Prognosis for infants weighing 1000 g or less at birth

Improvement in mortality of very low birthweight infants and the changing pattern of neonatal mortality: the 50-year experience of one perinatal centre

AIM

Neonatology is a relatively new sub-specialty so we aimed to review survival data in the context of advances in neonatal care.

METHOD

Review of neonatal survival for very low birthweight babies over the last 50 years.

RESULTS

In the data collected from a single tertiary neonatal unit, survival for babies 501-1000 g improved from below 10% in 1959 to over 60% in 2009. Similarly, survival for babies 1001 to 1500 g has improved from approximately 50% to over 90%. During the study period, death due to extreme prematurity or cardiorespiratory problems, namely respiratory distress syndrome, fell from 90% in 1964 to only 45% of neonatal deaths in 2008.

CONCLUSION

In addition to reporting the remarkable improvement in neonatal survival over this period, we have highlighted items of historical context.

Historical notes on immaturity. Part 1: measures of viability

The interest in the limit of viability originated from various sources, including legal requirements, the rejection of mechnical life support, competition for resources, concerns about handicaps, and proximity to the fetus with its limited rights. Gestational age was determined from menstrual history by Hippocratic writers, who established the tenacious idea that 7-, but not 8-month infants could survive. Naegele's rule, already published by Boerhaave in 1744, was correct when applied to the last day of menstruation. Birth weight and length were not measured until the end of the 18(th) century. This remarkable disinterest resulted from superstition, grossly inaccurate measurements by the authorities Mauriceau and Smellie, and the conversion chaos of the pre-metric era. A table is provided with historic mass and length units allowing to determine birth weight and body length in the older literature. The idea of viability is a remnant of vitalism, a medical doctrine popularized in 1780 by Brown. Many short-lived statements defined its limit, but until now what was meant by viability remained nebulous.

Impact of cesarean section on neonatal mortality rates among very preterm infants in the United States, 2000-2003

OBJECTIVE

The objective of this analysis was to compare the neonatal mortality rates for infants delivered through primary cesarean section versus vaginal delivery, taking into consideration a number of potentially risk-modifying conditions.

METHODS

US linked birth and infant death certificate files for 2000-2003 were used. Demographic, medical, and labor and delivery complications were abstracted from the files with infant information. The primary outcome examined was neonatal death (death at 0-27 days of age). Because of concern regarding misclassification of gestational age, a procedure was used to trim away births for which the birth weight for a specific gestational age was incongruous. Adjusted odds ratios were calculated for the risk of neonatal death relative to the mode of delivery (primary cesarean section versus vaginal delivery), using logistic regression analysis.

RESULTS

There were data for 13,733 neonatal deaths and 106,809 survivors available from the trimmed data set for analysis for the 4-year period. More than 80% of pregnancies with delivery between 22 and 31 weeks of gestation experienced >or=1 risk factor. Adjusted odds ratios demonstrated significantly reduced risk of neonatal death for infants delivered through cesarean section at 22 to 25 weeks of gestation (adjusted odds ratios of 0.58, 0.52, 0.72, and 0.81 for 22, 23, 24, and 25 weeks, respectively).

CONCLUSION

Cesarean section does seem to provide survival advantages for the most immature infants delivered at 22 to 25 weeks of gestation, independent of maternal risk factors for cesarean section.

Cesarean section and the outcome of very preterm and very low-birthweight infants

Births of extremely preterm infants, less than 26 weeks' gestation, by cesarean section have increased significantly in the United States over the past decade. The justification for this increase is not well supported in the literature. This review examines recent analyses that suggest there may be some survival advantage for infants less than 26 weeks delivered by cesarean section. The appropriateness of intervening with cesarean sections for these very immature infants, however, remains uncertain.

Application of cost-benefit analysis to programmes for the prevention of mental handicap

The paper is a discussion of the role of cost-benefit analysis in evaluating programmes for preventing mental handicap. It is divided into three broad sections. In the first section the technique of cost-benefit analysis is defined and the possible variants considered. It is concluded that policies for the prevention of mental handicap are most appropriately analysed using a mixture of monetary and non-monetary measures of outcome. The second section lays down some guidelines for undertaking a study: the importance of specifying alternatives to the policy being analysed; specifying input-output relationships; counting only the appropriate costs and benefits; and discounting costs and benefits which occur in the future. The third section looks at the current state of the art in the UK. It concludes that little cost-benefit analysis has been done in the field of mental handicap, indicates where work could usefully be directed, and highlights information that would have to be available before a cost-benefit study could give useful results.

