Trend in cerebral palsy birth prevalence in eastern Denmark: birth-year period 1979–86

To investigate changes in cerebral palsy birth prevalence and perinatal mortality rate by different gestational age groups, 1979–86, cerebral palsy cases in eastern Denmark were identified from the Danish Cerebral Palsy Register, and information on birth and mortality rates was sought in the Danish Medical Birth Register. From 1979–82 to 1983–86, the birth prevalence of cerebral palsy increased from 2.6 to 3.0 per 1000 ( P  < 0.05). The rate for infants of 31 weeks' gestation or more did not change, whereas a significant increase was observed in infants below 31 weeks (85–123 per 1000, P  < 0.05). In the same periods, perinatal mortality in eastern Denmark decreased significantly from 8.6 to 7.8 per 1000. The decrease in stillbirth rate was significant in all subgroups of gestational ages except in those of 28–30 weeks' gestation. The early neonatal mortality rate decreased significantly only in infants below 31 weeks (282–239 per 1000, P  < 0.05). Thus, in eastern Denmark, cerebral palsy birth prevalence has increased from birth-year period 1979–82 to 1983–86 because of an increased rate in preterm infants below 31 weeks, who at the same time had a reduced risk of early neonatal death.     

Healthier mothers and babies

At the beginning of the 20th century, for every 1000 live births, six to nine women in the United States died of pregnancy-related complications, and approximately 100 infants died before age 1 year. From 1915 through 1997, the infant mortality rate declined >90% to 7.2 per 1000 live births, and from 1900 through 1997, the maternal mortality rate declined almost 99% to <0.1 reported death per 1000 live births (7.7 deaths per 100,000 live births in 1997). Environmental interventions, improvements in nutrition, advances in clinical medicine, improvements in access to health care, improvements in surveillance and monitoring of disease, increases in education levels, and improvements in standards of living contributed to this remarkable decline. Despite these improvements in maternal and infant mortality rates, significant disparities by race and ethnicity persist. This report summarizes trends in reducing infant and maternal mortality in the United States, factors contributing to these trends, challenges in reducing infant and maternal mortality, and provides suggestions for public health action for the 21st century.     

Beri-beri: the major cause of infant mortality in Karen refugees

During a prospective evaluation of malaria prophylaxis in pregnancy in a refugee population on the north-western border of Thailand from 1987 to 1990, an extremely high infant mortality rate (18%) was documented despite good access to health care. Infantile beri-beri was recognized as the main cause of death accounting for 40% of all infant mortality. Thereafter, severe vitamin B1 deficiency in infants was diagnosed and treated promptly. The impact of this was assessed prospectively from 1993 to 1996 in a second cohort study. The case fatality of infantile beri-beri fell from almost 100% to 7%. The overall infant mortality rates declined from 183 to 78 per 1000 live births. Post-neonatal deaths fell by 79% (95% CI 65-87%) while neonatal mortality remained unchanged. Mortality resulting from acute respiratory infections did not change (15 and 11 per 1000, respectively), whereas mortality attributable to beri-beri decreased from 73 to 5 per 1000 (P < 0.0001). Before its recognition approximately 7% of all infants in this population died from infantile beri-beri. This lethal but preventable syndrome may be more common than hitherto recognized, particularly in refugee populations, in this populous region.     

四川省2001-2009年婴儿死亡率变化趋势及死因分析

目的 了解2001-2009年四川省婴儿年龄别和主要死因别死亡率的变化趋势.方法 采用四川省5岁以下儿童死亡监测收集的2001-2009年监测点儿童死亡资料,计算城乡新生儿、婴儿死亡率及婴儿死因别死亡率.结果 2009年四川省新生儿、婴儿死亡率分别为7.6‰和12.1‰,较2001年(18.6‰和25.5‰)分别下降了...     

Trends and regional variations in infant mortality rates in Japan, 1973-1998

OBJECTIVE: The purpose of the study was to investigate the trends and regional variations in infant mortality rates in Japan. METHOD: The data from 1973 to 1998 analysed in this paper were from the Vital Statistics Division, Ministry of Health, Labor and Welfare of Japan. RESULTS: Infant mortality rates declined significantly between 1973 and 1998 in all regions. Statistically significant differences in infant mortality rates among the regions were observed in 1973, 1974, 1976, 1977 and 1978. However, the regional differences in infant mortality rates were insignificant thereafter, indicating elimination of regional variations in infant mortality in Japan. CONCLUSION: The results of this study indicated declines in infant mortality rates in all regions, with elimination of regional variations in infant mortality in Japan in the last two decades. This may be attributable to both qualitative and quantitative improvements in health and medical services in Japan.     

