Perinatal and infant mortality

Australia's infant mortality rate fell below 10/1000 live births for the 1st time in 1983 (9.6/1000). Internationally, Australia ranks 12th in infant mortality among countries with populations over 2.5 million. Contributing to this relatively poor international standing has been the high incidence of low birthweight infants, high postneonatal mortality in disadvantaged population groups such as the Aborigines, and the completeness of registration of infant mortality in Australia. There is a legal requirement that perinatal deaths from at least 20 weeks gestation or 400 gm birthweight be registered. In 1983, the national perinatal mortality rate was 12.2/1000 births. The greatest reduction in neonatal mortality has been among infants weighing 1000-2499 gms. Most of the recent improvement in the low birthweight component of the neonatal death rate is attributable to the better survival of these infants, not a major reduction in the incidence of low birthweight. Several proposals are made for improving the data on perinatal and infant mortality in Australia. These deaths should be routinely linked to the maternal and fetal or neonatal data in the perinatal morbidity data collections to facilitate identification of risk factors. Also, pregnancies terminated after diagnosis of fetal abnormalities should be included in these perinatal data collections. Steps such as educating the community about the adverse effects of alcohol and smoking in pregnancy, increased planning of pregnancy, better detection of high risk pregnancies, and regionalization of the care of pregnant women at high risk of complications could contribute to further reductions in infant and perinatal mortality in Australia.     

Postponing or preventing deaths? Trends in infant survival, Georgia, 1974 through 1981

Trends in survival were examined for infants in five birth-weight groups (500 to 999 g, 1,000 to 1,499 g, 1,500 to 1,999 g, 2,000 to 2,499 g, and greater than or equal to 2,500 g). The study population consisted of infants born in Georgia from 1974 through 1981. Survival to the first birthday increased for all birthweight groups. Improvements in postneonatal survival occurred concurrently with improvements in neonatal survival, except for infants with birth weights of 500 to 999 g. Between 1974-1975 and 1980-1981, the proportion of deaths that were attributed to perinatal conditions but occurred during the postneonatal period increased from 1.1% to 4.7%. These observations suggest that advances in perinatal care have led to postponement rather than prevention of a few infant deaths, although overall many more deaths were prevented. For infants with birth weights of less than 1,500 g, lower mortality among those admitted to newborn intensive care units was the major contributor to improved survival. Our findings indicate that both neonatal and postneonatal mortality should be examined in evaluating the effects of perinatal care.     

Perinatal and postneonatal mortality among Indigenous and non-Indigenous infants born in Western Australia, 1980-1998

OBJECTIVE: To describe cause-specific perinatal and postneonatal mortality for Indigenous and non-Indigenous infants using a new classification system. DESIGN: Total population retrospective cohort study. PARTICIPANTS AND SETTING: All registered births in Western Australia of birthweight greater than 399 g from 1980 to 1998, inclusive. MAIN OUTCOME MEASURES: Rates and time trends for all births 1980-1998, and cause-specific rates for births 1980-1993 of fetal, neonatal and postneonatal mortality among Indigenous and non-indigenous infants, using a classification system designed for use in perinatal, postneonatal and childhood deaths. RESULTS: For Indigenous infants born 1980-1998, the mortality rate before the first birthday was 2.7 times (95% CI, 2.5-2.9 times) that for non-Indigenous infants. Indigenous infants born 1980-1993 had a higher mortality rate in all cause-of-death categories. The highest relative risk was for deaths attributable to infection (8.1; 95% CI, 6.5-10.0) which occurred primarily in the postneonatal period; the source of the infection was less likely to be identified in Indigenous deaths. From 1980-1998, the rate of neonatal deaths decreased at a greater rate for Indigenous than for non-Indigenous infants. However, while stillbirth and sudden infant death syndrome rates for non-Indigenous births fell, they remained static for Indigenous births. CONCLUSIONS: The new classification system, which considers the underlying rather than immediate cause of death, enables investigation of the causes of all deaths, from stillbirths to childhood. This system has highlighted the comparative importance of infection as a cause of death for Indigenous infants, particularly in the postneonatal period.     

