Neonatal mortality in the empowered action group states of India: trends and determinants

In India, the eight socioeconomically backward states of Bihar, Chhattisgarh, Jharkhand, Madhya Pradesh, Orissa, Rajasthan, Uttaranchal and Uttar Pradesh, referred to as the Empowered Action Group (EAG) states, lag behind in the demographic transition and have the highest infant mortality rates in the country. Neonatal mortality constitutes about 60% of the total infant mortality in India and is highest in the EAG states. This study assesses the levels and trends in neonatal mortality in the EAG states and examines the impact of bio-demographic compared with health care determinants on neonatal mortality. Data from India's Sample Registration System (SRS) and National Family and Health Survey (NFHS-2, 1998-99) are used. Cox proportional hazard models are applied to estimate adjusted neonatal mortality rates by health care, bio-demographic and socioeconomic determinants. Variations in neonatal mortality by these determinants suggest that universal coverage of all pregnant women with full antenatal care, providing assistance at delivery and postnatal care including emergency care are critical inputs for achieving a reduction in neonatal mortality. Health interventions are also required that focus on curtailing the high risk of neonatal deaths arising from the mothers' younger age at childbirth, low birth weight of children and higher order births with short birth intervals.     

Socioeconomic status and infant mortality among Hispanics in a southwestern city

Recent investigations of infant mortality in the Southwest part of the US have shown that Spanish surname infant death rates are lower than might be expected from the relatively low socioeconomic standing of the Spanish surname population, a phenomenon that appears to be confined to the neonatal componont of the infant mortality rate. The relationship between socioeconomic status (ses) and infant mortality is examined overall and separately within the Anglo and Spanish surname populations of Corpus Christ, Texas. The investigation utilizes data from the 36 Nueces County census tracts. Most recent data on infant, neonatal, and postneonatal mortality was provided by the local health department. Subjects were limited to Anglos and those whites with at least 1 Spanish surname parent. The 1979-1983 cohort is analyzed. Information from the 1980 US census was utilized to divide the 36 census tracts into 3 SES groups: high, medium and low. The most immediately striking aspect of the findings is the significant inverse gradient in Anglos between SES and both the total infant mortality rate (IMR) and the neonatal mortality (NMR), a gradient which is nonexistent in the Spanish surname population as well as overall. In addition, Anglos and Spanish persons differ significantly with respect to all IMRs and NMRs. In the high and medium SES groups and overall, all Anglo rates are lower, while in the low SES group, Spanish surname rates are lower. These findings suggest that, among Anglos, SES is a crucial factor in infant deaths, whereas, among the Spanish surname population, having a medium or high SES does not offer any additional protection against mortality. Alternatively, lower SES does not translate into significantly lower infant mortality among Spanish persons. These findings provide support for the study's hypotheses that the SES-infant mortality association is weaker among Spanish persons than among Anglos. The analysis also shows the importance of analyzing the SES-infant mortality association separately by ethnicity. Studies in larger cities and also studies utilizing matched birth and death records are needed to further elaborate these findings.     

Birth-weight-specific infant and neonatal mortality: effects of heterogeneity in the birth cohort

Birth-weight-specific infant mortality is examined using a novel statistical procedure, parametric mixtures of logistic regressions. The results indicate that birth cohorts are composed of two or more subpopulations that are heterogeneous with respect to infant mortality. One subpopulation appears to account for the "normal" process of fetal development, while the other, which accounts for the majority of births at both low and high birth weights, may represent fetuses that were "disturbed" during development. Surprisingly, estimates of neonatal and infant mortality indicate that the "disturbed" subpopulation has lower birth-weight-specific mortality, although overall crude mortality rates are higher for this subpopulation. It is hypothesized that this is due to high rates of fetal loss among the "disturbed" subpopulation, resulting in a highly selected group at birth. The heterogeneity identified in the birth cohort could be responsible for recent decelerations in the decline in infant mortality, and might be the cause of unexplained ethnic differences in birth-weight-specific infant mortality. The novel statistical methodology developed here has broad application within human biology. In particular, it could be used in any context where parametric mixture modeling is applied, such as complex segregation analysis.     

