Sex differentials in infant and child mortality in Korea

Abstract

This paper reports on a study of infant and child mortality in the Republic of Korea, a country known for a strong son preference, using the 1974 World Fertility Survey data. When the age‐specific probabilities of dying for ages zero to five are compared for male and female children, an unusual pattern of relatively high female mortality is observed. The higher female mortality is more pronounced during childhood than during infancy. Multivariate analysis of life tables, using a hazard model, shows that covariates influencing the mortality at young ages differ for male and female children and suggests that male and female children receive unequal care by their parents. The analysis also reveals different patterns of interaction between infant and child mortality and mother's fertility control behavior depending on the sex of the child.     

Relationships between pregnancy spacing,sex of infants,maternal age,and birth order,and neonatal and post‐neonatal mortality in Bangladesh

Abstract

The relationships between length of the interpregnancy interval, outcome of the pregnancy preceding the interval, sex of the infants, pregnancy order, maternal age, and maternal history of previous child deaths and neonatal and postneonatal mortality were explored in a rural Bangladeshi population using a multiple regression analysis. Specific interactions between the interpregnancy interval, outcome of the pregnancy preceding the interval, sex of the infants, and history of previous child deaths were examined. An inverse relationship was observed between postneonatal mortality and the length of the interpregnancy interval when the pregnancy preceding the interval was a surviving infant. No such trend was observed for neonatal mortality. Post‐neonatal mortality rates among children whose mothers had experienced two or more previous child deaths were essentially the same as that for infants whose mothers had experienced 0–1 child deaths when the interpregnancy intervals were more than 24 months. Although female infants have a lower neonatal mortality than male infants, the neonatal mortality rate for female infants conceived less than twelve months following a male infant birth was higher than for a male infant conceived less than twelve months following another male infant birth. Post‐neonatal mortality is consistently higher for female compared to male infants in all interval categories.     

A demographic analysis of skeletons from the Larson site (39WW2) Walworth County,South Dakota: Vital statistics

A life table methodology was used for paleodemographic analysis of skeletons from the Larson site (39WW2), an Arikara village and cemetery dated to circa A.D. 1750–1785. Vital statistics on mortality, survivorship, age-specific probability of death, life expectancy and crude mortality rate were derived from skeletal data. The population had an extremely high infant mortality rate and high rates of childhood mortality. The lowest probability of death was for adolescents. Mortality increased for young adults, ages 15–19. This increase was especially marked for females, the actual peak of adult female mortality was during ages 15–19. A second mode in the female mortality curve occurred at ages 35–39. The greatest percentage of male deaths was observed in the fourth decade, ages 30–34. Only 4.0% of the population attained the age of 50. The population crude death rate was 76 per thousand per year. This estimate, although high, is congruent with archaeological and historical sources which report a rapid Arikara population decline during the Post-Contact period. Causes of specific deaths appear to be linked to childbirth (affecting mother and infant), starvation, diseases especially tuberculosis, and intertribal warfare.     

