The nasopharyngeal bacterial flora in infancy: effects of age, gender, season, viral upper respiratory tract infection and sleeping position

The aim of the investigation was to determine the effect of age, gender, viral upper respiratory tract infection (URTI), season and sleeping position on the composition of the nasopharyngeal bacterial flora in infancy. Seventy-two babies, 38 male and 34 female, whose birthdates were evenly spread throughout the year were followed from birth to 18 months of age. From 0 to 6 months nasopharyngeal swabs were obtained once a month in periods without URTI and daily for 3 days during episodes of URTI. From 12 to 18 months of age nasopharyngeal swabs were obtained in the early morning alter an overnight sleep and later in the day after the baby had been up for over 2 h. Swabs were obtained in prone and supine sleepers with and without infection. In infants aged 0-6 months URTI had little effect on the nasopharyngeal bacterial flora, but there was a marked effect of age and less marked effect of season and gender. In particular Staphylococcus aureus carriage decreased with age, was most common in the winter months and the density of colonisation was greater in males than females. In infants aged 12-18 months the combination of prone sleeping with URTI and an early morning swab led to increased carriage of staphylococci, streptococci. Haemophilus influenzae and Gram-negative bacilli which are not normally part of the nasopharyngeal flora. These results are relevant to sudden infant death syndrome (SIDS). The combination of prone sleeping and URTI reproduces the nasopharyngeal flora seen in SIDS. Gram-negative bacilli isolated from SIDS cases should not be dismissed as post-mortem contaminants. The features of S. aureus make it a prime candidate for a pathogenic role in SIDS.     

Postmortem Human Brain pH and Lactate in Sudden Infant Death Syndrome

Lactate and pH were measured in frontal and temporal cortex, cingulate gyrus, and caudate nucleus in brains from sudden infant death syndrome (SIDS) cases, control infants, and control adults. Both the lactate levels and the pH values were significantly correlated (p less than 0.001) between the four brain areas, whereas lactate and pH values were significantly correlated within each brain area (p less than 0.001) with a value of pH 7.2 for zero lactate. The lactate concentration in heart blood was significantly correlated with brain lactate (p less than 0.001). Adult sudden death cases (heart attacks) had low lactate and high pH values, whereas agonal state cases had high lactate and low pH values. Control infants who had died because of accidents also had low lactate and high pH values, but infants who might have been exposed to hypoxia before death had high lactate and low pH values. SIDS cases fell into two groups: the first, consisting of all victims over 30 weeks of age and about one-half to two-thirds of those aged less than 30 weeks, had low lactate and high pH values; the second group, consisting of about one-third to one-half of those less than 30 weeks old, had high lactate and low pH values. The changes in lactate levels and pH values indicate that the majority of SIDS cases had died suddenly, but that a sizeable minority had been exposed to hypoxia prior to death.     

Cigarette smoking as risk factor for late fetal and early neonatal death.

Risk factors for late fetal death and early neonatal mortality were examined in a population based prospective study. Practically all Swedish births between 1983 and 1985 were included, 281,808 births in all. The overall rates of late fetal death and early neonatal mortality were 3.5 and 3.1 per 1000, respectively. About 30% of the pregnant women were recorded as being daily smokers. Logistic regression analyses showed significant relative risks for late fetal death for high maternal age (1.4), nulliparity (1.4), multiparity (greater than or equal to 2) (1.3), smoking (1.4), and multiple births (2.8). Significant relative risks for early neonatal mortality were found for multiple births (4.9) and smoking (1.2). Smokers aged under 35 faced a relative risk of late fetal death ranging from 1.1 to 1.6, while the risk for late fetal death was doubled if the mothers were aged 35 years or more and smoked. In countries like Sweden, where maternal cigarette smoking is prevalent, smoking may be the most important preventable risk factor for late fetal death.     

Contribution of preterm delivery to perinatal mortality.

A detailed retrospective analysis was made of the records of 486 preterm infants, who accounted for 5-1% of all births during 1973 and 1974. Whereas preterm delivery did not contribute to perinatal mortality in terms of stillbirth, it outweighed all other causes in terms of early neonatal deaths. Preterm birth was responsible for 85% of the early neonatal deaths not due to lethal congenital deformities. Early neonatal mortality rates were closely linked both to gestational age and birth weight and to the reason for preterm birth. Early neonatal mortality was high (97 per 1000) when preterm labour was spontaneous, whether or not associated with material or fetal disease or with multiple pregnancy, but low (27 per 1000) when preterm delivery was elective. Preventing spontaneous preterm labour would considerably reduce neonatal mortality in our community.     