Postneonatal deaths in North Carolina, 1959-1963

The data presented indicate that the disturbing upward trend in infant mortality in North Carolina has been arrested and possibly reversed during the 1959 through 1963 period. Information obtained from death certificates indicates that infections accounted for slightly more than half (52.4%) of the postneonatal deaths occurring in the study periods. The most common type of infection was influenza and pneumonia, followed by gastroenteritis and colitis, infective and parasitic disease, meningitis, and acute respiratory infections, in that order of frequency. Infections were responsible for a greater percentage of the postneonatal deaths among nonwhite (58.5%) than amon white infants (40.7%). the postneonatal death rate from infections was 13.4 for nonwhite infants and 2.2 for white infants. The next most common cause of postneonatal mortality -- congenital malformations -- was relatively more important in the white race, being responsible for approximately 25% of white deaths and only 6% of nonwhite deaths. I11 defined and unknown causes ranked 3rd in importance, with postneonatal death rates of 3.0 for nonwhite and .4 for white infants. Accidents, wich ranked 4th, were responsible for approximately 10% of the postneonatal deaths in each race. In both races, the risk of postneonatal death was greater in infants born to younger mothers, partiuclarly those under age 20. For the infants of mothers under age 15, the postneonatal death rate was 3 times as high as for those of 20-24 year old mothers. Beginning with age 20, the risk of postneonatal mortality decreases gradually as maternal age increases up to 35 years, when it begins to rise again in the white race. In nonwhite races, the decline continoues to age 40. Infants born to young mothers of nonwhite races suffer relatively higher postneonatal mortality than do their white counterparts. The postneonatal mortality rate is lowest for 1st born infants of both races. Among nonwhites, it is highest for the 2nd born; in the white race, it rises with each successive birth, with the exception of the 5th. Postneonatal mortality among very small white infants (those weighing less thatn 1500 gm at birth) was some 7 times that of infants weighing more than 2500 gm; it was even higher in nonwhite races being nearly 2 1/2 times that of the white group and appoproximately 4 times higher than the rate for nonwhite infants weighing more than 2500 gm at birth. The risk of postneonatal death for nonwhite infants born illegitimately was 1 1/2 times as great for those born in wedlock. Among white infants, the risk was almost twice as great for those born out of wedlock.     

Strategies for reduction of neonatal mortality

Summary  Infant mortality rates in developed countries have shown significant decreases in recent years. Two-thirds of infant mortality still occurs in the neonatal period and our aim in this study was to review the causes of these neonatal deaths and see where further improvements may be possible. A 6-yr review of all neonatal deaths of live-born infants over 500g birthweight from 1991 to 1996 was made. The 1989 amended Wigglesworth classification was used to categorise cause of death and other perinatal variables were also recorded. Results show there were 34,375 births and 153 neonatal deaths. Classification of these deaths by Wigglesworth found 78 (51 per cent) due to congenital malformations, 58 (38 per cent) due to prematurity, 6 (4 per cent) due to asphyxia and 11 (7 per cent) due to specific other causes. The corrected neonatal mortality was 2.18. Neural tube defects alone accounted for 10 per cent of the total neonatal mortality. Fifty-five out of 58 infants who died due to prematurity had birthweight < 1000g and survival rates in this group compared well to international standards. We conclude that a reduction in neonatal mortality is possible but is most likely to result from community focused measures such as increased use of pre- and peri-conceptional folate.     

Care of very low birthweight infants with limited neonatal intensive care resources

The advanced technology that is available to treat the tiniest infants has raised the legal and moral dilemma of where and how to distribute limited intensive care resources. In one neonatal intensive care unit it was determined that approximately 80% of its resources over a two-year period were utilized by very low birthweight infants, in spite of the fact that these infants comprised less than 50% of the total admissions to the unit. It was not possible to offer all very low birthweight infants full intensive care; to make this possible, it was calculated that resources would have to increase by 26%. In the present economic climate, and with limited numbers of nurses who are skilled in neonatal intensive care, the prospects for extra resources are poor. What action can or should be taken, legally and morally, when no facilities exist to treat a live-born infant who may possibly benefit from intensive care?     