Infant and child mortality in Pakistan--some trends and differentials

Data from reproductive histories collected in the Population, Labor Force and Migration Survey (PLM) of 1979 are used to analyze trends and differentials in infant and child mortality in Pakistan. Comparisons with the Pakistan Fertility Survey (PFS) findings are also presented. The main concern is to provide from the latest national data, the PLM, direct measures of infant and child mortality and to demonstrate the relatively static and low chances of survival for children in Pakistan. The apparent trends from the PLM and the PFS are similar and seem to confirm that infant and childhood mortality has ceased to decline, at least rapidly, since 1965-69. Neonatal mortality is higher at levels of 70-85 deaths/1000 compared to postneonatal mortality of 40-60 deaths/1000. Improvements in neonatal rates from 1950 until 1975 are only approximately 1/2 of those for postneonatal rates for that period. The relationship between maternal age and mortality in the PLM data confirms that children of youngest mothers experienced the highest rates of infant mortality; mortality is again higher for children of oldest mothers aged 35 and above. The pattern of mortality in the 2 surveys is similar except that in the PFS there was little variation among births higher than 5th order. Sex differentials in mortality are very clear in both surveys. Boys have higher chances of dying in the 1st month of life but then the probability of their surviving from age 1 to 5 years is higher, reflecting the behavioral preference for the male sex in this society. The data also demonstrate an almost monotonic decline in infant and child mortality associated with longer birth intervals. Childhood mortality shows a less clear association with preceding birth interval than does infant mortality. While neonatal mortality is much higher in rural than in urban areas, there are negligible differences in the postneonatal rate. The urban-rural differential continues into childhood, reflecting lower health care and nutrition of children in rural areas. The data confirm the importance of parental education, particularly that of mothers, as a contributor to the health and mortality of infants. Mortality between age 1 and 5 years for children of the rural educated group is lower than that for the urban uneducated indicating the strong influence that education of mothers can have in preventing child loss. The combined evidence from the PFS and PLM data stresses the importance of improving health facilities in the rural areas, in aneffort to reduce the differences in mortality by area of residence. The data from both surveys also suggest the need to restrict motherhood to between the ages of 20 and 34, when obstetrical and health risks are minimal, and indicate the definite advantages of increasing the spacing between children.     

Sibling mortality correlation in Kenya

This paper examines whether infant and child mortality risks among successive siblings are closely correlated, and if so, whether the survival status of the preceding child is an important factor affecting infant and child mortality in Kenya. The data were drawn from the 1988/89 Kenya Demographic and Health Survey. Logistic regression was used as the major method of data analysis. The results show that both infant and child mortality rates are significantly higher among subsequent children whose preceding siblings had died in infancy than for those whose preceding sibling had survived through infancy. The effect of the survival status of the preceding child on infant mortality was statistically strong, even after a large number of control variables were taken into account. However, its effect on child mortality appears to be spurious since it was rendered statistically insignificant when just a few control variables were introduced into the analysis. The results provide empirical evidence that infant and child mortality risks among successive siblings are closely correlated in Kenyan families, and that the effect of the survival status of the preceding child is important in determining infant mortality but not child mortality.     

Factors affecting infant and child mortality

This paper examines the determinants of infant and child mortality variations in Jordan, Yemen, Egypt, and Tunisia using data from WFS surveys. The analysis considers biological correlates of mortality--mother's age, birth order, birth interval, and previous infant loss--and several social factors--mother's and father's education, mother's residence, father's occupation, and mother's work experience since marriage. The estimates for the 4 countries show large variations in the mortality rates and an expected pattern of declining infant and child mortality during the period of 20 years prior to the survey. Further, the proportionate decline in child mortality in each country was generally greater than the proportionate decline in infant mortality. A persistent pattern of higher child mortality for females than for males is found, suggesting preferential care and treatment of male offspring. The higher mortality risk is found for infants born to very young and very old mothers, with short previous birth intervals, of higher birth orders, and where the previous infant had died. Among the socioeconomic characteristics, the education of the mother and rural-urban residence are found to affect infant survival. In childhood, among the demographic factors, only birth interval shows a significant effect on mortality. The risk of child mortality decreases considerably with the increase in the birth interval. The analysis of the effect of breastfeeding on mortality, although based on limited information, clearly shows the beneficial effect of breastfeeding on the infant's survival, especially during the early months of life. For all countries, the mortality rate for the non-breastfeeders is substantially higher than for the breastfeeders even when the effect of the other covariates is controlled.     

Effect of infant mortality on subsequent fertility in Pakistan and Sri Lanka

This study used data from the 1975 World Fertility Surveys in Pakistan and Sri Lanka to examine the association between fertility and infant mortality. A positive association between the mean number of children ever born and the number of child deaths was found in both rural and urban areas of each country. In Pakistan, women with no child loss had 3.3 children ever born while those who lost 1 child had 4.7 children; in Sri Lanka the figures were 3.5 and 5.4 children, respectively. However, child replacement was much less marked when controls were introduced for demographic and socioeconomic factors. When deaths at specific parities were examined, and age and time since previous birth were controlled, child replacement at the 1st parity was reduced to .3 in Pakistan and .2 in Sri Lanka. Further control for a series of socioeconomic factors (e.g. husband's level of education, husband's occupation, household structure, religion, standard of living) reduced the child replacement ratio to .2 children in Pakistan and zero in Sri Lanka. Replacement was slightly more pronounced when there were fewer surviving male children. This analysis suggests that the relationship between infant mortality and fertility is complex. A possibility that could not be explored in this study is that variation in fertilitty may itself be responsible for some of the variation in infant mortality.     

