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.     

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.     

Changing determinants of infant and child mortality: on the basis of the Korean experience, 1955-73

Data from the 1974 Korean National Fertility Survey were analyzed to learn more about the main determinants of infant and child mortality in the course of mortality decline and how they change. In the Korean survey, about 5000 eligible women were selected for the individual survey and the sample design aimed at a self-weighting nationally representative and probability sample. Preliminary analysis showed clear mortality differentials between different socioeconomic levels and between demographic subgroups in infant and child mortality during the period 1955-73 in Korea. To examine the net effect of each variable on mortality, the logit-linear model was used. A table shows the probability level of 4 variables -- maternal age, birth order, mother's education, and number of rooms used by household -- in Korea, when the effects of others were controlled. In the urban areas, only the socioeconomic factors were the main determinants of infant mortality on all the birth cohorts. Mother's education and number of rooms used strongly affected infant mortality in the 1955-59 and 1960-64 birth cohorts, but the effects became weaker in the 1965-69 and 1970-73 birth cohorts, and their statistical significance was reduced. In the rural areas, the effects of 3 variables -- the exception being number of rooms used -- on infant mortality were statistically significant. It is concluded that the main determinants of infant mortality in urban areas were socioeconomic factors. The main determinants of infant mortality in the rural areas were demographic in the earlier birth cohorts, but in the recent birth cohorts mother's education, a socioeconomic factor, became the main determinant while the effects of demographic variables became weaker and finally disappeared. The change in the determinants of child mortality appears to be the reverse of that for infant mortality. Prior to the introduction of the national development program, in the rural areas mother's education was the main determinant of child mortality (rural 1955-59 cohort), but with the socioeconomic development the determinants changed to give dominance to demographic factors (urban 1955-59) cohort and, in the recent period, even the effects of demographic factors on child mortality became weaker (urban 1960-69 cohort). When the differences in living status by maternal age were weaker and the competition among siblings less because of small family size, only the socioeconomic variables remained as main determinants affecting child mortality.     

Birth order and health status in a British national sample.

Researchers analyzed data from the National Child Development Study--a cohort of every child born in England, Scotland, and Wales during the 1st week of March 1953 with follow up studies in 1965, 1969, 1973, and 1980-1981 to examine the relationship between health status and birth order and whether children with low birth orders were less likely to experience illness than those with older siblings. 1st born children tended to have received the needed number of immunizations, but children of higher birth order did not tend to have received them. Further they were more likely to have attended infant welfare and toddler clinics for health care than children of higher birth order. The only childhood contagious disease which demonstrated a social class effect was pertussis. It tended to afflict children from nonmanual homes regardless of birth order. Absences from school lasting between 1 week-1 month of 1st born children were less frequent than for other children. The leading reasons for 1st, 3rd, and later born 11 year old children who experienced such long absences included infectious diseases; bronchitis; ear, nose, and throat complaints; pneumonia; tonsillitis, or viral influenza. After age 15, 1st and 2nd born children were less likely to be absent and, if absent, they tended to only miss 1 week of school. Significantly more 3rd and 4th born children were absent from school for 1 week-3 months. 1st and 2nd born children from more affluent families tended to have early childhood asthma. In conclusion, the health experiences of the later birth orders were different than those of the 1st born. This did not mean, however, that later birth order children were in poorer health than 1st born children.     

Determinants of infant and child mortality in the West Bank and Gaza Strip

Infant and child mortality in the West Bank and Gaza Strip has steadily reduced since 1967, even though fertility has remained extremely high. In this paper the determinants of infant and child mortality are discussed, with particular emphasis on the role of consanguineous marriages, short birth spacing and maternal education. It is shown that short birth spacings and type of marriage are more important determinants of infant mortality than maternal education. Moreover, the relative role of consanguineous marriages appears to increase with time.     