Mortality in infants discharged from neonatal intensive care units in Georgia

Although neonatal intensive care units (NICUs) have contributed to advances in neonatal survival, little is known about the epidemiology of deaths that occur after NICU discharge. To determine mortality rates following NICU discharge, we used linked birth, death, and NICU records for infants born to Georgia residents from 1980 through 1982 and who were admitted to NICUs participating in the state's perinatal care network. Infants who died after discharge (n = 120) had a median duration of NICU hospitalization of 20 days (range, 1 to 148 days) and a median birth weight of 1983 g (range, 793 to 5159 g). The postdischarge mortality rate was 22.7 per 1000 NICU discharges. This rate is more than five times the overall postneonatal mortality rate for Georgia from 1980 to 1982. The most common causes of death were congenital heart disease (23%), sudden infant death syndrome (21%), and infection (13%). Demographic characteristics commonly associated with infant mortality were not strongly associated with the mortality following NICU discharge.     

Perinatal outcome and antenatal care in a black South African population.

The relationship between perinatal outcome and antenatal care was investigated at King Edward VIII Hospital, Durban, by a case control retrospective study of pregnancy records in 165 perinatal deaths and 156 infants surviving the perinatal period. 82% of the mothers of live infants had booked for antenatal care compared with only 60% of those who experienced a perinatal death. Hospital booking was associated with a higher infant birthweight. For those who booked earlier there was no reduction in total perinatal mortality or the stillbirth:neonatal death ratio, and many of the mothers of highest risk failed to book. This suggests that the better perinatal outcome in booked mothers may have been secondary to the type of mother who chose to book, rather than the actual antenatal care. To help reduce perinatal mortality, methods must be employed which reach those mothers who are most likely to fail to book.     

The contribution of mild and moderate preterm birth to infant mortality. Fetal and Infant Health Study Group of the Canadian Perinatal Surveillance System

CONTEXT: The World Health Organization defines preterm birth as birth at less than 37 completed gestational weeks, but most studies have focused on very preterm infants (birth at <32 weeks) because of their high risk of mortality and serious morbidity. However, infants born at 32 through 36 weeks are more common and their public health impact has not been well studied. OBJECTIVE: To assess the quantitative contribution of mild (birth at 34-36 gestational weeks) and moderate (birth at 32-33 gestational weeks) preterm birth to infant mortality. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort study using linked singleton live birth-infant death cohort files for US birth cohorts for 1985 and 1995 and Canadian birth cohorts (excluding Ontario) for 1985-1987 and 1992-1994. MAIN OUTCOME MEASURES: Relative risks (RRs) and etiologic fractions (EFs) for overall and cause-specific early neonatal (age 0-6 days), late neonatal (age 7-27 days), postneonatal (age 28-364 days), and total infant death among mild and moderate preterm births vs term births (at >/=37 gestational weeks). RESULTS: Relative risks for infant death from all causes among singletons born at 32 through 33 gestational weeks were 6.6 (95% confidence interval [CI], 6.1-7.0) in the United States in 1995 and 15.2 (95% CI, 13.2-17.5) in Canada in 1992-1994; among singletons born at 34 through 36 gestational weeks, the RRs were 2.9 (95% CI, 2.8-3.0) and 4.5 (95% CI, 4.0-5.0), respectively. Corresponding EFs were 3.2% and 4.8%, respectively, at 32 through 33 gestational weeks and 6.3% and 8.0%, respectively, at 34 through 36 gestational weeks; the sum of the EFs for births at 32 through 33 and 34 through 36 gestational weeks exceeded those for births at 28 through 31 gestational weeks. Substantial RRs were observed overall for the neonatal (eg, for early neonatal deaths, 14.6 and 33.0 for US and Canadian infants, respectively, born at 32-33 gestational weeks; EFs, 3.6% and and 6. 2% for US and Canadian infants, respectively) and postneonatal (RRs, 2.1-3.8 and 3.0-7.0 for US and Canadian infants, respectively, born at 32-36 gestational weeks; EFs, 2.7%-5.8% and 3.0%-7.0% for the same groups, respectively) periods and for death due to asphyxia, infection, sudden infant death syndrome, and external causes. Except for a reduction in the RR and EF for neonatal mortality due to infection, the patterns have changed little since 1985 in either country. CONCLUSIONS: Mild- and moderate-preterm birth infants are at high RR for death during infancy and are responsible for an important fraction of infant deaths. JAMA. 2000;284:843-849     