Variation in early neonatal mortality for different types of fetal growth retardation

Birth and first-48-hr death records were analyzed for 10,024 liveborn infants in Mexico City and 12,786 liveborn infants in Santa Cruz, Bolivia. The objective of the analysis was to characterize the early postnatal mortality rates for different types of fetal growth retardation and prematurity. Infants who were delivered prior to 37 weeks of gestation had 23-100 times the mortality risk of infants born at full term and normal weight. Light-for-gestational-age infants (birth weight less than 2,900 g) were further divided into proportionately growth-retarded with normal Rohrer's index (weight/height) and disproportionately growth-retarded with low Rohrer's index. The proportionately growth-retarded infant had nearly twice the mortality of the full-term, appropriate-weight infants, whereas the disproportionately growth-retarded infants had 2.9-5.7 times the mortality rate of the full-term, appropriate-weight infants. There were some differences between samples in mortality rates and prevalence of the different classes of small infants, but the pattern of mortality within samples was consistent between samples.     

Measures of early postoperative mortality: beyond hospital fatality rates.

OBJECTIVE--To quantify the short term risk of postoperative mortality in ways which take account of deaths after discharge and the background risks of death in patients who come to operation. DESIGN--Analysis of linked abstracts of hospital admission records and death certificates for common operations. SETTING--Six health districts in the Oxford region. SUBJECTS--Records of 223,529 operations performed in 1980-6. MAIN OUTCOME MEASURES--In hospital fatality rates, case fatality rates, and standardised mortality ratios at selected time periods during the year after operation and the ratio of early (< 30 days) to late (90-364 days after operation) fatality rates. RESULTS--Fatality rates throughout the year after operations performed after emergency admissions were generally higher than those for similar operations performed after elective admissions and higher than expected from population rates. Examples were prostatectomy, hip arthroplasty, inguinal herniorrhaphy, and cholecystectomy. Common elective operations such as inguinal herniorrhaphy and cataract operations showed no early peak in mortality, but others did. These included transurethral prostatectomy (ratio of early to late mortality 2.0; 95% confidence interval 1.3 to 2.6), hysterectomy (3.2; 1.5 to 6.6), hip arthroplasty (3.8; 2.5 to 5.4), and cholecystectomy (6.9; 4.3 to 11.1). CONCLUSIONS--Temporal profiles of death rates in the year after operation show which operations have early peaks in mortality and which do not. Emergency and elective operations have very different profiles and should be analysed separately. For elective operations for conditions which pose no immediate threat to life the ratio of early to later fatality rates provides a measure of increase in mortality after operation while allowing for the background risk of death in the patient groups.     

Sudden infant death syndrome and postneonatal mortality in immigrants in England and Wales.

To examine ethnic differences in postneonatal mortality and the incidence of sudden infant death in England and Wales during 1982-5 records were analysed, the mother''s country of birth being used to determine ethnic group. Postneonatal mortality was highest in infants of mothers born in Pakistan (6.4/1000 live births) followed by infants of mothers born in the Caribbean (4.5) and the United Kingdom and Republic of Ireland (4.1). Crude rates were lower in infants of mothers born in India (3.9/1000), east and west Africa (3.0), and Bangladesh (2.8) than in infants of mothers born in the United Kingdom despite less favourable birth weights. Mortality ratios standardised separately for maternal age, parity, and social class were significantly higher in infants of mothers born in Pakistan and lower in those of mothers born in Bangladesh. The ratio for infants of Caribbean mothers was significantly higher when adjusted for maternal age. Ratios for infants of Indian and east African mothers did not show significant differences after standardisation. An important finding was a low incidence of sudden infant death in infants of Asian origin. This was paralleled by lower mortality from respiratory causes. During 1975-85 postneonatal mortality in all immigrant groups except Pakistanis fell to a similar or lower rate than that in the United Kingdom group; Pakistanis showed a persistent excess. During 1984-5 several immigrant groups (from the Republic of Ireland, India, west Africa, and the Caribbean) recorded an increase in postneonatal mortality. Surveillance of postneonatal mortality among ethnic communities should be continued, and research is needed to identify the causes underlying the differences.     