Outcome for infants at high risk of major handicap

Perinatal intensive care had been introduced in University College Hospital, London, by 1966. In the succeeding 10 years, 28-day mortality rates fell among infants of birth weight 1500 g or less. Among the survivors, the incidence of major handicap was 10% or less and the mean IQ increased to within the range expected for a normal population. Of the children aged 8 years or more 76% had no handicaps and were attending normal schools; 18% had minor handicaps or problems for which they were receiving extra help in normal schools; and only 6% were attending special schools. Throughout the 10 years of the study, the overall prognosis for these infants of very low birth weight improved significantly. Results among other high-risk groups were equally encouraging. Analysis of variance of the data from the infants who weighed 1500 g or less at birth indicated that perinatal complications, particularly illnesses associated with abnormal neurological signs or acidaemia in the infants around the time of birth, were the principal factors determining the condition of the survivors at follow-up. Thus, it is likely that additional refinements in the management of the perinatal period may result in further improvements in the prognosis of these and other high-risk newborns.

Perinatality: French cost-benefit studies and decisions on handicap and prevention

The Perinatal Care Programme (or 'Périnatalité') was implemented between 1970 and 1975 by the French Ministry of Health, with the aim of reducing the number of birth-related accidents, i.e. the number of deaths and injuries occurring during the perinatal period. It aimed to reduce the perinatal mortality rate from 26/10(3) in 1970 to 18/10(3) in 1980. To give an order of priorities to the actions, a cost-effectiveness evaluation was made. The ratio (Cost over 15 years)/(Number of deaths + number of handicap cases avoided during the same period) indicated that first place should go to resuscitation in the labour room, which cost only 200 francs to save a life while avoiding after-effects. The other measures concerned the training of medical personnel, the development of statistics and research, inoculation against German measles, intensification of antenatal supervision, improvement of supervision during confinement, and the creation of intensive resuscitation units. Evaluation of the programme is still going on. The perinatal mortality rate has considerably decreased, with the objective foreseen for 1980 already reached in 1975. The handicaps will be traced through the results of obligatory screenings at birth, nine months and two years.

Neonatal intensive care and the prevention of major handicap

During the past 20 years there has been a great increase in the understanding of deranged physiological mechanisms in certain groups of newborn infants that were, in the past, at high risk for death or major handicap. Much information of direct clinical relevance has come from the study of experimental animals, particularly about the changes that occur in the lungs and circulation at birth. Work in progress on an animal model of intraventricular haemorrhage suggests that this, like many other causes of brain damage, is a potentially preventable condition. Technological advances, such as continuous blood-gas analysis, make the prevention of handicapping conditions simpler, but the application of modern methods can be expensive. Current evidence shows that neonatal intensive care saves lives, and that the incidence of major handicap in the survivors is reduced. Society will have to decide how much money should be put into this area of medicine, and it will also have to help neonatal paediatricians with the difficult ethical dilemmas that they are now having to face.

Epidemiology of nosocomial infections in selected neonatal intensive care units in Colombia, South America

OBJECTIVE

The epidemiology of nosocomial infections (NI) in neonatal intensive care units in developing countries has been poorly studied. We conducted a prospective study in selected neonatal units in Colombia, SA, to describe the incidence rate, causative organisms, and interinstitutional differences.

STUDY DESIGN

Data were collected prospectively from February 20 to August 30, 2001 from eight neonatal units. NI was defined as culture-proven infection diagnosed after 72 h of hospitalization, resulting in treatment with antibiotics for >3 days. Linear regression models were used to describe associations between institutional variables and NI rates.

RESULTS

A total of 1504 infants were hospitalized for more than 72 h, and therefore, at risk for NI. Of all, 127 infections were reported among 80 patients (5.3%). The incidence density rate was 6.2 per 1000 patient-days. Bloodstream infections accounted for 78% of NIs. Gram-negative organisms predominated over gram-positive organisms (55 vs 38%) and were prevalent in infants < or =2000 g (54%). The most common pathogens were Staphylococcus epidermidis (26%) and Klebsiella pneumonia (12%).

CONCLUSION

Gram-negative organisms predominate in Colombia among infants <2000 g. The emergence of gram-negative organisms and their associated risk factors requires further study.

Biology versus environment in the extremely low-birth weight infant

This article examines the role of biologic and environmental factors in determining the long-term outcomes of extremely low-birth weight infants. Research focusing on follow-up to at least 4 years of age is reviewed. Methodologic issues related to sampling, the use of control groups, and diagnostic criteria are also discussed. The use of cumulative models of risk for examining the relative contribution of environmental and biologic factors is presented.