The Apgar Score and Infant Mortality

Objective

To evaluate if the Apgar score remains pertinent in contemporary practice after more than 50 years of wide use, and to assess the value of the Apgar score in predicting infant survival, expanding from the neonatal to the post-neonatal period.

Methods

The U.S. linked live birth and infant death dataset was used, which included 25,168,052 singleton births and 768,305 twin births. The outcome of interest was infant death within 1 year after birth. Cox proportional hazard-model was used to estimate risk ratio of infant mortality with different Apgar scores.

Results

Among births with a very low Apgar score at five minutes (1–3), the neonatal and post-neonatal mortality rates remained high until term (≥ 37 weeks). On the other hand, among births with a high Apgar score (≥7), neonatal and post-neonatal mortality rate decreased progressively with gestational age. Non-Hispanic White had a consistently higher neonatal mortality than non-Hispanic Black in both preterm and term births. However, for post-neonatal mortality, Black had significantly higher rate than White. The pattern of changes in neonatal and post-neonatal mortality by Apgar score in twin births is essentially the same as that in singleton births.

Conclusions

The Apgar score system has continuing value for predicting neonatal and post-neonatal adverse outcomes in term as well as preterm infants, and is applicable to twins and in various race/ethnic groups.     

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.     

Sex differences in infant mortality in Spitalfields, London, 1750-1839

This study examines sex differences in infant mortality in Spitalfields, London, and the estimated contribution of endogenous and exogenous factors to neonatal and infant mortality using the biometric model from 1750 to 1839. There was a marked decline in the risk of death during infancy and the neonatal period for both sexes during the study period. There was significant excess male infant mortality compared with that of females in the 1750-59 cohort, estimated from baptism and burial registers, but not in later cohorts. Similarly, males had higher neonatal mortality rates than females in 1750-59 but not in later cohorts. Biometric analyses suggest that the observed decrease in neonatal mortality in both sexes was caused by a reduction in both endogenous and exogenous causes of death. The contribution of maternal health and breast-feeding practices to the observed patterns of mortality is discussed in the light of available evidence.     

The relationship between socioeconomic status and infant mortality in metropolitan Ohio, 1999-2001

Empirical evidence has consistently documented the direct relationship between infant mortality and socioeconomic inequality in the United States and numerous other countries. While the majority of these studies reveal an inverse relationship between socioeconomic level and infant mortality, not even this finding is free from disagreement. Furthermore, the specific nature and magnitude of this relationship has varied over time. This study will examine the relationship between socioeconomic status and infant mortality in metropolitan Ohio by using birth and infant death data centered on the 2000 Census. The analyses presented herein will describe and analyze the relationship between infant mortality and socioeconomic status in metropolitan Ohio in the year 2000. The key finding is that in spite of remarkable declines in infant mortality during the past several decades, most notably in neonatal mortality, there continues to be a pronounced inverse association between the infant death rate and the economic status of a population.     

Deformed nasal septa and relaxed selection

Abstract

Demographic studies undertaken in several Andean countries have found that women residing at high altitudes have significantly fewer live births than do their low altitude counterparts. This reduction has been explained as being due to various factors: the debilitating effects of hypoxia upon the reproductive system; the effects of sociocultural factors which vary with altitude and which affect reproductive behavior; and errors in data collection. In order to examine the validity of some of these hypotheses, the fertility of a group of 906 Bolivian women residing at low, medium, and high altitudes was examined. The women were selected from the lower socioeconomic strata and reported never having used any method of contraception. A detailed analysis of the fertility of these women showed no significant altitude‐related differences in the number of live births. However, as a result of significantly higher childhood mortality rates at altitude, there was a significant reduction in numbers of living children. The results of this study suggest that the collection and analysis of census data that ignores socioeconomic differences within a population or differences among census units in neonatal or early childhood mortality may bias or complicate the study of the impact of altitude on human fertility. Although the present research does not prove that hypoxic stress does not affect the reproductive system, the results suggest that if altitude does reduce fecundity, the reduction is not great and is likely to be shown only through studies of reproductive physiology.     

