Changes in fertility patterns can improve child survival in Southeast Asia

This analysis of 1988 Philippine Demographic Survey data provides information on the direct and indirect effects of several major determinants of childhood mortality in the Philippines. Data are compared to rates in Indonesia and Thailand. The odds of infant mortality in the Philippines are reduced by 39% by spacing children more than two years apart. This finding is significant because infant mortality rates have not declined over the past 20 years. Child survival is related to the number of children in the family, the spacing of the children, the mother's age and education, and the risks of malnutrition and infection. Directs effects on child survival are related to infant survival status of the preceding child and the length of the preceding birth interval, while key indirect or background variables are maternal age and education, birth order, and place of residence. The two-stage causation model is tested with data on 13,716 ever married women aged 15-49 years and 20,015 index children born between January 1977 and February 1987. Results in the Philippine confirm that maternal age, birth order, mortality of the previous child, and maternal education are directly related to birth interval, while mortality of the previous child, birth order, and maternal educational status are directly related to infant mortality. Thailand, Indonesia, and the Philippines all show similar explanatory factors that directly influence infant mortality. The survival status of the preceding child is the most important predictor in all three countries and is particularly strong in Thailand. This factor acts through the limited time interval for rejuvenation of mother's body, nutritional deficiencies, and transmission of infectious disease among siblings. The conclusion is that poor environmental conditions increase vulnerability to illness and death. There are 133% greater odds of having a short birth interval among young urban women than among older rural women. There is a 29% increase in odds for second parity births compared to third or higher order parities. Maternal education is a strong predictor of infant survival only in the Philippines and Indonesia. Adolescent pregnancy is a risk only in Indonesia. Socioeconomic factors are not as important as birth interval, birth order, and maternal education in determining survival status.     

The Effects of the Registration System on the Seasonality of Births: The Case of the Soviet Union

Scientists study seasonality in order to understand the effect of environmental, biological, and social factors on demographic events. Poor data quality can also affect seasonal variation in mortality and fertility statistics. The influence of error on seasonal data becomes crucial as researchers analyze timing and spacing of events in time-series analyses. In this study we examine the reported number of births by month in the Soviet Union for 1950, 1955, and 1958–85. The lowest number of births has typically occurred in December, and the highest in January. This seasonal pattern is not consistent with any plausible biological or behavioural explanation. It is probably an artifact of attributing births that actually occurred during the preceding December or earlier, to January. This implies that Soviet statistical practice has not followed the stated policy of attributing births to the period (day, month, year) in which they occur. A substantial reduction between the 1950s and 1985 in the December-January peak in reported births implies marked improvement in Soviet vital registration statistics. The Soviet case shows that characteristics of the registration system can impart a particular seasonal pattern to demographic data. It also shows that officially prescribed procedures are not always followed in data generation, even in centrally planned economies. Researchers should carefully examine the quality of seasonal data before concluding that the data reflect real variations in demographic behaviour.     

Malthus in the Bedroom: Birth Spacing as Birth Control in Pre-Transition England

We use duration models on a well-known historical data set of more than 15,000 families and 60,000 births in England for the period 1540–1850 to show that the sampled families adjusted the timing of their births in accordance with the economic conditions as well as their stock of dependent children. The effects were larger among the lower socioeconomic ranks. Our findings on the existence of parity-dependent as well as parity-independent birth spacing in England are consistent with the growing evidence that marital birth control was present in pre-transitional populations.     

Demographic Determinants of Infant and Early Child Mortality: A Comparative Analysis

In this paper we examine the relative importance of a number of demographic determinants of infant and early child mortality using information from 39 World Fertility Survey countries. We include sex of the child, age of the mother at the time of the birth, birth order, mother's educational level and a number of indicators of spacing of adjacent births among the correlates of chances of survival for children below the age of five years. Mortality of firstborn children and of those born to teenage mothers is shown to be higher than average; that of later children and those of older mothers was not much higher than average, once other factors are controlled. Effects of poor birth-spacing persist even after other factors have been controlled, and are similar where a sib was born during the two years preceding the birth of the child, regardless of the survival status of that sib; however, mortality was higher when that sib had died, due to increased familial risks of mortality. Rapid subsequent births also raise mortality for their earlier sibs. The findings are generally remarkably consistent in a wide range of countries and associated mortality conditions, although attention is drawn to a few interesting geographically clustered exceptions which deserve further investigation. The study leaves little room for doubt that poor child-spacing is clearly linked to decreased survival chances.     