Hospital costs for cocaine-exposed infants

A retrospective study was done at University Medical Center at Jacksonville for the period November 1988 through October 1989 to estimate the cost of treatment for 207 infants from cocaine-exposed pregnancies, 151 (76%) black and 56 (24%) white. The mean age of the mothers was 26. Twenty-five (12%) infants were admitted into the neonatal intensive care nursery (NICU) and 82 (88%) into the normal nursery where 45% of total days was due to "social hold" pending clearance for discharge by the Florida Department of Health and Rehabilitative Services. Average stay was 21.5 days in the NICU and 6.7 days in the normal nursery. Average costs varied from $36,481 for NICU to $801 for normal nursery in excess of the usual charge for a normal full-term infant. Laboratory fees accounted for the largest percentage (41.5%) of the total cost of hospitalization in the NICU, while rooming charges are the major factor (50.8%) in the normal nursery. Total charges in the 12-month period amounted to $1,057,921 or $5,110 per patient and for a control group $520,251 or $2,513 per patient. A major concern above the cost of treatment is the special education needs when these children enter the school system.     

Costs and benefits of a community special care baby service

Between January 1981 and December 1986 3829 low birthweight (less than 2500 g) infants and 1980 other high risk infants were cared for at home after they were discharged from hospital by a specialist neonatal nursing service. Of the infants who were referred to this service, 720 (12%) weighed under 2000 g and 1919 (33%) under 2250 g at the time of discharge home. The infants were visited by the community neonatal sisters on an average of 11 occasions, but the number of visits varied from six to over 100 depending on the needs of the child and parents. There was close liaison with other community and hospital staff. Two hundred and thirty (4%) referred infants were readmitted to hospital while under the care of the specialist nursing service. In 1985 the cost of the service was pounds 127,000, or pounds 123 for each infant referred. Providing this specialist support at home allowed much earlier discharge of low birthweight infants from hospital. When compared with the cost of providing continuing inpatient neonatal care earlier discharge was estimated to have saved roughly pounds 250,000 in 1985. Low birthweight infants have an increased risk of serious illness or death that extends beyond the neonatal period. Many are born to young and socially disadvantaged parents who can benefit from expert guidance and support at home. A community neonatal nursing service has advantages for high risk infants and their parents, is cost effective, and allows more efficient use of limited hospital resources.     

Infant mortality among Hispanics. A portrait of heterogeneity

In the United States, infant mortality risks among Hispanics have not been previously evaluated at the national level. We used the 1983 and 1984 national Linked Birth and Infant Death data sets to compare infant mortality risks among single-delivery infants of Hispanic descent with those among single-delivery infants of non-Hispanic whites (the reference group). We also included the 1983 and 1984 linked birth cohort for single-delivery infants in Puerto Rico. Among all Hispanic groups, the neonatal (less than 28 days) mortality risk was higher among Puerto Rican islanders (relative risk [RR] = 2.3) and continental Puerto Ricans (RR = 1.5) and lower among Cuban-Americans (RR = 1.0) and Mexican-Americans (RR = 1.0). The postneonatal mortality risk (28 to 364 days) was highest among continental Puerto Ricans (RR = 1.2) and lowest among Cuban-Americans (RR = 0.6). Our study underscores the heterogeneity of the Hispanic population in the United States and suggests that interventions to prevent infant mortality be tailored to ethnic-specific risk factors and outcomes.     

预防保健:围产期妇幼保健中缺失的一环

1 The need to extend and expand the maternal, neonatal and child health (MNCH) continuum to include preconception health The provision of care along the MNCH continuum is currently the core strategy for reducing maternal, neonatal and infant mortality [1-5]. Yet, gaps in the MNCH continuum persist. Reductions in maternal mortality have stagnated in many parts of the world. With the lowering of infant and child mortality, approximately 40% of infant deaths now occur in the neonatal period[6].     