福建柏开花与结实物候期的研究

福建柏1年2次花期,春花期4—5月,果期当年10月,种子无生活力;秋花期9～10月,果期翌年10月,种子有生活力,有效花期在秋季。开花结实的生物学及物候学特性与适生区的地点、地类、海拔、温度等地理气候因子紧密相关,总体变异规律：秋花期、球果成熟期、种子散落期山区比半山区早,半山区比丘陵区早,高海拔地区比低海拔地区早．发芽率山区〉半山区〉丘陵区。     

Soil organic carbon stock and chemical composition along an altitude gradient in the Lushan Mountain,subtropical China

Soil organic carbon (SOC) stock in mountain ecosystems is highly heterogeneous because of differences in soil, climate, and vegetation with elevation. Little is known about the spatial distribution and chemical composition of SOC along altitude gradients in subtropical mountain regions, and the controlling factors remain unclear. In this study, we investigated the changes in SOC stock and chemical composition along an elevation gradient (219, 405, 780, and 1268 m a.s.l.) on Lushan Mountain, subtropical China. The results suggested that SOC stocks were significantly higher at high altitude sites (1268 m) than at low altitude ones (219, 405, and 780 m), but the lower altitude sites did not differ significantly. SOC stocks correlated positively with mean annual precipitation but negatively with mean annual temperature and litter C/N ratio. The variations in SOC stocks were related mainly to decreasing temperature and increasing precipitation with altitude, which resulted in decreased litter decomposition at high altitude sites. This effect was also demonstrated by the chemical composition of SOC, which showed lower alkyl C and higher O-alkyl C contents at high altitude sites. These results will improve the understanding of soil C dynamics and enhance predictions of the responses of mountain ecosystem to global warming under climate change.     

The Bourgeois-Pichat's biometric method and the influence of climate: new evidences from late 19th-century Italy

This paper examines to which extent seasonal and climatic conditions might affect the reliability of the Bourgeois-Pichat's method. Other scholars have already argued on this issue, but although climate has often been claimed to explain part of the differentials in mortality figures among Italian regions, to date its impact has not actually been recognized and quantitatively evaluated. To test such hypothesis data at the regional level from late 19th-century Italy have been analyzed. Our analysis of the biometric components revealed a strong bias in the estimates of the endogenous and exogenous components in the first month of life. Variations in infant mortality among Italian regions correlated with variations in the endogenous levels rather than in the exogenous levels of infant (neonatal) mortality, as it was expected owing to the infective nature of the diseases climate might induce. Specifically, Northern and colder regions featured high figures for both neonatal mortality and the endogenous component, while the opposite scheme applied to the Southern, more temperate regions. Finally, the reasons for such misleading results were investigated. It emerged that the model's assumption of a constant and invariant proportion of neonatal exogenous deaths to the total amount of exogenous deaths was not matched by the Italian data. This situation caused the excess neonatal exogenous mortality, especially that induced by cold climate in Northern regions, to be wrongly counted in the endogenous component.     

The relationship between socioeconomic status and infant mortality in metropolitan Ohio, 1999–2001

Abstract

Empirical evidence has consistently documented the direct relationship between infant mortality and socioeconomic inequality in the United States and numerous other countries. While the majority of these studies reveal an inverse relationship between socioeconomic level and infant mortality, not even this finding is free from disagreement. Furthermore, the specific nature and magnitude of this relationship has varied over time.

This study will examine the relationship between socioeconomic status and infant mortality in metropolitan Ohio by using birth and infant death data centered on the 2000 Census. The analyses presented herein will describe and analyze the relationship between infant mortality and socioeconomic status in metropolitan Ohio in the year 2000. The key finding is that in spite of remarkable declines in infant mortality during the past several decades, most notably in neonatal mortality, there continues to be a pronounced inverse association between the infant death rate and the economic status of a population.     