婴儿死亡率与新生儿死亡比的关系

目的:探讨婴儿死亡率与新生儿死亡比的关系及成因。方法:从WHO死亡数据库、人口数据库中收集婴儿死亡数、新生儿死亡数和活产数等数据,利用各国的婴儿死亡率-新生儿死亡比散点图分析、归纳两指标的关系,并通过对美国数据的分析探讨成因。结果:入选国家的婴儿死亡率与新生儿死亡比之间是一种曲线关系,随婴儿死亡率的下降,新生儿死亡比先上升至峰值(大致位置:婴儿死亡率为11.42‰、新生儿死亡比为70.32%),后下降至谷值(大致位置:婴儿死亡率为4.86‰、新生儿死亡比为61.22%),再上升。由于各国记录中婴儿死亡率范围的限制,各国散点图都只是完整曲线的一部分。美国新生儿期、新生儿后期主要死因别死亡率的变化导致新生儿期、新生儿后期死亡率大小关系发生变化,进而导致婴儿死亡率与新生儿死亡比呈现曲线关系。结论:婴儿死亡率与新生儿死亡比之间是一种曲线关系,出现原因可能为新生儿期、新生儿后期主要死因别死亡率的变化。婴儿死亡率较低(<11.42‰)的国家和地区需谨慎使用"婴儿死亡率与新生儿死亡比成负相关"的观点。     

Infant mortality among First Nations versus non-First Nations in British Columbia: temporal trends in rural versus urban areas, 1981-2000

BACKGROUND: Increasingly more First Nations (FN) people have moved from rural to urban areas. It is unknown how disparities in infant mortality among FN versus non-FN women have changed over time in urban versus rural areas. METHODS: We conducted a birth cohort-based study of all 877 925 live births (56 771 FN and 821 154 non-FN) registered in British Columbia, 1981-2000. Main outcomes included rates, risk differences, and relative risks of neonatal, postneonatal, and overall infant death. RESULTS: Both neonatal and postneonatal mortality rates for FN infants showed a steady decline in rural areas but a rise-and-fall pattern in urban areas. Relative risks for overall infant death among FN versus non-FN infants declined steadily from 2.75 (95% CI: 2.04, 3.72) to 1.87 (95% CI: 1.24, 2.81) in rural areas from 1981-1984 to 1997-2000, but rose from 1.59 (95% CI: 1.27, 1.99) (1981-1984) to 2.80 (2.33-3.37) (1989-92) and then fell to 1.89 (1.44-2.49) (1997-2000) in urban areas. Risk differences for neonatal death among FN versus non-FN infants declined substantially over time in rural but not urban areas. The disparities in neonatal death among FN versus non-FN were largely explained by differences in preterm birth, while the disparities in postneonatal death were not explained by observed maternal and pregnancy characteristics. CONCLUSIONS: Reductions in disparities in infant mortality among FN versus non-FN women have been less substantial and consistent over time in urban versus rural areas of British Columbia, suggesting the need for greater attention to FN maternal and infant health in urban areas.     

北京市海淀区围生儿死亡状况动态分析

目的探讨北京市海淀区围生儿死亡变化规律和主要死亡原因。方法资料来源于北京市围生儿死亡监测网,采用以人群为基础的监测方法。围生儿死亡数据来源于分娩医院或地段保健科填写的北京市围生儿死亡报告卡。结果海淀区1997~2005年平均围生儿死亡率7.09‰,由1997年的8.22‰降至2005年的4.24‰;早期新生儿死亡率由1997年的3.82‰降至2005年的2.01‰。围生儿死亡和早期新生儿死亡的首位死因均为出生缺陷,早期新生儿死亡中出生缺陷死亡专率呈下降趋势。结论海淀区围生儿死亡率降低主要是早期新生儿死亡率降低所致,早期新生儿死亡率降低的主要原因是围生期的出生缺陷儿减少。     

Mortality trends among refugees in Honduras, 1984-1987

Mortality data collected from 1984 to 1987 through a routine standardized health information system in the five main refugee populations of Honduras were reviewed. The direct standardized mean annual death rate for all refugees was 5.5 per 1000 population (Honduras population as reference; Honduras mortality rate: 10.1 per 1000). Mortality decreased or remained stable among Salvadoran refugees from 1984 to 1987, but increased among Nicaraguan refugees after 1985. The highest neonatal (56.1 per 1000 livebirths), infant (126.1 per 1000 livebirths) and under-five-year-olds (35.7 per 1000 child less than five years of age) mortality rates were observed in the two Nicaraguan camps. These two camps had the highest rate of newly arriving refugees. Deaths in infants and under-five-year-olds accounted for 42 and 54.1% of all deaths respectively. Of all deaths under five years of age, respiratory infections, diarrhoeal diseases and measles accounted for 21.4%, 22.1% and 4.7%, respectively. Mortality rates, particularly among under-five-year-olds and infants increased when the rate of newly arriving refugees was higher. The importance of adapted health surveillance in refugee settlements is discussed.     