Maternal, neonatal and community factors influencing neonatal mortality in Brazil

Child mortality (the mortality of children less than five years old) declined considerably in the developing world in the 1990s, but infant mortality declined less. The reductions in neonatal mortality were not impressive and, as a consequence, there is an increasing percentage of infant deaths in the neonatal period. Any further reduction in child mortality, therefore, requires an understanding of the determinants of neonatal mortality. 209,628 birth and 2581 neonatal death records for the 1998 birth cohort from the city of S?o Paulo, Brazil, were probabilistically matched. Data were from SINASC and SIM, Information Systems on Live Births and Deaths of Brazil. Logistic regression was used to find the association between neonatal mortality and the following risk factors: birth weight, gestational age, Apgar scores at 1 and 5 minutes, delivery mode, plurality, sex, maternal education, maternal age, number of prior losses, prenatal care, race, parity and community development. Infants of older mothers were less likely to die in the neonatal period. Caesarean delivery was not found to be associated with neonatal mortality. Low birth weight, pre-term birth and low Apgar scores were associated with neonatal death. Having a mother who lives in the highest developed community decreased the odds of neonatal death, suggesting that factors not measured in this study are behind such association. This result may also indicate that other factors over and above biological and more proximate factors could affect neonatal death.     

Reproductive parameters of female Japanese macaques: Thirty years data from the arashiyama troops,Japan

Over a 30-year period from 1954 to 1983, 975 live births were recorded for Japanese macaque females at the Iwatayama Monkey Park, Arashiyama, Japan. Excluding unknown birth dates, primiparous mothers gave birth to 185 infants (182 cases with age of mother known) and multiparous mothers gave birth to 723 infants (603 cases with age of mother known). The peak month of birth was May with 52.3% of the total births occurring during the period. Multiparous females who had not given birth the previous year did so earlier than multiparous females who had given birth the previous year and also earlier than primiparous females. Among the females who had given birth the previous year, females whose infant had died gave birth earlier than females who had reared an infant the previous year. The offspring sex ratio (1:0.97) was not significantly different from 1:1, and revealed no consistent association with mother's age. Age-fecundity exhibited a humped curve. The annual birth rate was low at the age of 4 years but increased thereafter, ranging between 46.7% and 69.0%, at between 5 and 19 years of age, but again decreased for females between 20 and 25 years of age. Some old females displayed clear reproductive senescence. The infant mortality within the first year of age was quite low (10.3%) and the neonatal (less than 1 month old) mortality rate accounted for 49.0% of all infant deaths. There was no significant difference between the mortality rates of male and female infants. A female's rank-class had no apparent effect on the annual birth rate, infant mortality, and offspring sex ratio. These long-term data are compared with those from other primate populations.     

Using birth defects registry data to evaluate infant and childhood mortality associated with birth defects: an alternative to traditional mortality assessment using underlying cause of death statistics

BACKGROUND: Although birth defects are a leading cause of death in infancy and early childhood, the proportion of all deaths to children with clinically diagnosed birth defects is not well documented. The study is intended to measure the proportion of all deaths to infants and children under age 10 occurring to children with birth defects and how and why this proportion differs from the proportion of deaths due to an underlying cause of congenital anomalies using standard mortality statistics. METHODS: A linked file of Michigan livebirths and deaths was combined with data from a comprehensive multisource birth defects registry of Michigan livebirths born during the years 1992 through 2000. The data were analyzed to determine the mortality rate for infants and children with birth defects and for children with no reported birth defect. Mortality risk ratios were calculated. The underlying causes of death for children with birth defects were also categorized and compared to cause- specific mortality rates for the general population. RESULTS: Congenital anomalies were the underlying cause of death for 17.8% of all infant deaths while infants with birth defects were 33.7% of all infant deaths in the study. Almost half of all Michigan deaths to children aged 1 to 2 were within the birth defects registry, though only 15.0% had an underlying cause of death of a congenital anomaly based upon standard mortality statistics. The mortality experience among children with birth defects was significantly higher than other children throughout the first 9 years of life, ranging from 4.6 for 5 year olds to 12.8 for children 1 to 2. Mortality risk ratios examined by cause of death for infants with birth defects were highest for other endocrine (28.1), other CNS (28.1), and heart (21.9) conditions. For children 1 through 9, the highest differential risk was seen for other perinatal conditions (39.0), other endocrine (29.7), other CNS (24.5), and heart (21.4). CONCLUSIONS: Childhood mortality analyses that incorporate birth defects registry data provide a more comprehensive picture of the full burden of birth defects on mortality in infant and children and can provide an effective mechanism for monitoring the survival and mortality risks of children with selected birth defects on a population basis.     