Infant mortality in Zambia: socioeconomic and demographic correlates

Trends in infant mortality in Zambia suggest a reversal of the decline experienced between the 1960s and the late 1970s. From a high of about 140, infant mortality rate declined to about 90 in the late 1970s only to rise again to 100 by 1996. Data on 5,600 births born between 1987 and 1992, and 6,630 births between 1991 and 1996 from the Zambian DHS are analyzed to identify socioeconomic and demographic correlates of infant mortality. Demographic factors such as small size at birth and short birth intervals are associated with higher neonatal mortality. In the post-neonatal period, urban children from poorer households had the highest mortality between 1991-1996. Also, differences in infant mortality rates between provinces narrowed. Children born in the most developed province of Lusaka had as high of risk of dying as those from Luapula, a province with a history of extremely high mortality rates in Zambia.     

Birth defects in India: Hidden truth,need for urgent attention

Birth defects (structural, functional and metabolic disorder present from birth, may be diagnosed later) rising up as an important cause of infant mortality even in developing countries where infant mortality has been reduced to much extent. Seventy percent of birth defects are preventable through the application of various cost effective community genetic services.Indian people are living in the midst of risk factors for birth defects, e.g., universality of marriage, high fertility, large number of unplanned pregnancies, poor coverage of antenatal care, poor maternal nutritional status, high consanguineous marriages rate, and high carrier rate for hemoglobinopathies. India being the second most populous country with a large number infant born annually with birth defects should focus its attention on strategies for control of birth defects. Many population based strategies such as iodization, double fortification of salt, flour fortification with multivitamins, folic acid supplementation, periconceptional care, carrier screening and prenatal screening are some of proven strategies for control of birth defects. Strategies such as iodization of salt in spite of being initiated for a long time in the past do have a very little impact on its consumption (only 50% were using iodized salt). Community genetic services for control of birth defects can be easily flourished and integrated with primary health care in India because of its well established infrastructure and personnel in the field of maternal and child health care. As there is wide variation for infant mortality rate (IMR) in different states in India, so there is a need of deferential approach to implement community genetic services in states those had already achieved national goal of IMR. On the other hand, states those have not achieved the national goal on IMR priority should be given to management of other causes of infant mortality.     

Effects of altitude and competition on growth and mortality of the conifer Abies sachalinensis

Altitudinal gradients are convenient subjects to investigate plant responses to air temperature. Plant growth and mortality are also affected by competition at any altitude. This study investigated the effects of altitude and competition on absolute diameter growth rate (ADGR) and mortality of the conifer Abies sachalinensis by using 13-year data. This study was done at two altitudes (200 and 1,000 m a.s.l.) in northern Japan. Local crowding by conifers and broad-leaved trees reduced ADGR of target trees. ADGR was lower in high altitude than low altitude at any DBH and any degree of local crowding because of the short growing season. Observed size-dependent mortality was a U-shaped pattern against DBH at the two altitudes. Smaller and larger trees tended to die of suppression (standing-dead) and disturbances (stem-broken and uprooting), respectively. Mortality of standing-dead trees was negatively correlated with ADGR, irrespective of altitude, i.e., ADGR was a good predictor of mortality. Thus, mortality of standing-dead trees was estimated to be greater at high altitude than low altitude at any degree of local crowding because ADGR was lower at high altitude than low altitude. By contrast, mortality due to disturbances was slightly greater at low altitude than high altitude. Thus, this study showed that a short growth period decreases growth and increases mortality due to suppression at high altitude. Although global warming may increase growth and survival of individual trees at high altitude by prolonging the growth period, prediction on mortality due to disturbances needs caution because the mortality is largely affected by frequency and intensity of disturbances.     

The bourgeois‐pichat's biometric method and the influence of climate: New evidences from late 19th‐century Italy

Abstract

This paper examines to which extent seasonal and climatic conditions might affect the reliability of the Bourgeois‐Pichat's method. Other scholars have already argued on this issue, but although climate has often been claimed to explain part of the differentials in mortality figures among Italian regions, to date its impact has not actually been recognized and quantitatively evaluated. To test such hypothesis data at the regional level from late 19^th‐century Italy have been analyzed.

Our analysis of the biometric components revealed a strong bias in the estimates of the endogenous and exogenous components in the first month of life. Variations in infant mortality among Italian regions correlated with variations in the endogenous levels rather than in the exogenous levels of infant (neonatal) mortality, as it was expected owing to the infective nature of the diseases climate might induce. Specifically, Northern and colder regions featured high figures for both neonatal mortality and the endogenous component, while the opposite scheme applied to the Southern, more temperate regions.