The effects of neonatal jaundice and respiratory complications on learning and habituation in 5- to 11-month-old infants

The influences of neonatal hyperbilirubinemia and respiratory complications were examined in 5- to 11-month-old infants in two studies. One study focused on habituation performance and the other on contingency learning. In both experiments, three neonatal jaundice conditions (no jaundice history, measured bilirubin, phototherapy) were crossed with two levels of neonatal respiratory risk (no oxygen intervention, oxygen intervention). For low respiratory risk subjects there were increasingly adverse effects for both habituation and learning the more severe the jaundice history. A complex pattern emerged for the high respiratory risk groups. Only for the learning task were the results consistent with a summative effect of neonatal jaundice and respiratory risk factors.

Outcome of infants born preterm, with special emphasis on extremely low birthweight infants

The outcome of extremely low birthweight (ELBW) infants has been reviewed from published articles and up-to-date data from Japan. The mortality rate of these infants declined significantly from over 90% to below 50% after the introduction of intensive care in the 1970s, but the incidence of major neurological sequelae remained steady at around 20%. Similarly, the incidence of major neurological sequelae did not increase along with the decrement of birthweight, although the mortality rate increased significantly. Long-term follow-up of ELBW children until school age has revealed poor school performance in spite of the absence of major neurological sequelae and the attainment of average intelligence quotient scores. Physical growth is retarded initially but generally catches up by the age of 8-9 years. In Japan, the neonatal mortality rate of ELBW infants declined from 56% in 1981 to 25% in 1989 with an increased birth rate of ELBW infants. In ELBW infants cared for at Tokyo Women's Medical College during 1984-90, the survival rate was 112 out of 134 (84%) and the incidence of major neurological sequelae was 15 out of 87 (17%) at 1-8 years old. The viability limit of ELBW infants has been discussed based on recent data. As a result of the rapid progress of medical care of ELBW infants, their viability limit as defined in the Eugenic Protection Law in Japan was amended from 24 completed weeks of gestation to 22 completed weeks in 1991.

Evaluation of care for the preterm infant: review of literature on follow-up of preterm and low birthweight infants. Report from the collaborative Project on Preterm and Small for Gestational Age Infants (POPS) in The Netherlands

Since the introduction of neonatal intensive care in the 1960s, mortality in very preterm and very low birthweight infants has been decreasing steadily. Consequently, interest in the outcome of surviving infants is growing. Restriction of health care resources has stressed the need for information concerning the effect of individual treatment components on mortality and morbidity. Concern about the quality in apparently normal survivors has been increasing as well. The current flood of papers on these subjects illustrates the interest in these issues. The first part of this paper reviews the methodology used in follow-up studies in the past decades. It aims at methodological problems that hamper comparison between studies and preclude unequivocal conclusions. New treatment techniques seldom were but should be evaluated by randomised trials. To monitor the combined effects of changing obstetric and neonatal techniques on perinatal outcome, studies in geographically defined populations are recommended using data from early pregnancy until at least preschool age. Comparability of outcomes could be enhanced by international agreement on standardisation of assessment methods and outcome measures. In the second part the results concerning gestational age- and birthweight-specific mortality, impairments and disabilities and the risk factors for such disorders are discussed. Increased survival of even the tiniest infants is clearly established. This increase in survival has not yet been accompanied by an apparent increase in major morbidity. However, many minor impairments are reported, occurring often in combination and predisposing these children to deviations of normal development. Important changes in the manifestation of brain damage appear to occur during development. These findings stress the importance of long-term follow-up studies.

Relation of peak total serum bilirubin concentrations to neurodevelopmental outcome at 2 years of age in premature African neonates

As part of a wider survey of the neurodevelopmental outcome of neonates who received intensive care for various morbidities in the Middle-Belt region of Nigeria, the relationship between peak total serum bilirubin (PTSB) concentrations in the neonatal period and neurodevelopmental status at 2 years of age was evaluated in 159 children available for follow-up and assessment. The prevalence of handicaps (minor and major) increased consistently with increase in the PTSB concentration, commencing in the range of 151-200 mumol/l. Major handicaps evolved in association with PTSB concentrations above 201 mumol/l. The handicaps consisted mainly of cerebral palsy and mental retardation. Children with handicaps (minor and major) experienced greater PTSB concentrations than those with a normal neurodevelopmental outcome. The emergence of major handicaps from a mean (SD) moderate peak hyperbilirubinaemia of 241.1 (35.9) mumol/l in the African neonate is worthy of note and cause for concern.