Infant mortality in West Virginia. Identifying risk factors for public health intervention

Because infant death rates vary within populations, it is important for program managers and planners to identify high-risk subgroups for whom effective interventions can be targeted. Matching infant death certificates with birth records permits us to describe infant mortality and calculate risks by a variety of maternal and infant characteristics recorded at birth. In this paper, we illustrate how several variables are associated with infant death, and show how analysis of a recent birth cohort in West Virginia can assist health officials in determining appropriate strategies for risk reduction. While efforts need to focus on reducing social and economic barriers to maternal and infant health, different strategies are required to address separately the neonatal and postneonatal components of infant mortality. Matched records can be used in a variety of ways to develop support for, and highlight the needs of, West Virginia's Maternal and Child Health programs, to monitor trends over time, to evaluate program achievements, and to modify program goals.     

Using scientific evidence to shape research, intervention programs, and policy in a statewide effort to reduce infant mortality, 2004-2009

Based on steadily increasing rates from the mid-1990s through 2005 (e.g., rates reached a high of 9.3 deaths per 1,000 live births in the 2000-2004 time frame), the Delaware infant mortality initiative began in 2004. The initiative consisted of a synthesis of quantitative analyses and state-led programs at all public health agencies as directed from the Governor's Office. Throughout the first four years of implementation, Division of Public Health (DPH) staff utilized vital statistics data to produce a statewide research agenda that included reviewing vital record reporting procedures, highlighting infant mortality disparities by birthweight and race, studying the effect of plural births and other demographic factors on infant deaths, and using data to justify proposed research projects. Results indicated that black infants were dying at twice the rate of white infants (Disparity Ratio: 2.2), and extremely low birth weight infants were the biggest contributing population to infant mortality, specifically births of infants less than 500 grams. Further results indicated that intervention efforts should focus on preconception care for women of reproductive age and prevention of prematurity. These findings led to the implementation of research-based statewide surveillance programs and registries to identify women who experienced poor birth outcomes. Additionally, analyses provided the basis for implementing two major intervention programs, statewide education campaigns, and proposed revision of state standards. This paper illustrates the translation of research findings into practically applicable recommendations for statewide surveillance, programs, and policy development.     

Inconsistencies in coding of race and ethnicity between birth and death in US infants. A new look at infant mortality, 1983 through 1985.

OBJECTIVE--To ascertain the consistency of the racial and ethnic classification of US infants between birth and death and its impact on infant mortality rates. SUBJECTS--All US infants born from 1983 through 1985 who died within a year. DESIGN--We used the national linked birth/infant-death computer tape, augmented with information on infants' race and ethnicity at death, to compare the coding of race and Hispanic ethnicity at birth and at death. We also assessed infant mortality rates by race and ethnicity as defined (1) by the standard algorithm and (2) by the rule that, beginning in published tabulations for 1989, assigns newborns the race of their mothers. Finally, we estimated infant mortality rates based on consistent coding of race and ethnicity at birth and death. RESULTS--Inconsistency in the coding of race is low for whites (1.2%), greater for blacks (4.3%), and greatest for races other than white or black (43.2%). Most infants reclassified at death (87.3%) are classified as white at death. Inconsistency in coding is lower for non-Hispanic whites (3.5%) and non-Hispanic blacks (3.3%) than for Hispanic populations (30.3%). Compared with the standard algorithm for calculation of infant mortality, consistent definition at birth and death produces rates 2.1% lower for whites, and higher for all other groups--3.2% for blacks, 46.9% for American Indians, 33.3% for Chinese, 48.8% for Japanese, 78.7% for Filipinos, and 8.9% for Hispanics. CONCLUSIONS--The coding of race and ethnicity of infants at birth and death is remarkably inconsistent, with substantial impact on the estimation of infant mortality rates. A need exists to reconsider the nature and definition of race and ethnicity in public health.     