Change in immunisation schedule and sudden infant death syndrome in Hungary

Infant mortality in Hungary was higher than in other European countries; however, the reported incidence of sudden infant death syndrome (SIDS) has been lower than those for Western Europe and the United States. Childhood immunisation has been reported to be a protective factor for SIDS. In Britain, the change to an earlier immunisation schedule for diphtheria, pertussis, and tetanus appeared to be associated with a shift in the age distribution of SIDS. In 1999, immunisation for Haemophilus influenzae type b (Hib) was introduced for Hungarian infants at the age of 2 months. Data for total infant mortality and SIDS in Hungary were analysed between 1990 and 2002. Infection was the major cause of death among Hungarian infants followed by SIDS. Following introduction of Hib immunisation, there was a decrease in deaths due to meningitis from an average of 3.5% of all infant deaths between 1990 and 1998 to an average of 1% of all infant deaths between 1999 and 2002 (p=0.00). There was also a significant decrease in the proportion of SIDS in the age range > or =2 months from 48% in the earlier period to 39% after introduction of the vaccine (p=0.03). The decrease in SIDS might be due in part to decrease in unrecognised Hib infections or to induction of antibodies by the tetanus toxoid to which the Hib polysaccharide is conjugated that are cross reactive with bacterial toxins implicated in SIDS.     

Circadian variation of the frequency of sudden infant death syndrome and of sudden death from life-threatening conditions in infants

136 infants died of sudden infant death syndrome (SIDS) and 140 infants died suddenly and unexpectedly from life-threatening conditions (LTC) from 1983 to 1989 in Leningrad entered the study. 24-hour distribution of death cases was evaluated in both studied groups. The increased incidence of SIDS was revealed from 04(00) to 06(00). There was not significant difference between circadian variation of SIDS and that of death from LTC. The early morning seems to be the time when the risk factors that lead to sudden death are likely to be prominent.     

Contribution of twin pregnancy to perinatal mortality and fetal growth retardation; reversal of growth retardation after birth.

A survey of factors associated with perinatal mortality in 511 twins and fetal growth retardation and its reversal in 262 twins is presented. The incidence of stillbirth was almost 50% higher in twins than in singletons and the neonatal mortality was six times as high. Eighty percent of the neonatal deaths occurred in infants born prior to or at 30 weeks of gestation; 93% of the deaths were in infants weighing less than 1500 g and 75% occurred within 48 hours of birth. Fetal malnutrition was the main cause of stillbirth, and respiratory distress syndrome and asphyxia neonatorum were the main causes of neonatal death. One quarter of the twins had fetal growth retardation, a prevalence 10 times that in singletons. In almost all, the growth retardation was reversed by high-energy feedings. Although twins represented only 1% of all pregnancies and 2% of live births, they composed 12% of infants with early neonatal death and 17% of growth-retarded infants. A program is suggested for reduction of twin mortality and morbidity.     

Canine perinatal mortality: a cohort study of 224 breeds

Canine perinatal mortality is known to be relatively high. However, the literature on perinatal mortality in dogs is still sparse and often refers to a single or only a few breeds. The aim of this large-scale observational study was to describe the perinatal mortality in purebred dogs of various breeds at both puppy and litter level. In addition, the influence of breed, breed size, litter size, age of the bitch, litter number and season for whelping on the risk of perinatal mortality at litter level was studied and the mean litter size at eight days and eight wks after birth was calculated. A retrospective cohort study was performed by studying 10,810 litters of 224 breeds registered in the Norwegian Kennel Club in 2006 and 2007. Perinatal mortality was defined as the sum of stillborn puppies and puppies that died during the first wk after birth (early neonatal mortality) and was present in 24.6% of the litters. Eight percent of the puppies died before eight days after birth, with 4.3% as stillbirth and 3.7% as early neonatal mortality. For most breeds the perinatal mortality was low, but for some breeds a higher perinatal mortality was found. The mean litter size at eight days and eight wks after birth was 4.97 (±0.02) and 4.92 (±0.02) puppies, respectively. Of all puppies born, only 1% died during the period from eight days to eight wks after birth. Random effects logistic regression analysis indicated that increasing litter size and age of the bitch were associated with an increased risk of stillbirth, early neonatal mortality and total perinatal mortality at the litter level (P < 0.001). The random breed effect was significant for all outcomes. Litter number also had a significant effect on stillbirth, early neonatal mortality and total perinatal mortality at the litter level, with the highest risk of perinatal mortality found in the first litter (P < 0.001). Further, the risk of early neonatal mortality was doubled in litters with stillborn puppies. No significant effect of whelping season on perinatal mortality at litter level was found. An interaction existed between the age of the bitch and litter number and the risk of stillbirth was three times as high (odds ratio = 3.00) in litters from bitches having their first litter after the age of six y. Breed was a more important determinant of perinatal mortality in litters than breed size. However, more than 90% of the variation in perinatal mortality was found at the individual litter level and efforts to minimize puppy mortality should be targeted at the management of the individual litter rather than at the breed level.     