The outcome of extremely low birthweight infants

During the years 1978-89, all surviving extremely low birthweight infants (BW less than 1000 g, ELBWI) in the region of Southern Finland were admitted to the Children's Hospital, University of Helsinki and followed up to six years. The number of liveborn ELBWI increased from 30 to 50/year during the first and last third of the follow-up. During the same twelve year period, the number of the surviving infants increased from 8 to 25/year, with the number and proportion of infants with birthweights of less than 800 g and with gestational ages of less than 27 weeks increasing from 3 to 15/year. Despite of the greater proportion of smaller infants the proportion of infants without intraventricular hemorrhage increased from 50 to 85%. The proportion of children with normal neurodevelopment at two years increased from 40-70% during the first five years of the study, to 63-84% during the last three years of the study. The proportion of children with major disabilities decreased from 28 to 8%. The factors associated with poor neurodevelopment were sepsis, year of birth, intraventricular hemorrhage, and birthweight. The neurological status at one year was a valid predictor of the outcome: at four years 94% of the infants were assessed and normal remained normal as neurologically abnormal remained abnormal or slightly abnormal. The neurologically normal ELBWI were tested at six years: visuomotor coordination was immature in 50%, emotional immaturity was found in 25% and delay of language development in 13%. In our unit increased survival of ELBWI infants has not been associated with an increase in the number of ELBWI infants with handicaps.(ABSTRACT TRUNCATED AT 250 WORDS)

Maternal hypertension and very preterm infants' mortality and handicaps

In a nationwide survey on liveborn very preterm and/or very low birthweight infants in The Netherlands, mortality and handicaps at the corrected age of 2 years were studied in infants born to mothers with or without hypertensive disorders during pregnancy. The neonatal and in-hospital mortality was significantly lower in infants born to hypertensive mothers. In surviving infants, a similar handicap rate was found at the corrected age of 2 years for both groups.

The use of health services in the first 2 years of life in a nationwide cohort of very preterm and/or very low birthweight infants in The Netherlands: rehospitalisation and out-patient care

In a prospective collaborative survey on very preterm (less than 32 weeks) and/or very low birthweight (VLBW) infants (less than 1500 g) in The Netherlands, the use of health services was studied by examining the incidence of and reasons for rehospitalisation and the use of out-patient care, i.e. visits to medical specialists and physical therapists. Out of 1338 liveborn infants originally enrolled in the survey, 998 survived the initial hospital stay. Their use of health services was studied during four period: discharge-3 months, 3-6, 6-12 and 12-24 months corrected for expected date of delivery. A total of 320 infants (34%) was readmitted on 481 occasions. The main reasons for rehospitalisation were surgical procedures, of which inguinal herniorrhaphy was the most prominent, and respiratory tract disorders: 149 admissions (31%) and 147 (31%) admissions respectively. The remaining reasons for rehospitalisation occurred less frequently. In a multivariate analysis, both sex and the length of the initial hospital stay were shown to be significantly associated with an increased risk of rehospitalisation. During the study period, 671 children (67%) attended a medical specialist other than their paediatrician, and 313 children (31%) attended a physical therapist. The use of out-patient services was higher in the first than in the second year of follow-up. The use of health services depended very much on the neurodevelopmental status of the child. In the second year of life, a similar rehospitalisation rate and use of out-patient services was found in the non-impaired children as in children from the general Dutch population.

Normative data and the effect of correction for prematurity on test scores in the psychomotor development of extremely low birthweight infants

This study was concerned with the problem how we should allow for gestational age at birth when evaluating psychomotor development in extremely low birthweight (ELBW) infants. The consequences of the use of corrected and uncorrected developmental test scores as to the degree of prematurity were studied in 27 consecutive ELBW children who had been categorized as being normal on neurological and psychological testing at 5 1/2 years. The present study provides evidence that the overall trend of psychomotor development in normal ELBW children is not accelerated, but is guided by maturation of the central nervous system. This study also suggests that there are no significant differences in the predictive value of corrected and uncorrected DQ scores after 2 years of age with respect to IQ scores at 5 1/2 years.

The male disadvantage in very low birthweight infants: does it really exist?

In a nationwide collaborative study in the Netherlands, perinatal and follow up data were collected on 1338 liveborn very preterm (less than 32 weeks) and/or very low birthweight (VLBW) infants (less than 1500 g). In this group, the mortality risk was similar for both male and female infants. The handicap risk, however, was significantly greater for boys than for girls. This finding could not be explained as being due to the well-known delay in lung maturation in male infants as in idiopathic respiratory distress syndrome and need of assisted ventilation.