The influence of child spacing on child survival

Summary This study evaluates the strength of the influence of spacing on child survival. Data related to a traditional culture (Punjab) in which almost all children are breast-fed up to the age of 17 months. An initial pregnancy history survey, subsequent four years updating through continuous monitoring of vital events and a second cross-sectional pregnancy history survey at the mid-point provided a file containing information on pregnancies and survival of children of 5,018 women. The analysis first looks at the correlation between the lengths of the preceding and subsequent intervals of index children, then examines whether this correlation was related to the repeated pattern of child death or survival. Next, the influence of the duration of the preceding interval on the survival of the index child in general and after accounting for the fate of the preceding child were considered. Then the influence of the length of the subsequent interval on the survival of the index child after conception and after the birth of the next child were studied. Lastly, regression analyses with preceding and subsequent intervals as independent variables and age-specific survival or death as the dependent variable were performed.     

Factors associated with the timing and duration of the leaving-home stage of the family life cycle

Summary Based on empirical age distributions of sons and daughters leaving home, an examination is made of the theoretical effect of three factors - the sex composition of the family, the interval between births, and their reasons for leaving home - on the dynamics of the leaving-home stage in the life cycle of two-child families. Consideration is given to four measures, the timing of the beginning and end of the leaving-home stage, its duration, and the ratio of the length of the leaving-home stage to the length of the childbearing stage. The outstanding feature of the leaving-home stage is that a second child may leave home before its older sibling, described as the 'crossing-over effect'. For Australian data, factors contributing to the variation in experience between families include the fact that sons generally leave home at an older age than daughters, and that children leaving home for different reasons leave at different ages. Brief reference is made to the relationship between the leaving-home stage and the starting-work stage, and to the limitations of a theoretical analysis.     

Birth spacing and fertility limitation: a behavioral analysis of a nineteenth century frontier population

Our analysis of changing birth interval distributions over the course of a fertility transition from natural to controlled fertility has examined three closely related propositions. First, within both natural fertility populations (identified at the aggregate level) and cohorts following the onset of fertility limitation, we hypothesized that substantial groups of women with long birth intervals across the individually specified childbearing careers could be identified. That is, even during periods when fertility behavior at the aggregate level is consistent with a natural fertility regime, birth intervals at all parities are inversely related to completed family size. Our tabular analysis enables us to conclude that birth spacing patterns are parity dependent; there is stability in CEB-parity specific mean and birth interval variance over the entire transition. Our evidence does not suggest that the early group of women limiting and spacing births was marked by infecundity. Secondly, the transition appears to be associated with an increasingly larger proportion of women shifting to the same spacing schedules associated with smaller families in earlier cohorts. Thirdly, variations in birth spacing by age of marriage indicate that changes in birth intervals over time are at least indirectly associated with age of marriage, indicating an additional compositional effect. The evidence we have presented on spacing behavior does not negate the argument that parity-dependent stopping behavior was a powerful factor in the fertility transition. Our data also provide evidence of attempts to truncate childbearing. Specifically, the smaller the completed family size, the longer the ultimate birth interval; and ultimate birth intervals increase across cohorts controlling CEB and parity. But spacing appears to represent an additional strategy of fertility limitation. Thus, it may be necessary to distinguish spacing and stopping behavior if one wishes to clarify behavioral patterns within a population (Edlefsen, 1981; Friedlander et al., 1980; Rodriguez and Hobcraft, 1980). Because fertility transition theories imply increased attempts to limit family sizes, it is important to examine differential behavior within subgroups achieving different family sizes. It is this level of analysis which we have attempted to achieve in utilizing parity-specific birth intervals controlled by children ever born.(ABSTRACT TRUNCATED AT 400 WORDS)     

Does low fertility call for new policies in some Asian countries?

Over the past 2 decades, Japan, China, Singapore, Hong Kong, and South Korea have completed a demographic transition from high birth and death rates and runaway population growth to reduced fertility and mortality and population growth approaching replacement levels. Among the outcomes of fertility decline, 3 have particularly far reaching effects: 1) Changes in family types and structures. Marriage and family formation are postponed, childbearing is compressed into a narrow reproductive span that begins later and ends earlier, and higher-order births become rare. Large families are replaced by small ones, and joint and extended families tend to be replaced by nuclear families. 2) Shifts in the proportions of young and old. Declining fertility means that the population as a whole becomes older. Decreases in the proportion of children provides an opportunity to increase the coverage of education. Increases in the proportion of the elderly means higher medical costs and social and economic problems about care of the aged. 3) Changes in the work force. There is concern that low fertility and shortages of workers will cause investment labor-intensive industries to shift to countries with labor surpluses. Another outcome may be an increase in female participation in the work force. The potential consequences of rapid fertility decline have sparked debate among population experts and policy makers throughout Asia. Current family planning programs will emphasize: 1) offering a choice of methods to fit individual preferences; 2) strengthening programs for sexually active unmarried people; 3) encouraging child spacing and reproductive choice rather than simply limiting the number of births; 4) making information available on the side effects of various family planning methods; 5) providing special information and services to introduce new methods; and 6) promoting the maternal and child health benefits of breast feeding and birth spacing.     