Infant and child mortality in Bangladesh

Socioeconomic differences and trends in infant and child mortality in Bangladesh are examined using data from the 1975 World Fertility Survey and 1979 Contraceptive Prevalence Survery. There is evidence of some recent decline in infant mortality and child mortality. Logit analysis of infant and child mortality indicates that sociodemographic variables such as mother's education, recent period, or higher birth orders, has significant independent effects upon the reduction of infant and child mortality. Other variables such as fetal loss, father's education, or land ownership had no consistent significant effect. On the other hand the effect of urban residence on infant and child mortality was positive after the control of sociodemographic variables. Mere concentration on the supply of modern medical services may bring limited returns unless they are reinforced by appropriate social changes, in particular those affecting the socioeconomic status of women. Educated mothers are likely to belong to higher income households, have better knowledge of how to care for children, and can bring more resources to the care of a sick child.     

Mortality estimates for South Kampala based on 1980 Uganda Population Census

In the absence of vital statistics data, analysis of the 1980 Uganda Population Census for South Kampala was able to provide estimates of infant, child, and adult mortality. Indirect techniques yielded estimated 1q0 values of 0.0860 for male infants, 0.0680 for female infants, and 0.0774 for infants of both sexes. The infant mortality rate estimated for 1980 is somewhat higher than that estimated for Kampala city in 1969 (0.0750), supporting medical professionals' opinion that infant mortality increased during the 1970s due to political and economic factors in Uganda and the consequent deterioration of health services. Child mortality (4q1), estimated in this study as 0.0491, appears to have declined during the 1970s; however, this unexpected finding may reflect differences in coverage and content errors in the 2 sets of data for 1969 and 1980. Adult mortality, based on the estimated survival rates from paternal and maternal orphanhood data and those from adjusted 12 values, is slightly lower than those for infant and child mortality. Expectation of life at birth estimates from various techniques show clearly that females have lower patterns of mortality than males. The estimated life expectation is 54.7 years for males, 59.3 years for females, and 57.0 years for both sexes. Overall, these estimates indicate a need for further reductions in mortality in Uganda as part of the overall development effort.     

Birth weight and other determinants of infant and child mortality in three provinces of China

Information on levels, trends and determinants of infant and child mortality was available from the 1985 In-depth Fertility Survey which was conducted in three provinces of China. Mortality of children below age 5 varied from 49 per 1000 live births in Shaanxi to 20 in Shanghai in 1980-85 and has declined substantially since 1960, from 206 in Shaanxi and 66 in Shanghai. Male mortality was considerably higher than female mortality in the neonatal and post-neonatal period, and at ages 1-5 years. Birth weight, place of residence and mother's education were found to be important determinants of mortality; age of mother and parity were less important.     

Factors influencing prereproductive mortality in the isolated and preindustrial western Mediterranean population of La Alpujarra, 1900-1950

We study the effects of several variables on the prereproductive mortality pattern in the isolated and rural population of La Alpujarra, located on the western Mediterranean coast (southeast Spain), in the first half of the 20th century. The study is a retrospective analysis from a total sample of 2,200 deliveries, 2,085 of which were born alive and 171 of which did not survive to the 20th birthday. The potential influences of birthdate of children, twinning, firstborn, parental inbreeding, and sex on Alpujarran mortality were analyzed through logistic regression. Parity, family size, and birth interval effects were estimated through the difference between observed and expected mortality rates. In every case four age groups of mortality were considered because of the large influence of child growth: neonatal (less than 1 month of life), postneonatal infant (between 1 month and 1 year old), childhood (1-5 years old), and youth (5-20 years old). The Alpujarran prereproductive mortality pattern can be summarized as the result of three main risk factors: biodemographic, biomechanical, and social and health determinants. In general, every factor showed a decreased effect as children grew. The most significant determinants were birthdate of children, which is more related to increased mother's awareness of child care than to health improvement, and family size associated with decreasing alimentary resources as the sibling number increased. Male mortality was higher than female mortality in children older than 1 year but not for infant mortality, possibly as a result of a reproductive behavior favorable to males. Although firstborn status and twinning appeared associated with high mortality, maternal age and birth interval were related to low risk, but these influences always ceased after the first month of life. Parental inbreeding did not show any effect on infant, childhood, or youth mortality.     