Changing outcome of extremely premature infants (less than or equal to 26 weeks' gestation and less than or equal to 750 gm): survival and follow-up at a tertiary center

Management of extremely premature infants is controversial because limits of viability are not established. From 1981 to 1987, 175 infants were admitted to the neonatal intensive care unit at Minneapolis Children's Medical Center with gestational ages less than or equal to 26 weeks and birth weights less than or equal to 750 gm. To assess current prognosis and to analyze trends over time, survival data and developmental characteristics of surviving infants were reviewed. During the study period, antenatal obstetric management was assertive, with liberal indications for tocolysis and expectant management for preterm prolonged membrane rupture, with the goal of delivery of infants in a nonasphyxiated condition. Ninety-one percent of infants were inborn and were managed aggressively after birth with full neonatal support. Survival increased from 21% in 1981-1982 to greater than 50% in 1986-1987 and occurred as early as 23 weeks' gestation. Seventy-one percent of all deaths occurred within 48 hours of birth, and late death (greater than 28 days) was uncommon. At follow-up, 23% of survivors were impaired, a proportion that remained relatively constant during the study period. Improvements in survival were not associated with an increased proportion of impaired infants. Survival with good outcome is attainable at gestational ages and birth weights previously considered nonviable. For obstetricians, neonatologists, and parents, knowledge of such current data can play an important role in making appropriate management decisions for both mother and infant.

Infants weighing 1,000 g or less at birth. Outcome at 8-11 years of age

34 long-term survivors of a five-year period (1977-1981) weighing 1,000 g or less at birth were followed-up at 8-11 years of age. Three (8.8%) children had severe functional handicap, 7 (20.6%) had moderate impairments with the need of special schooling. Twenty-four (70.6%) attended normal school but 7 (20.6%) with need of special help. The rate of survival was 30% at the single regional intensive centre where this cohort of infants were cared for. Handicapped infants differed significantly from infants with good prognosis in their neonatal requirements for oxygen therapy and in pathological conditions such as birth asphyxia and recurrent apneic spells but no differences in birthweight, gestational age, route of delivery, maternal age, social class, proportions below the tenth percentile and sex were found.

Morbidity of very low birthweight infants at corrected age of two years in a geographically defined population. Report from Project on Preterm and Small for gestational age infants in The Netherlands

In a nationwide prospective survey on very preterm and very-low-birthweight infants in the Netherlands, a neurodevelopmental assessment was made at the corrected age of two years in a virtually complete population. The study achieved a 97.4% follow-up rate. A major handicap was found in 59 children and a minor handicap in 111 children (4.4% and 8.3% of liveborn infants, respectively). Unlike mortality, handicap was apparently unrelated to gestational age or birthweight.

Effect of cesarean section on outcome in high- and low-risk very preterm infants

The effect of mode of delivery on the survival and morbidity of 24- to 32-week infants (500-1500 g) was studied in 262 consecutive deliveries. The study population was divided into high-risk (e.g., hypertension) and low-risk (e.g., incompetence of the cervix) groups by evaluation of risk factors. 194 very preterm newborn were classified as high risk and 68 as low risk. In both groups the perinatal outcome of vaginal delivery and cesarean section delivery was compared. Cesarean section was associated with a highly significantly improved survival rate in the high-risk group, but was not associated with differences in fetal outcome in the low-risk group. The results of this study do not support primary cesarean section as the method of delivery for all very preterm fetuses.

Five-year follow-up study of extremely low-birthweight infants

This study investigated whether extremely low-birthweight (ELBW) babies, who at two years had no major handicaps, were at higher risk for intellectual and socio-emotional problems at five years than a control group of children with normal birthweights. There were statistically significant differences between the two groups. The ELBW children were language-delayed, and more active and more intense in their behaviour. There was a tendency for the ELBW children to be lighter and shorter than the controls, but their mean head-circumference was significantly smaller. In general, however, if no serious neurological, neurosensory or cognitive impairment is found among ELBW children at two years, later cognitive and socio-emotional development is likely to be within the normal range.

Long-term outcome of pre-term infants

Recent advances in neonatal intensive care have resulted in significant improvements in the neonatal mortality rate in very low-birth-weight infants. Although there has been some decline in the prevalence of impairments, there are concerns that the improved survival rate may result in handicapped infants who would not have survived in an earlier era. This paper addresses the current survival and morbidity for very low-birth-weight infants and discusses the role of the family physician in meeting the new challenges in continuing care presented by these infants.