Decline in birthweight-specific infant mortality rates of singleton livebirths in the 1990s in Japan

OBJECTIVE: This study investigated the decline in birthweight-specific infant mortality rates in Tohoku, Tokai and Kyushu regions between 1989 to 1990 and 1995 to 1998. METHODS: Information for both births and infant deaths from any diseases were collected for two periods in the Tohoku, Tokai and Kyushu regions. The first involved a cohort of singleton livebirths (n = 404, 158) in the three regions in 1989, whose birth certificates were linked with infant death certificates. The second was for singleton livebirths (n = 1,503,230) in the same regions between 1995 and 1998, and infant deaths from any diseases were identified based on vital statistics. RESULTS: Overall infant mortality rate from any diseases declined 16%, from the 3.86/1000 of the first group to the 3.24/1000 of the second group. A shift to a lower birthweight distribution weakened the improvement in the overall mortality rate, so that birthweight standardized mortality rates were reduced more than crude ones. Based on birthweight adjusted relative risk, neonatal, postneonatal and infant mortality rates for each birthweight group were improved by almost uniform ratio, that is 31%, 12% and 23% respectively. Improvement of survival of infants with birthweight of a 2500 or more accounted for most of the decline in the infant mortality rates in the 1990s. Mortality rates from "certain conditions originating in the perinatal period" and "congenital anomalies" decreased remarkably, whereas the sudden infant death syndrome increased. CONCLUSIONS: We conclude that reduction of mortality rates in the infant period in Japan in the 1990s was attributable to decline in birthweight-specific mortality rates and weakened by a shift to a lower birthweight distribution over time. Normal birthweight infants showed the greatest improvement.     

Cause-Specific Trends in Neonatal Mortality Among Black and White Infants,United States, 1980–1995

Objective: Although neonatal mortality has been declining more rapidly than postneonatal mortality in recent decades, neonatal mortality continues to account for close to two-thirds of all infant deaths. This report uses U.S. vital statistics data to describe national trends in the major causes of neonatal mortality among black and white infants from 1980 to 1995. Methods: Mortality rates were estimated as the number of deaths due to each cause (based on International Classification of Diseases, 9th Revision, codes) divided by the number of live births during the same time period. Linear regression models and smoothed rates were used to describe trends. Results: During the study period, neonatal mortality declined 4.0% per year for white infants and 2.2% per year for black infants, and the black–white gap increased from 2.0 to 2.4. By 1995, disorders relating to short gestation and low birth weight were the number one cause of neonatal death for black infants and the number two cause for white infants, had the highest black–white disparity (4.6, up from 3.3 in 1980), and accounted for almost 40% of excess deaths to black infants (up from 24% in 1980). Congenital anomalies were the number two cause of neonatal death for black infants and the highest ranked cause for white infants in 1995, and it is the only cause for which there was not a substantial excess risk to black infants. Conclusions: Large declines in neonatal mortality have been achieved in recent years, but not in the black–white gap, which has increased. Declines were slower for black than white infants overall and for almost all causes. Prevention of preterm delivery and low birth weight continue to be a priority for reducing neonatal mortality, particularly among black infants. Although congenital anomalies do not contribute substantially to the black–white gap, their diagnosis, treatment, and prevention is critical to reducing overall neonatal mortality.     

Trends and Racial Differences in Birth Weight and Related Survival

Objective: In the past two decades, infant mortality rates in the United States declined in African-American and White populations. Despite this, racial disparities in infant mortality rates have increased and rates of low birth weight deliveries have shown little change. In this study, we examine temporal changes in birth weight distributions, birth weight specific neonatal mortality, and the birth weight threshold for an adverse risk of survival within both racial groups in order to explore the mechanisms for the disparities in infant mortality rates. Method: Single live births born to South Carolina resident mothers between 1975 and 1994 and considered White or African-American based on the mother's report of maternal race on the birth certificate were selected for investigation. We define the birth weight threshold for adverse survival odds as the birth weight at which 50% or more of infants in the population died within the first month of life. Results: Despite significant increases in very low birth weight percentages, neonatal mortality rates markedly declined. Birth weight specific neonatal mortality decreased for both races, although greater reductions accrued to White low birth weight infants. By the end of the study period, the birth weight at which over 50% of newborns died within the first month of life was 696 g for Whites and 673 g for African-Americans. Discussion: The ongoing decline in neonatal mortality is mainly due to reductions in birth weight specific neonatal mortality, probably related to high-risk obstetric and neonatal care. Technological developments in these areas may have differentially benefited Whites, resulting in an increasing racial disparity in mortality rates. Moreover, the relatively greater and increasing mortality risk from postmaturity and macrosomia in infants of African-America mothers may further exacerbate the racial gap in infant mortality.     