低出生体重儿死亡率与脑性瘫痪患病率的研究

目的 评估低出生体重儿新生儿期死亡和脑瘫患病风险。方法 利用安徽省两个城市1995～1999年围生儿登记资料和围生期死亡监测记录，结合脑瘫的现患调查，分析低出生体重儿新生儿期死亡情况以及脑瘫患病率。结果 低出生体重儿脑瘫占所有脑瘫病例的28．9％。在低出生体重儿中，随出生体重的下降，早期新生儿死亡率和新生儿死亡率上升；出生体重为2000～2499g、l500～l999g以及l500g以下的活产儿脑瘫患病率分别为9．29‰、18．87‰和30．30‰，与出生体重3500～3999g新生儿相比，3组低出生体重儿脑瘫患病的OR值分别为13．9、28．5和46．3。结论 低出生体重儿存活率低于发达国家，但脑瘫患病率与发达国家接近。随着极低出生体重儿存活率的上升，儿童脑瘫患病率可能会上升。     

Neonatal sepsis in very low birthweight infants at the University Hospital of the West indies

A retrospective review was conducted on the charts of all very low birthweight (VLBW) infants with culture proven sepsis admitted to the neonatal unit of the University Hospital of the West Indies (UHWI) during the period January 1, 1995 to December 31, 2000. During the study period, 22 VLBW infants were admitted to the neonatal unit with culture proven sepsis, 16 (73%) survived and 6 (27%) died As birthweight and gestational age increased, outcome improved There was no difference in survival based on age at presentation. Neonates with early onset disease had a significantly longer mean duration of rupture of membranes than those with late onset disease (p = 0.009) and babies with late onset disease had a significantly lower mean Hb level than those with early onset disease (p = 0.000). Predominant isolates were Klebsiella sp (10, 37%), Streptococcus Group D (4, 15%), Escherichia coli (3, 11%) and Group B Streptococcus (3, 11%). Klebsiella sp accounted for 8/13 (62%) of late onset infections. Complications included anaemia, thrombocytopenia, bleeding and multi-organ failure. Strategies aimed at prevention, such as limiting the excessive use of broad-spectrum empiric antibiotics and the periodic review and continuous reinforcement of infection control policies will help decrease the mortality and morbidity associated with nosocomial infection in the VLBW infant.     

Babies born under 1000 g--perinatal outcome.

Improved survival of very pre-term infants is a result of advances in obstetric and neonatal medicine. To provide relevant data for a Northern Ireland population group, we evaluated mortality and morbidity of extremely low birthweight (ELBW; < 1000 g) infants from a tertiary referral neonatal unit. Seventy-seven ELBW infants were admitted on the first day of life during the period April 1990 to April 1992. Mean (SD) gestational age (GA) was 26.2 (2.1) weeks and birthweight (BW) was 781 (132) g. The degree of severity of initial illness was high, with a mean (SD) CRIB (clinical risk index for babies) score of 7.4 (4.2). Fifty (65%) babies survived, being discharged home at a mean (SD) age of 95 (34) days. Survivors were more likely to have received maternal steroid therapy or been born in this hospital. Ten (20%) of the survivors had evidence of severe neonatal brain injury or cranial ultrasonography--Papile grade 3 or 4 intraventricular haemorrhage (IVH) or periventricular leucomalacia (PVL). Survival rate of ELBW infants without severe brain injury was 54% overall; this ranged from 0% in ELBW infants born at 23 weeks GA and 33% at 24 weeks GA to 85% at 27 weeks GA.     

Altitude, low birth weight, and infant mortality in Colorado

A decrease in birth weight occurs at high altitude, but its relationship to infant mortality is unclear. We examined Colorado vital statistics recorded from 1979 through 1982 to determine whether high altitude increased infant mortality and whether decreased birth weight contributed to the mortality observed. Retardation of intrauterine growth reduced birth weight and doubled the frequency of low-birth-weight infants from the lowest (915 to 1523 m [3000 to 4999 ft]) to the highest (greater than or equal to 2744 m [greater than or equal to 9000 ft]) altitude in the state. Low birth weight increased mortality risk, but the mortality risk of low birth weight was decreased at high compared with low altitudes, resulting in similar infant mortality rates throughout the state. This finding differed from that of 1969 through 1973 when infant mortality doubled at high altitude. A 46% infant mortality reduction had occurred statewide over the ten years due chiefly to decreased mortality risk for preterm low-birth-weight infants. This reduction, particularly pronounced at high altitude, might have been due to better identification and transport of high-risk pregnancies to hospitals with tertiary neonatal treatment centers.