Multivariate analysis of infant and child mortality in Java and Bali

The data used in this analysis come from the 1976 Indonesian Fertility Survey, part of the World Fertility Survey. The data are examined 3 times, fitting them to models which include different combinations of independent variables. The dependent variables are: 1) the proportion of children born between 5 and 15 years before the survey who died before their 1st birthday, for infant mortality; and 2) among those alive on their 1st birthday, the proportions who died before reaching their 5th birthday, for child mortality. The figures indicate that the chance of dying for children who were 1st born, born shortly after a previous child, whose previous sibling had died, who lived in rural areas, or had parents who were young and with little education, was greater than for children without these characteristics. In all 3 models used, the greatest net effects are attributed to the survival of a preceding sibling or the length of the preceding interval. Birth order does not have a significant gross effect on infant mortality, but the net effects are significant because of the control on maternal age. Education of both parents has significant effects, but these are overshadowed in magnitude by the demographic variables. Maternal education has a greater influence in determining differences in child mortality than was found for infant mortality. Father's education also has a significant independent effect, but mainly for 1st births. It is uncertain whether these variables are measuring the effect of schooling as such, or other characteristics such as economic status or various social roles adopted by people with different levels of education. The variables distinguishing urban from rural status shows significant gross effects which are greatly reduced when controls for other variables are introduced in the model which includes all births. That is to say, the difference in the survival chances of a child in the city is more a function of the education of its parents, and the associated demographic variables than city residence as such. Access to medical services is quite probably the main element in these differences. The findings are weakened to some extent by the lack of satisfactory data on household economic status which might have provided a better base for indirectly discerning the effects of nutrition and sanitation on mortality at young ages.     

Effect of birth spacing on infant and child mortality in rural Nepal

This examination of the effect of birth spacing on infant and child mortality in rural Nepal is based on data from the Nepal Fertility Survey 1976 carried out by the Nepal Family Planning and Maternal Child Health Project in collaboration with the World Fertility Survey. The study confirms that the higher risk of infant death to 1st born children is mainly due to the higher proportion of younger women having 1st births, rather than due to their being 1st order births per se. The effect of maternal age on infant and child mortality is largely associated with birth interval. Previous birth interval, therefore, stands out as the most important factor affecting infant mortality; the next most important factor is the survival of the preceding child. A child born after an interval of less than 18 months since the previous live birth has a 31% higher risk of dying during infancy than 1 born after an interval of 1 1/2 to 2 years. The risk of the index child's dying is only 50% of that when its preceding sibling is dead. Neither education of mother nor education of father has a significant effect on infant mortality in rural Nepal.     

Infant and child mortality in India in the last two decades: a geospatial analysis