Stillbirth and infant mortality in singletons by cause of death,birthweight, gestational age and birthweight‐for‐gestation,Newcastle upon Tyne 1961–2000

Glinianaia SV, Rankin J, Pearce MS, Parker L, Pless‐Mulloli T. Stillbirth and infant mortality in singletons by cause of death, birthweight, gestational age and birthweight‐for‐gestation, Newcastle upon Tyne 1961–2000. Paediatric and Perinatal Epidemiology 2010. The dramatic reduction observed in stillbirth and infant mortality over the last few decades has not been assessed by both birthweight and gestation. We have explored temporal changes in stillbirth and infant mortality in Newcastle upon Tyne, UK, by cause of death, birthweight, gestational age, birthweight standardised for gestation and infant sex during 1961–2000. We included 131 044 singleton births to mothers resident in Newcastle, including 1342 stillbirths and 1620 infant deaths. Cause‐, birthweight‐, gestational age‐ and birthweight‐for‐gestation‐specific stillbirth (per 1000 total births) and infant mortality (per 1000 livebirths) rates were compared between 1961–80 and 1981–2000 and between individual consecutive decades. Between 1961 and 2000, total stillbirth and infant mortality rates declined dramatically from 23.4 to 4.7 per 1000 total births and from 25.7 to 5.9 per 1000 livebirths, respectively. Rates fell continuously during the first two study decades; however, from 1981–90 to 1991–2000 the decline was not statistically significant. Between 1961–80 and 1981–2000, both stillbirth and infant mortality significantly declined in all birthweight and gestational age categories and for most leading causes of death. Although the population mean birthweight during 1981–2000 [3304 g (SD ± 569)] was significantly higher than during 1961–80 [3255 g (SD ± 572)] (P < 0.0001), the lowest stillbirth and infant mortality rates in 1981–2000 were consistently at about 1 SD above the mean birthweight, with mortality rates increasing for babies with lower or higher weight‐for‐gestation. Declines in stillbirth and infant mortality in Newcastle were associated with reductions in birthweight‐ and gestational age‐specific mortality rates and occurred in most cause‐specific groups of death.     

Impact of increased neonatal survival on postneonatal mortality in the United States

Summary. Neonatal intensive care has increased neonatal survival, but has also led to postponement of some of the neonatal deaths to the postneonatal period, particularly in very low birthweight (<1.5kg) infants. Our report assesses the impact of the increased neonatal survival and the accompanying delayed deaths on the crude postneonatal mortality rate oi the US, using the national livebirth cohort data of 1960,1980, and 1986. With increased neonatal survival, very low birthweight infants comprised 0.68% of all neonatal survivors in 1986, compared with only 0.31% in 1960. However, postneonatal mortality was increased in infants with birth weights < 1.0 kg from 69 per 1000 neonatal survivors in 1960 to 116 per 1000 in 1986. All other birthweight groups (> 1.0 kg) showed significant reductions in their postneonatal mortality, although the 1.0–1.5 kg group showed the least improvement. Thus, in 1986, 12.1% of all postneonatal deaths were from the very low birthweight neonatal survivors, as compared with 2.7% in 1960. If there had been no improvement in neonatal survival of very low birthweight infants since 1960, the crude postneonatal mortality rate of the US would have been 5.5% and 7.9% less than the actual rates of 3.65 and 3.45 per 1000 neonatal survivors in 1980 and 1986, respectively. However, the impact of these delayed deaths in very low birthweight infants was far less than the increase in their neonatal survival: an additional 416 per 1000 very low birthweight infants survived to 1 year of age in 1986 as compared with 1960. Delayed deaths in the 1.5-2.5 kg birthweight group had a very small effect on postneonatal mortality and there was no such effect of delayed deaths in the > 2.5 kg birthweight group.     