An analysis of potential biases in the loss of indigent infants to follow-up

Loss to follow-up is a major problem in indigent inner-city populations. We evaluated a large, well-described, inborn indigent population of high-risk infants (HRI) and control infants (CI) to assess possible selection biases in loss to follow-up at one year adjusted age. Serial clinic visits, phone calls, and letters and payment of $20.00 for attending at 1 year was used to minimize patient loss. Yet, the 1 year loss rate was high, and among HRI, greater for ventilator-treated infants greater than 1500 g birthweight (71/114; 62%) than for ventilator-treated very-low-birthweight (VLBW; less than 1500 g) infants (39/108; 36%) or non-ventilated VLBW infants (62/145; 43%) (P less than 0.05). Multivariate analyses indicated that those lost to follow-up were at no greater risk of a poor outcome on the basis of prenatal and perinatal medical and socioeconomic findings than were those in the same risk group (HRI or CI) or subgroup of HRI who were examined at 1 year. In a review of hospital records, similar rates of hospitalization and neurologic problems during infancy were identified for HRI examined and HRI lost to follow-up. The identification of such morbidity during infancy may be less complete for HRI lost to follow-up than for those examined. Thus, the high frequency of deficits observed in follow-up evaluation of indigent HRI is unlikely to result from loss of unaffected infants.

Consistency and changes in the development of extremely low birthweight infants

Thirty infants who weighed less than 1,000 g were evaluated as to neurological functioning and mental ability at 1 year and, again, at 3 years of age. The results of the examinations showed the high correlation in the neurological status between infancy and the preschool period, particularly, for children who were diagnosed as being clearly normal or abnormal at 1 year. There was a high percentage of psychomotor delays in those with ophthalmic complications.

Mortality, morbidity, growth and development of babies weighing 501-1,000 grams and 1,001-1,500 grams at birth

During the five-year period, January 1980 to December 1984, 149 babies of extremely low birthweight (ELBW; 501-1,000 g) and 296 of very low birthweight (VLBW; 1,001-1,500 g) were admitted to King's College Hospital, Neonatal Intensive Care Unit. The survival rates were 51.7% and 82.8% respectively. There were more peri- and postnatal problems in the ELBW babies than the VLBW babies and these differences were highly significant. All surviving babies born between January 1980 and December 1982 were followed up until aged two. The ELBW children had a higher incidence of neuro-developmental sequelae than those of VLBW especially when both major and minor problems were considered. Their developmental quotients were lower at one and two years. Significantly more ELBW children were of short stature and low weight (less than 3rd centile). By two years of age the differences between ELBW and VLBW children in stature and mean DQ had lessened.

Neurodevelopmental screening of in utero growth-retarded prematurely born children before school age

As part of a prospective follow-up study of two premature cohorts (gestational age less than or equal to 36 weeks) born between 1976 and 1977, designed to evaluate the effects of IUGR on morbidity, mortality and neurological development in prematurely born children, 71 prematurely born children (48 AGA, 23 IUGR) without major neurological handicaps were subjected to detailed assessment of their neurological and psychological status at the age of 4 years. Thirty-six healthy full-term children formed a control group. The socioeconomic status of the families of the premature groups was similar to that of the families of the control group. The assessment consisted of a neurodevelopmental screening test and four psychological tests. Validation of the NDS test in relation to proven cognitive problems (sensitivity 96%, specificity 64%, relative risk 16.74) and determination of normal ranges were based on findings in the control group. There were significantly more children with moderate to high risk scores (greater than or equal to 10) among the IUGR group than among the AGA group. The neurodevelopmental profile of the preterm IUGR group was characterized by complex deviations of motor, visual and perceptual functions from normal. Preterm AGA children had only slightly higher risk scores in relation to fine motor, upper motor and perceptive functions than control children. Of the various perinatal factors studied, IUGR (especially in relation to boys who needed respirator therapy) was the most likely to be associated with abnormal NDS scores before school age.

Obstetric variables predicting survival of the immature newborn (less than or equal to 1000 gm): a five-year experience at a single perinatal center

The immature neonate constitutes less than 3% of total births and yet accounts for almost 50% of all perinatal deaths. In a 5-year period, 476 consecutive live and inborn neonates weighing less than or equal to 1000 gm were studied. The purpose of this study was to describe our experience with these pregnancies and determine the obstetric predictors of survival. Statistical methods of univariate and multivariate analysis were used. Survival was defined as the discharge home of an alive infant. The overall survival rate without exclusions was 40.3%. The following variables were most significant and accurately predicted survivors in 76.2% and nonsurvivors in 69.2% of cases: a combination of birth weight, 5-minute Apgar score, gestational age, cervical dilatation on admission, sex, a more recent study time interval, and race. Of the factors studied, the following were directly related to advancing gestational age and birth weight: higher Apgar scores at 1 and 5 minutes, increased operative delivery rate, and increased frequency of tocolysis and glucocorticoid usage; of these factors, only the 5-minute Apgar score remained statistically significant, when controlling for gestational age and birth weight by multivariate analysis.