Finally, the reasons for such misleading results were investigated. It emerged that the model's assumption of a constant and invariant proportion of neonatal exogenous deaths to the total amount of exogenous deaths was not matched by the Italian data. This situation caused the excess neonatal exogenous mortality, especially that induced by cold climate in Northern regions, to be wrongly counted in the endogenous component.     

THE OBSTETRICIAN'S RESPONSIBILITY IN INFANT MORTALITY

Although infant mortality has been remarkably reduced, stillbirth and neonatal death rates have been improved very little. Efforts at lowering the fetal death rate must be directed to those conditions affecting the fetus during labor or immediately afterward.Prevention of premature labor and better care of the premature infant during labor and the neonatal period offer hope of a greater salvage of premature infants. Proper environment and trained personnel are necessary.Spontaneous delivery is safest for the infant. Difficult operative procedures are associated with a high incidence of birth trauma, asphyxia and death.Since asphyxia is one of the chief causes of infant death, prevention, diagnosis and treatment of it are most important. Administration of oxygen to mildly asphyxiated infants before the injury has become irreversible may help to prevent late manifestations of anopia.     

Biomass and diversity of dry alpine plant communities along altitudinal gradients in the Himalayas

A non-linear relationship between phytodiversity and altitude has widely been reported, but the relationship between phytomass and altitude remains little understood. We examined the phytomass and diversity of vascular plants along altitudinal gradients on the dry alpine rangelands of Ladakh, western Himalaya. We used generalized linear and generalized additive models to assess the relationship between these vegetation parameters and altitude. We found a hump-shaped relationship between aboveground phytomass and altitude. We suspect that this is engendered by low rainfall and trampling/excessive grazing at lower slopes by domestic livestock, and low temperature and low nutrient levels at higher slopes. We also found a unimodal relationship between plant species-richness and altitude at a single mountain as well as at the scale of entire Ladakh. The species-richness at the single mountain peaked between 5,000 and 5,200 m, while it peaked between 3,500 and 4,000 m at entire Ladakh level. Perhaps biotic factors such as grazing and precipitation are, respectively, important in generating this pattern at the single mountain and entire Ladakh.     

Optimal birthweights in Peruvian populations at high and low altitudes

This study tests the hypothesis that optimum birthweight for survival is lower among hospital-born infants in Puno, Peru (altitude 3860 m) than that among their counterparts at low altitude in Tacna, Peru (altitude 600 m). The data are derived from hospital birth records for 1971 and 1972 and municipal death records for 1971 through 1973. Linking these records permits analysis of the patterns of mortality in relation to birthweight. Stabilizing selection upon birthweight is operating in both populations. The high altitude population has a lower mean birthweight and a lower optimal birthweight. The Puno population is closer to its optimal birthweight distribution and, as a result of mortality during infancy, is approaching its optimum birthweight distribution for survival more rapidly than the Tacna population. It appears that the high altitude Puno population may well be adapted to its environment in the sense that there is less selective mortality on birthweight phenotypes.     

Teenage fertility, socioeconomic status and infant mortality

This paper examines the relationship between infant mortality and a complex measure of socioeconomic status for evidence of diminution. In data on counties in the US with a minimum of 20 infant deaths over the 5-year period 1971-75, no evidence of a declining relationship between socioeconomic status and infant mortality was found. Both level of community affluence and racial composition of the population exerted direct effects on levels of infant deaths. In addition, both socioeconomic status and racial composition exhibited indirect effects which operated through teenage childbearing. When total infant mortality was subdivided, teenage fertility serves as a mediating variable in the link between socioeconomic status and neonatal mortality, but not for the postneonatal components. Given the nearly equivalent total effect of socioeconomic status on infant mortality, it is concluded that the classic division into neonatal (supposedly a function of biological and genetic agents) and postneonatal (traditionally attributed to social and environmental agents), may be too crude to allow the contemporary effects of the socioenvironmental milieu to be evaluated effectively.