Book reviews

Data from Hungary and Sweden are used to investigate the extent to which prematurity confounds the relationship between length of preceding birth interval and perinatal mortality. Controlling for length of gestation removes between 65 and 90 per cent of the excess mortality associated with birth intervals of less than 18 months; however, mortality among infants who are born less than 18 months after the birth of their previous sibling is still higher than among infants born after longer intervals. These results suggest that, although short birth intervals are associated with high perinatal mortality, estimates of the risks attributable to birth-spacing are overstated, if length of gestation is not taken into account.     

Some aspects of the relationship between the levels of infant mortality and fertility in the ESCAP region

The death of a child within the first year of life is a crucial factor in fertility decisions in a developing country. The infant mortality rate gives a close, inverse indication of the socioeconomic conditions of a country. This paper presents studies by Brass, Rutherford, Chowdhury, Khan and Chen, Agrawal, Iskander and Jones, in summary/abstract form. It concludes that the probabilities of survival are poorer for births of older women and/or higher parities. Early child deaths may increase the total period of exposure to the risk of conception. A lower infant and child mortality norm calls for fewer births to meet the needs for survivors. Child replacement motivational response seems to be strongest with the birth immediately following a death event. Agrawal analyzed the interval between successive births of 1107 women of Patna, Pakistan, according to the age of mother and sex and fate of the previous child. He observed that if a child died shortly after its birth, often a new pregnancy began within a short interval. The interval between 2 consecutive live births when the previous child was male and alive was greater than when the previous child was female and alive. The interval between 2 births was reduced if the child died in infancy and specially if this was a male child.     

Infant mortality,birth order,and sibship size: The role of heterogeneous risk and the previous‐death effect

This paper derives an analytic model to study biases in infant mortality estimates by birth order and sibship size, which occur when the death of an infant tends to shorten the next birth interval and mortality risk varies among families. We find that order‐specific and sibship‐size‐specific estimates are biased by a selection for high‐risk women across birth orders, since women with higher risk will tend to have shorter intervals, and more births, within a given period of time. Sibship‐size‐specific estimates are, in addition, biased by a selection of women who have experienced deaths, even if there is no heterogeneity in risk. Numerical examples based on data from Matlab, Bangladesh, are used to illustrate the possible magnitude of these biases. The results resemble patterns of infant mortality by birth order and sibship size which are often observed empirically.     

Estimating birth stopping and spacing behavior

A decomposition of age-specific marital fertility rates into indices related to spacing and stopping is developed by using Coale and Trussell's indices and the first few parity progression ratios. This approach leads to estimates of the mean birth interval among low-parity births that can be used to address the issue of fertility control early in marriage. In this way the model addresses several of the most serious limitations of Coale and Trussell's approach. The usefulness of the proposed indices is demonstrated by applications to historical data from the United States and Europe.     

To what extent does breastfeeding explain Birth-interval effects on early childhood mortality?

This article shows that in Nepal breastfeeding almost completely explains the effects of following birth interval on childhood mortality during the first 18 months of age and partially explains the effect of following birth interval on childhood mortality between 18 and 60 months of age. Breastfeeding does not explain the effect of preceding birth interval on childhood mortality. The analysis is based on application of hazard models to data from the 1976 Nepal Fertility Survey.     

The effects of pregnancy spacing on infant and child mortality in Matlab, Bangladesh: how they vary by the type of pregnancy outcome that began the interval

Using high-quality longitudinal data on 125,720 singleton live births in Matlab, Bangladesh, we assessed the effects of duration of intervals between pregnancy outcomes on infant and child mortality and how these effects vary over subperiods of infancy and childhood and by the type of outcome that began the interval. Controlling for other correlates of infant and child mortality, we find that shorter intervals are associated with higher mortality. Interval effects are greater if the interval began with a live birth than with another pregnancy outcome. In the first week of the child's life, the effects of short intervals are greater if the sibling born at the beginning of the interval died; after the first month, the effects are greater if that sibling was still alive. Many relationships found are consistent with the maternal depletion hypothesis, and some with sibling competition. Some appear to be due to correlated risks among births to the same mother.     