BACKGROUND: Studies examining the intricate interplay between poverty, female literacy, child malnutrition, and child mortality are rare in demographic literature. Given the recent focus on Millennium Development Goals 4 (child survival) and 5 (maternal health), we explored whether the geographic regions that were underprivileged in terms of wealth, female literacy, child nutrition, or safe delivery were also grappling with the elevated risk of child mortality; whether there were any spatial outliers; whether these relationships have undergone any significant change over historical time periods. METHODOLOGY: The present paper attempted to investigate these critical questions using data from household surveys like NFHS 1992-1993, NFHS 1998-1999 and DLHS 2002-2004. For the first time, we employed geo-spatial techniques like Moran's-I, univariate LISA, bivariate LISA, spatial error regression, and spatiotemporal regression to address the research problem. For carrying out the geospatial analysis, we classified India into 76 natural regions based on the agro-climatic scheme proposed by Bhat and Zavier (1999) following the Census of India Study and all estimates were generated for each of the geographic regions. RESULT/CONCLUSIONS: This study brings out the stark intra-state and inter-regional disparities in infant and under-five mortality in India over the past two decades. It further reveals, for the first time, that geographic regions that were underprivileged in child nutrition or wealth or female literacy were also likely to be disadvantaged in terms of infant and child survival irrespective of the state to which they belong. While the role of economic status in explaining child malnutrition and child survival has weakened, the effect of mother's education has actually become stronger over time.     

Birth interval, mortality and growth of children in a rural area in Kenya

The impact of the length of birth intervals on mortality and growth of children from the perinatal period to 2 years in the Northern Division of Machakos District, Eastern Province, Kenya, were analyzed. There are 2 types of birth intervals: 1) the prospective birth interval--between the birth concerned (the 1st birth of the interval pair) and the subsequent birth; and 2) the retrospective birth interval--between the birth considered (the 2nd of the interval pair) and the preceeding birth. This study includes 3019 women who had at least 1 live birth between April, 1974 and April, 1981. They gave birth to 6778 children (including stillbirths). Births occurring in 1974 are excluded in the analysis because of considerable underregistration. 102 stillbirths and 213 deaths in the 1st 2 years are analyzed. They have been grouped into deaths during the perimatal period; the 1st year after the 1st week of life (infant period); and the 2nd year of life. The most convient method of analysis of the relation between retrospective birth interval and mortality is multivariate analysis, as the intermedicate biological and behavioral factors through which birth intervals can affect health are simultaneously influenced by other variables like maternal age and birth order; the log linear model is applied here. The probability of dying is the dependent variable. The impact of short prospective intervals are closely associated. Only infant and child deaths occurring after the conception of the next child are included. The size of cohorts in which these deaths occur can be calculated with a life table approach. The mortality probability between 5 and 12 months for children with short prospective intervals is .034. This is higher than the corresponding rate for all children in the area (P0.05). It is shown that children with short retrospective or prospective birth intervals do not run a greater risk of mortality or growth retardation than children with longer intervals, neither during the perinatal period nor during the 1st 2 years of life.     

The effects of lactation and infant care on adult energy budgets in wild siamangs (Symphalangus syndactylus)

In mammals with biparental care of offspring, males and females may bear substantial energetic costs of reproduction. Adult strategies to reduce energetic stress include changes in activity patterns, reduced basal metabolic rates, and storage of energy prior to a reproductive attempt. I quantified patterns of behavior in five groups of wild siamangs (Symphalangus syndactylus) to detect periods of high energetic investment by adults and to examine the relationships between infant care and adult activity patterns. For females, the estimated costs of lactation peaked at around infant age 4–6 months and were low by infant age 1 year, whereas the estimated costs of infant‐carrying peaked between ages 7 and 12 months, and approached zero by age 16 months. There was a transition from primarily female to male care in the second year of life in some groups. Females spent significantly less time feeding during lactation than during the later stages of infant care, suggesting that female siamangs do not use increased food intake to offset the costs of lactation. Female feeding time was highest between infant ages 16 and 21 months, a period of relatively low female investment in the current offspring that coincided with the period of highest male investment in infant care. This suggests that male care may reduce the costs of infant care for females in the later stages of a reproductive attempt. The female energy gain resulting from male care was likely invested in somatic maintenance and future reproduction, rather than the current offspring. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

The delineation of fertility strategies in a tribal population of India: the Koyas of Koraput District,Orissa