Evidence for infection, inflammation and shock in sudden infant death: parallels between a neonatal rat model of sudden death and infants who died of sudden infant death syndrome

This study compared pathological findings from a neonatal rat model of sudden death with those from 40 sudden infant death syndrome (SIDS) infants collected at autopsy. In the rat model, influenza A virus was administered intranasally on postnatal day 10, and on day 12 a sublethal, intraperitoneal dose of Escherichia coli endotoxin; mortality was 80%. Tissue samples from the animals and infants were fixed in formaldehyde, embedded in paraffin, and sections stained with hematoxylin and eosin. Tissues from the SIDS specimens were additionally cultured for bacteria and viruses; post-mortem blood samples were evaluated for signs of inflammation. All sections were examined by a pediatric forensic pathologist familiar with SIDS pathology. Comparisons between the rat model and the human SIDS cases revealed that both exhibited gross and microscopic pathology related to organ shock, possibly associated with the presence of endotoxin. Uncompensated shock appeared to be a likely factor that caused death in both infants and rat pups. Response to a shock-inducing event might have played an important role in the events leading to death. The similarities between the neonatal rats and the human cases indicate that further research with the model might elucidate additional aspects of SIDS pathology.     

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.     

Sudden infant death syndrome and Canadian Aboriginals: bacteria and infections

Aboriginal populations in Canada, America and Australia have higher incidences of sudden infant death syndrome (SIDS) than non-Aboriginal groups. Canadian Aboriginal populations (known also as first nation, native or Indian) experience infant morbidity/mortality rates 3-7 times that of non-Aboriginals, with upper track respiratory infection and SIDS recorded as the leading causes. The aim of this investigation was to examine the home environment of Aboriginal infants, particularly during winter months when respiratory tract infections and SIDS are more common. Environmental bacteria, fungi and air particulates were examined in the residences of Aboriginal infants during visits to individual homes on an Aboriginal reserve. The physical histories of SIDS victims were gathered from medical files. Air and surfaces were sampled by agar strips which were processed by a commercial laboratory. The levels of fungi, bacteria and air particulate rates recorded in the reserve homes of Aboriginal infants registered levels considered to be detrimental to the health of the inhabitants. Such extreme levels could contribute to the high incidence of respiratory disease and SIDS experienced by Canadian Aboriginal infants.     

Gestational age patterns of fetal and neonatal mortality in Europe: results from the Euro-Peristat project

Background

The first European Perinatal Health Report showed wide variability between European countries in fetal (2.6–9.1‰) and neonatal (1.6–5.7‰) mortality rates in 2004. We investigated gestational age patterns of fetal and neonatal mortality to improve our understanding of the differences between countries with low and high mortality.

Methodology/Principal Findings

Data on 29 countries/regions participating in the Euro-Peristat project were analyzed. Most European countries had no limits for the registration of live births, but substantial variations in limits for registration of stillbirths before 28 weeks of gestation existed. Country rankings changed markedly after excluding deaths most likely to be affected by registration differences (22–23 weeks for neonatal mortality and 22–27 weeks for fetal mortality). Countries with high fetal mortality ≥28 weeks had on average higher proportions of fetal deaths at and near term (≥37 weeks), while proportions of fetal deaths at earlier gestational ages (28–31 and 32–36 weeks) were higher in low fetal mortality countries. Countries with high neonatal mortality rates ≥24 weeks, all new member states of the European Union, had high gestational age-specific neonatal mortality rates for all gestational-age subgroups; they also had high fetal mortality, as well as high early and late neonatal mortality. In contrast, other countries with similar levels of neonatal mortality had varying levels of fetal mortality, and among these countries early and late neonatal mortality were negatively correlated.

