which has closely agreed with the corresponding estimate obtained by Rodriguez and Cleland (1980 : 23), has been about 25-27 per cent lower than the adjusted estimate during the same period. Brass (1980 : 20) was also doubtful about the levels of fertility during the period 1971-75 as found by the application of the adjustment procedures.

Infant mortality rates have shown, in general, a downward trend during the period 1955-69. A temporary halt in the declining trend in infant mortality was observed during the period 1970-73. The devastating cyclone in 1970 and the liberation war in 1971 might have been the reasons for the temporary rise in infant mortality. Available evidence has demonstrated a further rise in infant mortality in the year 1974 associated with the crop failure due to

monsoon floods (Chapter 4). A comparison of infant mortality rates from various sources revealed that these rates based on the survival of birth cohorts from pregnancy history data in the early 1970's were lower than the corresponding estimates obtained by the Brass technique based on the survival of children ever born. Infant mortality rates from pregnancy history data are suspected to be under-reported by at least 10 per cent in the 5 year period preceding the survey (Bogue and Bogue, 1980 : 154). The levels of infant mortality per thousand live births in the early 1970's as found in different studies using the Brass technique ranged from 152 to 158. The national estimate of infant mortality of 139 during the period 1970-73 derived in this study was about

9 to 14 per cent lower as compared to the Brass estimates. Nevertheless, the estimates found in the present study closely agreed with the corresponding

estimates derived by Arriaga (1980) from the pregnancy history data (Chapter 4). Although childhood mortality rates between birth and exact age 5 have, in general, shown a declining trend during the period 1955-69, the corresponding rates for children aged 1-4 have not demonstrated such a crend except for the urban areas. The national and rural estimates of 4^1 in the period 1960-64 appeared to be somewhat lower than what would be expected. The national

estimate of childhood mortality between birth and exact age 5 of 0.208 during the period 1965-69 was also about 6 to 13 per cent lower than the corresponding estimates obtained in other studies using the different methods of estimation

(see Chapter 4). The 5*^0 estimates are influenced by the risks of dying under exact age 1 and, as mentioned above, infant mortality rates from pregnancy history data are under-estimated. These might be the reasons for the

apparent lower 5^o estimates derived in the present study during the period 1965-69.

Infant and childhood mortality were generally found to be lower in urban areas than in rural areas. This presumably has reflected the better health and medical facilities in urban areas. Infant mortality was found to be generally higher for males than for females. This has demonstrated the universally higher biological risks of male death in infancy. 5^o estimates also have shown such a sex differential. On the other hand, mortality of children aged 1-4 was found to be generally higher for females than for males. Higher female than male mortality of children between ages 1 and 4 was found in a number of South Asian countries (Chapter 4).

Finally, it was realised that the pregnancy history data used in this

study were not well-reported and well-imputed. This has caused some distortions in the levels and trends in fertility and childhood mortality. Nevertheless,

this study has provided a fair idea about the levels and trends in fertility and childhood mortality in Bangladesh. It may be suggested that in a country like Bangladesh, where a vast majority of women (respondents) are not calendar year conscious and even ignorant of their dates of birth, the pregnancy history data should be carefully edited for any discrepancies before analysis.

It may also be suggested that the analysis of fertility and childhood mortality from pregnancy history data, for a developing country like Bangladesh should not extend beyond the 15 years before the date of survey. Further research should be carried out to study the possible effects and interactions of various response errors on the estimates of fertility and childhood mortality.