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.     

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.     

Rural-urban migration and child survival in urban Bangladesh: are the urban migrants and poor disadvantaged?

This paper analyses the levels and trends of childhood mortality in urban Bangladesh, and examines whether children's survival chances are poorer among the urban migrants and urban poor. It also examines the determinants of child survival in urban Bangladesh. Data come from the 1999-2000 Bangladesh Demographic and Health Survey. The results indicate that, although the indices of infant and child mortality are consistently better in urban areas, the urban-rural differentials in childhood mortality have diminished in recent years. The study identifies two distinct child morality regimes in urban Bangladesh: one for urban natives and one for rural-urban migrants. Under-five mortality is higher among children born to urban migrants compared with children born to life-long urban natives (102 and 62 per 1000 live births, respectively). The migrant-native mortality differentials more-or-less correspond with the differences in socioeconomic status. Like childhood mortality rates, rural-urban migrants seem to be moderately disadvantaged by economic status compared with their urban native counterparts. Within the urban areas, the child survival status is even worse among the migrant poor than among the average urban poor, especially recent migrants. This poor-non-poor differential in childhood mortality is higher in urban areas than in rural areas. The study findings indicate that rapid growth of the urban population in recent years due to rural-to-urban migration, coupled with higher risk of mortality among migrant's children, may be considered as one of the major explanations for slower decline in under-five mortality in urban Bangladesh, thus diminishing urban-rural differentials in childhood mortality in Bangladesh. The study demonstrates that housing conditions and access to safe drinking water and hygienic toilet facilities are the most critical determinants of child survival in urban areas, even after controlling for migration status. The findings of the study may have important policy implications for urban planning, highlighting the need to target migrant groups and the urban poor within urban areas in the provision of health care services.     

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.     

Socioeconomic, demographic and environmental determinants of infant mortality in Nepal

The Nepal Fertility and Family Planning Survey of 1986 demonstrated that demographic variables, previous birth interval and survival of preceding child, still predominated as determinants of infant mortality, particularly in rural areas of Nepal. However, in urban Nepal, where the level of socioeconomic development is higher, an environmental variable, along with previous birth interval and survival of preceding child emerges as important in determining infant mortality. Separate policy measures for child survival prospects in rural and urban Nepal are suggested.     

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.     

Analyzing infant mortality with geoadditive categorical regression models: a case study for Nigeria

In this paper, we analyze infant mortality in Nigeria based on the data set from the 1999 Nigeria Demographic and Health Survey (NDHS). We investigate spatial patterns at a highly disaggregated level of Nigerian states and consider non-linear effects of mother's age at birth. Time to the occurrence of a child's death can intuitively be considered to be categorical in nature and the determinants of a child's death may differ in different age groups. Thus, it may be desirable to investigate separately the death of a child in the first month and in the remaining 11 months of the first year of life. To avoid selection bias, the data set used for this case study is based on information on children who were born 12 months preceding the survey. Inference is Bayesian and is based on Markov chain Monte Carlo (MCMC) techniques. We find that spatial variation and the determinants of death indeed differ considerably for the two age groups considered.     