The momentum of mortality change

Mortality change is not usually assigned much importance as a source of population growth when future population trends are discussed. Yet it can make a significant contribution to population momentum. In populations that have experienced mortality change, cohort survivorship will continue varying for some time even if period mortality rates become constant. This continuing change in cohort survivorship can create a significant degree of mortality-induced population change, a process we call the 'momentum of mortality change'. The momentum of mortality change can be estimated by taking the ratio of e0 (the period life expectancy at birth) to CAL (the cross-sectional average length of life) for a given year. In industrialized nations, the momentum of mortality change can attenuate the negative effect on population growth of declining fertility or sustained below-replacement fertility. In India, where population momentum has a value of 1.436, the momentum of mortality change is the greatest contributor to its value.     

The impact of childhood mortality on Fertility in six rural Thanas of Bangladesh

In this article, we examine the relationship between child mortality and subsequent fertility using prospective longitudinal data on births and childhood deaths occurring to nearly 8000 Bangladeshi mothers observed over the 1982-1993 period, a time of rapid fertility decline. Generalized hazard-regression analyses are employed to assess the effect of infant and child mortality on the hazard of conception, with controls for birth order and maternal age and educational attainment. Results show that childhood mortality reduces the time to subsequent conception if the death occurs within a given interval, representing the combined effect of biological and volitional replacement. The time to conception is also reduced if a childhood death occurs during a prior birth interval, a finding that signifies an effect of volitional replacement of the child that died. Moreover, mortality effects in prior birth intervals are consistent with hypothesized insurance (or hoarding) effects. Interaction of replacement with elapsed time suggests that the volitional impact of child mortality increases as the demographic transition progresses. This volitional effect interacts with sex of index child. Investigation of higher-order interactions suggests that this gender-replacement effect has not changed over time.     

The origins of agriculture: Population growth during a period of declining health

The increase in the Neolithic human population following the development of agriculture has been assumed to result from improvements in health and nutrition. Recent research demonstrates that this assumption is incorrect. With the development of sedentism and the intensification of agriculture, there is an increase in infectious disease and nutritional deficiencies particularly affecting infants and children.Declining health probably increased mortality among infants, children and oldest adults. However, the productive and reproductive core would have been able to respond to this increase in mortality by reducing birth spacing. That is, agricultural populations increased in size, despite higher mortality, because intervals between births became shorter.     

Nepal survey shows that "family planning saves lives"

This article presents the results of the Nepal Family Health Survey (NFHS) conducted from January through June 1996. Data on fertility, family planning, and maternal and child health were collected from 8429 ever-married women aged 15-49 years. These women provided information on 29,156 children. Using the method of regression analysis, findings reveal those factors, such as young mothers, large families, and short birth intervals, substantially increase under-five mortality risks. However, socioeconomic factors have only a limited effect on under-five mortality. Statistics have suggested that much of the urban/rural differences in mortality have been due to factors closely related to residence, mother's level of education and economic status. In addition, although positive effects of interventions (antenatal and postpartum checkups, tetanus immunization and assistance at delivery by a traditional birth attendant) have been documented, statistical results show that few children in Nepal are receiving the benefits of maternal health care. In conclusion, results of the 1996 NFHS show that delaying, spacing, and limiting births can substantially reduce infant and child mortality.     

Which factors explain the decline in infant and child mortality in Matlab,Bangladesh?

Infant and child mortality rates have decreased substantially in Matlab, Bangladesh, as they have in many developing areas. We use data from the Matlab Demographic Surveillance System on nearly 94,000 singleton live births that occurred between 1987 and 2002 to investigate the extent to which the change in mortality over this period can be explained by changes in reproductive patterns and socio-economic characteristics. We estimate Cox proportional hazards models for four subperiods of infancy and childhood. Changes over time in reproductive patterns (maternal age, parity, and pregnancy spacing) and in the socio-economic characteristics we consider (e.g. maternal education, SES) explain between 10 and 40% of the decline in mortality rates. Changes in maternal education explain the largest portion of the reduction in infant and child mortality over time that we are able to explain, followed by reductions in the incidence of short interpregnancy intervals. In the other direction, decreases in fertility over time led to increases in the proportion of births that were first births, putting upward pressure on mortality.