Risk factors for infant mortality from diseases in Japan 1995-98

OBJECTIVE: Since 1995, additional information (i.e. birth weight, singleton/multiple births, gestational weeks, maternal age, maternal parity and stillbirth experience) has been required for certificates of infant (less than 1 year of age) death from diseases in Japan. The present study examined the effects of biological, demographic and social variables, as reported on birth and death certificates, on infant, neonatal and postneonatal mortality in Japan. METHODS: Using data from vital statistics between 1995 and 1998, more than 4,787,000 livebirths and 16,000 infant deaths from diseases were analyzed. Univariate and multivariate analyses with the Poisson regression model were employed to assess the effects of variables on infant, neonatal and postneonatal mortality by singleton and multiple livebirths separately. RESULTS: The infant mortality rates from diseases were 3.2/1000 for singleton livebirths and 17.7/1000 for multiple livebirths. In singleton livebirths, low birth weight, infant born in earlier years, being a male infant, employment status as "unemployed or unknown", short gestational weeks, late birth in multiparity and maternal stillbirth experience were all significantly related to increased risk of neonatal and postneonatal deaths. Teenage mother were also at high risk of postneonatal deaths. Regional differences were observed. Compared with singleton livebirths, birthweight-specific mortality rates in multiple livebirths were relatively low among infants weighing under 2500 g. In multiple livebirths, elevated risk of death was associated with low birth weight, infant born in earlier years, employment status as "unemployed or unknown" and short gestational weeks. However, late birth in multiparity was related to a reduced risk of death, and maternal stillbirth experience was not a significant variable. CONCLUSION: This study provided the first quantitative estimate of risk of infant mortality from diseases in Japan. Since a more detailed elucidation of actual conditions and risk factors of infant deaths by vital statistics has become possible, efficient measures for improvement of infant mortality are to be expected.     

Cerebral palsy births in eastern Denmark, 1987--90: implications for neonatal care

The Cerebral Palsy Register in eastern Denmark has collected cases using a uniform data sampling procedure since birth year 1979. We have investigated changes in the rate of cerebral palsy, related to gestational age, mortality and perinatal risk factors in children born 1983--90. The total cerebral palsy birth prevalence decreased from 3.0 in the birth year period 1983--86 to 2.4 per 1000 live births (P < 0.01) in 1987--90, owing to a decrease among all preterm infants (29--19 per 1000, P < 0.001). The perinatal and early neonatal mortality in preterm infants was unchanged from 1983--86 to 1987--90. The rate of cerebral palsy in term infants was 1.5 per 1000 in all birth-year periods from 1979--90. Among the cerebral palsy infants, the proportion of very preterm babies treated with mechanical ventilation in the neonatal period decreased from 95% in 1983--86 to 61% in 1987--90 (P < 0.001), while the group treated with CPAP among the moderately preterm babies increased from 61% to 78% (P < 0.05). The significant decline in cerebral palsy rate in preterm infants born 1987--90 may be due to a change in treatment at the neonatal intensive care units using less mechanical ventilation, a hypothesis which needs further investigation.     

Social determinants for infant mortality in the Nordic countries, 1980-2001

AIM: Social equity in health is an important goal of public health policies in the Nordic countries. Infant mortality is often used as an indicator of the health of societies, and has decreased substantially in the Nordic welfare states over the past 20 years. To identify social patterns in infant mortality in this context the authors set out to review the existing epidemiological literature on associations between social indicators and infant mortality in Denmark, Finland, Norway, and Sweden during the period 1980-2000. METHODS: Nordic epidemiological studies in the databases ISI Web of Science, PubMed, and OVID, published between 1980 and 2000 focusing on social indicators of infant, neonatal, and postneonatal mortality, were identified. The selected keywords on social indicators were: education, income, occupation, social factors, socioeconomic status, social position, and social class. RESULTS: Social inequality in infant mortality was reported from Denmark, Finland, Norway, and Sweden, and it was found that these increased during the study period. Post-neonatal mortality showed a stronger association with social indicators than neonatal mortality. Some studies showed that neonatal mortality was associated with social indicators in a non-linear fashion, with high rates of mortality in both the lowest and highest social strata. The pattern differed, however, between countries with Finland and Sweden showing consistently less social inequalities than Denmark and Norway. While the increased inequality shown in most studies was an increase in relative risk, a single study from Denmark demonstrated an absolute increase in infant mortality among children born to less educated women. CONCLUSIONS: Social inequalities in infant mortality are observed in all four countries, irrespective of social indicators used in the studies. It is, however, difficult to draw inferences from the comparisons between countries, since different measures of social position and different inclusion criteria are used in the studies. Nordic collaborative analyses of social gradients in infant death are needed, taking advantage of the population-covering registers in longitudinal designs, to explore the mechanisms behind the social patterns in infant mortality.