Demographic data collected for a tribal population of India, the Koyas of Koraput District, Orissa, were examined in light of 2 models of reproductive behavior associated with the economic value of children: the replacement effect and son survivorship motivation. Both models are united in the concept that infant/child mortality affects subsequent fertility. The database consists of retrospective fertility histories of Koya women who had completed their reproductive period. The total number was 260, with the total offspring numbering 1407. 2 distinct cohorts of women were formed for the purpose of analysis, separated only by the criterion of offspring survival: women who had experienced infant child mortality (129 women with 739 children); and women who completed their reproductive period without suffering offspring loss of this nature (132 women with 668 children). The cohort without child loss had a mean parity of 5.10, lower than the average parity of 5.73 recorded for the cohort whose reproductive histories included at least 1 infant/child death. Age specific marital fertility and birth interval analyses indicated that this differential was because of biological, not behavioral, factors. The age pattern of fertility of females suffering offspring mortality failed to demonstrate a high rate of childbearing in the later age intervals of the reproductive period, a characteristic pattern of couples attempting to "replace" lost offspring. Birth interval analysis pointed to biological "interval effect," whereby infant/child mortality caused a cessation of lactation and hence a shortening of postpartum amenorrhea. Computer simulation further indicated that the higher fertility differential of the cohort experiencing offspring loss still did not result in high son survivorship values. The findings agree with earlier studies indicating that for predemographic transitional populations, economically motivated fertility strategies are ineffectual.     

Demographic study of a large-sized unit-group of chimpanzees in the mahale mountains,Tanzania: A preliminary report

Long-term demographic observations on a large-sized unit-group of chimpanzees in the Mahale Mountains, Tanzania, are summarized. The unit-group, the M group, contains over 100 individuals, which makes it the largest unit-group ever reported. The age-sex composition, natality, mortality and transfers of the M group are analyzed. An attempt is made to illustrate an age-sex pyramid of the group by estimating the ages of all the individuals in the group. The results reveal that: (1) the mortality rate of the male infants within 1 year almost doubled that of female infant; (2) adult male to adult female ratio of the M group is considerably higher than any other unit-groups elsewhere; and (3) the M group contains a relatively large number of old animals over 40 years of age, suggesting that the longevity of wild chimpanzees might be greater than estimated so far.     

Infant mortality and child health in Brazil

Child health is a central issue in the public policy agenda of developing countries. Several policies aimed at improving child health have been implemented over the years, with varying degrees of success. In Brazil, such policies have triggered a significant decline in infant mortality rates over the last 30 years. Despite this improvement, however, mortality rates are still high compared to international standards. Moreover, there is considerable imbalance across Brazilian municipalities suggesting that various policies should be adopted. We investigate the determinants of infant mortality at the municipal level and provide an analysis of the factors affecting child health at the individual level. To analyze the mortality rate, we estimate static and dynamic panel data models using four censuses covering the period from 1970 to 2000. The demand for child health, on the other hand, is addressed through a household decision model, estimated using anthropometric data from the 1996 Standard of Living Survey. The results obtained indicate that a rise in sanitation, education and per capita income contributed to the decline of infant mortality in Brazil, with stronger impacts in the long run than in the short run. The fixed effects associated with county characteristics explain the observed dispersion in child mortality rates. The results from the decision model are confirmed by the findings of the mortality model: education, sanitation and poverty are the most important causes of poor child health in Brazil.     

Kin and Child Survival in Rural Malawi

This paper investigates the impact of kin on child survival in a matrilineal society in Malawi. Women usually live in close proximity to their matrilineal kin in this agricultural community, allowing opportunities for helping behavior between matrilineal relatives. However, there is little evidence that matrilineal kin are beneficial to children. On the contrary, child mortality rates appear to be higher in the presence of maternal grandmothers and maternal aunts. These effects are modified by the sex of child and resource ownership: female children and children in households where women, rather than men, own land suffer higher mortality rates in the presence of maternal kin. These modifiers suggest the detrimental effects of matrilineal kin may result from competition between such kin for resources. There are some positive effects of kin on child survival: the presence of elder siblings of both sexes is correlated with higher survival rates, and there is some weak evidence that paternal grandmothers may be beneficial to a child’s survival chances. There is little evidence that any male kin, whether matrilineal or patrilineal, and including fathers, affect child mortality rates. This study highlights the importance of taking social and ecological context into account when investigating relationships between kin.