Kin and birth order effects on male child mortality: three East Asian populations, 1716–1945

Human child survival depends on adult investment, typically from parents. However, in spite of recent research advances on kin influence and birth order effects on human infant and child mortality, studies that directly examine the interaction of kin context and birth order on sibling differences in child mortality are still rare. Our study supplements this literature with new findings from large-scale individual-level panel data for three East Asian historical populations from northeast China (1789–1909), northeast Japan (1716–1870), and north Taiwan (1906–1945), where preference for sons and first-borns is common. We examine and compare male child mortality risks by presence/absence of co-resident parents, grandparents, and other kin, as well as their interaction effects with birth order. We apply discrete-time event-history analysis on over 172,000 observations of 69,125 boys aged 1–9 years old. We find that in all three populations, while the presence of parents is important for child survival, it is more beneficial to first/early-borns than to later-borns. Effects of other co-resident kin are however null or inconsistent between populations. Our findings underscore the importance of birth order in understanding how differential parental investment may produce child survival differentials between siblings.     

Sex differentials in infant and child mortality in Korea

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 0 to 5 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.     

Housing quality and child mortality in the rural Philippines

Factors influencing child survival to age 5 are investigated for a rural sample in lloilo Province, Philippines. Considered are construction materials in walls, doors, windows, and floors and the typpes of toilet facilities. 707 women were asked how many children they had borne alive; the sexes and dates of each live birth; whether each child was still living; and if not at what age the child had died. This study focused retrospectively on mortality among 2359 children born between 1960 and 1973. About 4.9% had died before age 5. This is 1/2 of what was observed nationally for rural children in the 1978 fertility survey. Health conditions in rural Iloilo Province may have been more favorable than in other rural parts of the nation. Income generated from shipping, lumbering, and fish culture may have also contributed to the lower rate of child mortality observed in this sample. The sex ratio of the children was 102, well within the range regarded as typical. A logit regression was employed. Of the 207 girls with low demographic risk and worse quality housing, 249 were estimated to survive to age 5 and 18 to die before age 5. Sex was not an important factor in child mortality. Boys and girls had about equal chances of surviving. A social-demographic risk factor commonly linked with infant mortality is breast feeding. Breastfed infants from a number of developing countries have had lower rates of infant mortality. A slightly larger % of nonbreastfed children (96.9%) survived to age 5 than did breastfed children. Living in a poorly constructed dwelling reduced the odds of a child's survival. Estimates from the Brass method showed that the expected probability of children dying before age 5 was .073 and .035, representing life expectancies at birth of 63.4 and 69.9 years.     

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.     

Maternal and paternal age at delivery, birth order, and risk of childhood onset type 1 diabetes: population based cohort study

ObjectiveTo estimate the associations of maternal and paternal age at delivery and of birth order with the risk of childhood onset type 1 diabetes.DesignCohort study by record linkage of the medical birth registry and the national childhood diabetes registry in Norway.SettingNorway.SubjectsAll live births in Norway between 1974 and 1998 (1.4 million people) were followed for a maximum of 15 years, contributing 8.2 million person years of observation during 1989-98. 1824 cases of type 1 diabetes diagnosed between 1989 and 1998 were identified.ResultsThere was no association between maternal age at delivery and type 1 diabetes among firstborn children, but among fourthborn children there was a 43.2% increase in incidence of diabetes for each five year increase in maternal age (95% confidence interval 6.4% to 92.6%). Each increase in birth order was associated with a 17.9% reduction in incidence (3.2% to 30.4%) when maternal age was 20-24 years, but the association was weaker when maternal age was 30 years or more. Paternal age was not associated with type 1 diabetes after maternal age was adjusted for.ConclusionsIntrauterine factors and early life environment may influence the risk of type 1 diabetes. The relation of maternal age and birth order to risk of type 1 diabetes is complex.

What is already known on this topic

Maternal age at birth is positively associated with risk of childhood onset type 1 diabetesStudies of the effect of birth order on risk of type 1 diabetes have given inconsistent results

What does this study add?

In a national cohort, risk of diabetes in firstborn children was not associated with maternal ageIncreasing maternal age was a risk factor in children born second or laterThe strength of the association increased with increasing birth order