Children of birth weight less than 1000 g: changing outcome between ages 2 and 5 years

Of 55 consecutive long-term survivors of birth weight 500 to 999 g, complete psychologic and pediatric data were available for 54 children at 2 years corrected age and for 50 at age at least 5 1/2 years. At the latter age, 60% (30 of 50) were not impaired, 10% (five of 50) had severe sensorineural or intellectual impairments, 10% (five of 50) had mild to moderately impairment, and 20% (10 of 50) had minor neurobehavioural abnormalities. Sensorineural deafness in one child and bilateral blindness in one remained stable over time, but of six children with spastic cerebral palsy at 2 years, only three retained this diagnosis at 5 1/2 years. The mean Mental Developmental Index (MDI) on the Bayley Scales at 2 years was 91.1, significantly below the test mean; by 5 1/2 years the mean full scale of the Wechsler Preschool and Primary Scales of Intelligence (WPPSI) was 101.8. The MDI correlated highly with the full-scale WPPSI (r = 0.7), but for individual children it was not always an accurate predictor of 5-year ability. Between 2 and 5 1/2 years there was a substantial reordering within four categories of impairment: findings in 27 children were improved, four were judged to become more severely impaired over time, and 19 did not change. We conclude that our 2-year assessment often underrated the potential of the children as expressed at 5 1/2 years, and that 2 years is too early for reliable classification of children of birth weight 500 to 999 g.

Shunt in high-risk newborns

Twenty-four high-risk newborns with a low birth weight developed progressive hydrocephalus and underwent ventriculoperitoneal shunting (at the time of shunting they weighed 1,100-1,900 g, mean 1,541 g). The changes in hydrocephalus after shunting were determined by ultrasound examinations; preoperative examination was by CT. Of the factors evaluated for their relationship to shunt complication, we considered in particular babies with a CSF protein level of over 1.5 g/l (7 cases). These cases were treated with external drainage and later with ventriculoperitoneal shunting. Shunt infections occurred in 20.9%, in contrast with a low incidence of shunt blockage (8.3%), probably owing to previous external shunting in children with high CSF protein. There were 2 deaths (8.3%). All children underwent careful follow-up during the 1st year and serial checkups subsequently for 5 years.

Prognosis for infants born at 23 to 28 weeks' gestation

The survival and neurodevelopmental outcome of 356 extremely preterm infants born at 23 to 28 weeks' gestation were reported by week of gestation. Their corrected 1 year survival improved from 7% at 23 weeks to 75% at 28 weeks. The overall incidence of impairment was 19% and of major disability 12%. Boys had a significantly lower normal survival than girls. Multiple births had a significantly lower survival and higher incidence of impairment than singleton births. Predictions of outcome were made before delivery, after resuscitation, and at 1 week to aid the development of guidelines on when perinatal intensive care is justified, whether obstetric intervention for fetal reasons is warranted, and what initial and ongoing prognoses to give to parents. Intensive care for progressively smaller and more immature infants, many of whom were previously considered non-viable, needs to be carefully monitored by every perinatal centre.

Outcome of extremely-low-birthweight infants

The overall 1-year survival rate of 261 infants born at 500 g-999g over a 7-year period was 46%. The survival rate of the 220 inborn infants, corrected for birth defects, would have increased from 47% to 57% if delivery room deaths were excluded and to 62% if postneonatal deaths had also been ignored. Survival improved progressively with increasing 100g weight groups. The disability rate in the 108 survivors who were at least 2 years old corrected for prematurity was 28% with little variation between the 100g weight groups. There were no significant trends in annual perinatal mortality, 1-year survival and disability rate in survivors over the study period for the inborn population. The male infants had significantly lower normal-survival rate than the female infants. Small-for-gestational-age infants, comprising 11% of the inborn group, had significantly better survival but a higher disability rate. Multiple births had significantly lower survival and normal-survival rates than had singleton births. Infants whose mothers were transferred for delivery at the perinatal centre before onset of labour had a significantly better survival rate than those whose mothers had 'booked' and those who were transferred in labour.