Conclusions

For valid European comparisons, all countries should register births and deaths from at least 22 weeks of gestation and should be able to distinguish late terminations of pregnancy from stillbirths. After excluding deaths most likely to be influenced by existing registration differences, important variations in both levels and patterns of fetal and neonatal mortality rates were found. These disparities raise questions for future research about the effectiveness of medical policies and care in European countries.     

Time trends and demography of mortality after fractured neck of femur in an English population, 1968-98: database study

Objectives To investigate time trends in mortality after admission to hospital for fractured neck of femur from 1968 to 1998, and to report on the effects of demographic factors on mortality.Design Analysis of hospital inpatient statistics for fractured neck of femur, incorporating linkage to death certificates.Setting Four counties in southern England.Subjects 32 590 people aged 65 years or over admitted to hospital with fractured neck of femur between 1968 and 1998.Main outcome measures Case fatality rates at 30, 90, and 365 days after admission, and standardised mortality ratios at monthly intervals up to one year after admission.Results Case fatality rates declined between the 1960s and the early 1980s, but there was no appreciable fall thereafter. They increased sharply with increasing age: for example, fatality rates at 30 days in 1984-98 increased from 4% in men aged 64-69 years to 31% in those aged ≥ 90. They were higher in men than women, and in social classes IV and V than in classes I and II. In the first month after fracture, standardised mortality ratios in women were 16 times higher, and those in men 12 times higher, than mortality in the same age group in the general population.Conclusions The high mortality rates, and the fact that they have not fallen over the past 20 years, reinforce the need for measures to prevent osteoporosis and falls and their consequences in elderly people. Whether post-fracture mortality has fallen to an irreducible minimum, or whether further decline is possible, is unclear.     

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.     

Sleeping position in infants over 6 months of age: implications for theories of sudden infant death syndrome

The aim of this study was to determine the prevalence of prone and supine sleeping in infants aged 0-12 months and relate this to changes in the number of cases of sudden infant death syndrome (SIDS) since 1985. Seventy-two babies, 38 male and 34 female, were followed for the first 18 months of life with regular home visits and sleeping position was recorded. In addition, data on the number of cases of SIDS in England and Wales between 1985 and 1995 were analysed. All babies slept supine for the first 5 months of life, but once they could turn over in their cots (mean age 7.34 months, range 5-11 months) the majority slept prone. By 11 months of age, 53 regularly slept prone (73%), 95% CI +/- 19.8%), while 11 slept supine, three adopted the side position and five varied from night to night. The number of cases of SIDS in infants aged 7-11 months has fallen significantly (P<0.0001) in a period in which the prevalence of prone sleeping, in that age group, has not changed. The most plausible explanation for this paradoxical result is that supine sleeping in the first 5 months of life reduces the absolute risk of SIDS in the second 6 months of life even though most babies are then sleeping prone. It is suggested that reduced exposure to nasopharyngeal bacterial superantigens in babies sleeping prone might explain this effect.     

Mortality, Neonatal Morbidity and Two Year Follow-Up of Extremely Preterm Infants Born in the Netherlands in 2007

Background

Extremely preterm infants are at high risk of neonatal mortality and adverse outcome. Survival rates are slowly improving, but increased survival may come at the expense of more handicaps.

Methodology/Principal Findings

Prospective population-based cohort study of all infants born at 23 to 27 weeks of gestation in the Netherlands in 2007. 276 of 345 (80%) infants were born alive. Early neonatal death occurred in 96 (34.8%) live born infants, including 61 cases of delivery room death. 29 (10.5%) infants died during the late neonatal period. Survival rates for live born infants at 23, 24, 25 and 26 weeks of gestation were 0%, 6.7%, 57.9% and 71% respectively. 43.1% of 144 surviving infants developed severe neonatal morbidity (retinopathy of prematurity grade ≥3, bronchopulmonary dysplasia and/or severe brain injury). At two years of age 70.6% of the children had no disability, 17.6% was mild disabled and 11.8% had a moderate-to-severe disability. Severe brain injury (p = 0.028), retinopathy of prematurity grade ≥3 (p = 0.024), low gestational age (p = 0.019) and non-Dutch nationality of the mother (p = 0.004) increased the risk of disability.

Conclusions/Significance

52% of extremely preterm infants born in the Netherlands in 2007 survived. Surviving infants had less severe neonatal morbidity compared to previous studies. At two years of age less than 30% of the infants were disabled. Disability was associated with gestational age and neonatal morbidity.     

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.