Predictors for survival and normal neurodevelopmental outcome of infants weighing less than 1001 grams at birth

Between 1979 and 1981, 67 infants weighing 1000 g or less at birth were admitted to the Hammersmith Hospital Neonatal Intensive Care Unit. 29 survived the neonatal period. Low acidosis score, without a metabolic component, was the most powerful predictor of survival. Other factors were gestational age, five-minute Apgar score, the need for ventilatory support, hypoxia, hypercapnia, pneumothorax, hypotension and the presence of a larger PVH. Of the 24 survivors followed up to three years of age, 11 were optimal, nine had some neurodevelopmental deficits and three had moderate functional handicap. Only one child has cerebral palsy and global mental retardation. Five-minute Apgar score and the presence of PDA correlated with normal outcome. None of the 20 obstetrical factors examined appeared to influence either survival or neurological outcome.

Neurodevelopmental assessment of very low birth weight neonates: effect of germinal matrix and intraventricular hemorrhage

During a recent 36-month interval, all neonates of less than or equal to 1250 gram birth weight who were admitted to our Newborn Special Care Unit and survived the first 36 postnatal hours underwent either computed tomography or echoencephalography or both for the assessment of neonatal germinal matrix hemorrhage and intraventricular hemorrhage. Seventy of the 164 long-term surviving infants experienced neonatal germinal matrix and/or intraventricular hemorrhage (GMH/IVH Group), whereas 94 infants had studies that were negative (Non-hemorrhage Group). Serial neurodevelopmental assessments were performed on 142 (87%) of the 164 long-term surviving infants; these assessments included the Bayley Scales of Infant Development at 3, 6, 12, and 18 months (corrected age) and the Stanford-Binet and Peabody Picture Vocabulary examinations at 30 months (corrected age). At 30 months (corrected age), the incidence of major neurologic abnormalities was extremely low in both the GMH/IVH and the Non-hemorrhage groups. In addition, although there were few survivors of the more severe grades of intraventricular hemorrhage, we could detect no difference between the developmental scores of the GMH/IVH and the Non-hemorrhage Group infants.

Comparison of abilities of preterm and maturely born children at 5 years of age

This study investigated whether the development of 5 year old preterm born children was appropriate for age and equivalent to or different from their peers who were full term at birth. At the adjusted age of 5 years, the development of 106 children born 5 or more weeks before term was compared with the development of 103 children who were born at term. This latter group of children were matched to the preterm group in sex, year of birth, birthplace, race and residential location. No cerebral palsy children were included in either subject group. The results indicated a significant difference between the two groups. Factors distinguishing the preterm children from their full term peers included small involuntary hand movements, less competent gross motor ability, poorer verbal performance and more variability in behaviour, postural response and balance. A higher than average incidence of minor motor, speech, behaviour and learning problems in early school years is probable.

Perinatal factors associated with death or handicap in very preterm infants

That death or major developmental handicap is associated with prematurity and low birth weight is well recognized. The importance of other perinatal factors related to presentation and management, however, is far from certain. In an attempt to elucidate the importance of some of these factors, data from 383 live-born infants delivered at 26 to 30 weeks' gestation were analyzed. All infants were born in a tertiary perinatal unit and long-term follow-up had been carried out on the survivors for at least 1 year. A group of 39 infants who died in the neonatal period and 34 infants with long-term handicap were compared with matched normal control infants. Perinatal factors related to outcome were analyzed and it was found that, while initial poor condition at birth was correlated with death, there were few predictors of subsequent handicap. More refined methods of both prenatal and neonatal assessment are required to define these factors.

Outcome in infants 501 to 1000 gm birth weight delivered to residents of the McMaster Health Region

The mortality and morbidity for all 255 live births of infants with birth weight 501 to 1000 gm and delivered to residents of a geographically defined region between 1977 and 1980 are reported. In all, 117 (46%) infants were discharged alive; there were four postdischarge deaths, and three infants were lost to follow-up. The mean birth weight and gestational age of the survivors was 850 +/- 118 gm and 27.1 +/- 2 weeks, respectively. Neurosensory handicaps were detected in 26 (24%) of 110 survivors followed for a minimum of 2 years corrected age. In addition, 29 (26%) infants had nonneurologic problems and 55 (50%) were considered apparently normal. Within 100 gm birth weight groups, survival improved significantly with increasing birth weight, but the handicap rate among survivors remained relatively constant. These figures are proposed for use in describing the current prognosis at birth for liveborn tiny infants from comparable unselected populations.

Special considerations in the nursing care of the very low birth weight infant

Improvement in obstetric and neonatal care has resulted in an increase in the number of very low birth weight infants (less than 1000 grams) being cared for in neonatal intensive care units. This article addresses issues related to the special nursing implications required in the care of these infants.