Very Low Birth Weight Survivors Research Articles

Neuroprem 2: An Italian Study of Neurodevelopmental Outcomes of Very Low Birth Weight Infants.

Background: Despite the increased survival of preterm newborns worldwide, the risk of neurodevelopmental disabilities remains high. Analyzing the outcomes of the preterm population can identify risk factors and enable specific early interventions.Aims: Neuroprem is a prospective cohort study of very low birth weight (VLBW) infants that aims to evaluate the neurodevelopmental outcomes and risk factors for severe functional disability at 2 years of corrected age.Methods: Nine Italian neonatal intensive care units participated in the network. The Griffiths Mental Developmental Scales (GMDS-R) or the Bayley Scales of Infant and Toddler Development (BSDI III) and a neuro-functional evaluation (according to the International Classification of Disability and Health and Neuro-Functional Assessment, or NFA ICF-CY) were administered to VLBW infants at 24 months of corrected age. The primary outcome measure was severe functional disability, defined as cerebral palsy, bilateral blindness, deafness, an NFA ICF-CY of >2, a BSDI III cognitive composite score of <2 SD, or a GMDS-R global quotient score of <2 SD. Perinatal risk factors for severe functional disability were assessed through multivariate logistic regression analysis.Results: Among 502 VLBW survivors who completed the 24-month follow-up, 48 (9.6%) presented severe functional disability, of whom 27 had cerebral palsy (5.4%). Rates of severe functional disability and cerebral palsy were higher in neonates with a lower gestational age (p < 0.001). Overall, 147 infants (29.3%) were referred to neuromotor intervention. In the multivariate regression model, gestational age at birth OR 0.79; 95% CI 0.67–0.90; p = 0.001) and periventricular-intraventricular hemorrhage (OR 2.51; 95% CI 1.19–5.26; p = 0.015) were significantly associated with severe functional disability.Conclusion: Neuroprem 2 provides updated information on the neurodevelopmental outcomes of VLBW infants in a large Italian cohort. The overall rate of neurodevelopmental disabilities was quite lower than reported in the previous literature. These data indicate the need for structured follow-up programs from a national neonatal network perspective.

Reduced Exercise Capacity in Adults Born at Very Low Birth Weight: A Population-based Cohort Study

Rationale: Population-based data regarding the consequences of very low birth weight (VLBW) and bronchopulmonary dysplasia (BPD) on adult exercise capacity are limited. Objectives: To compare exercise capacity in a national VLBW cohort with term-born controls and explore factors contributing to the differences. Methods: At 26-30 years of age, 228 VLBW survivors and 100 controls underwent lung function tests, cardiopulmonary exercise testing, and assessment of resting cardiac structure and function using echocardiography. Data on self-reported physical activity were collected. Measurements and Main Results: Compared with controls, adults with VLBW demonstrated reduced oxygen uptake, work rate, and oxygen pulse at peak exercise (9.3%, 10.7%, and 10.8% lower, respectively) and earlier anaerobic threshold (all P < 0.0001), with all mean values within normal range. VLBW survivors showed reduced physical activity, impaired lung function (reduced FEV1, FEV1/FVC, and DlCO), altered left ventricular structure and function (reduced mass, size, stroke volume, and cardiac output), and reduced right atrial and ventricular size. Adjustment for the combination of three sets of covariates (physical activity with body mass index, lung function, and cardiac structure and function) explained most of the exercise group differences. Beyond the effects of physical activity and body mass index, lung function and cardiac structure and function contributed approximately equally. BPD with other prematurity-related perinatal factors (ventilation, antenatal steroids, extremely low birth weight, and extreme preterm) were not associated with a reduced exercise capacity. Conclusions: Exercise capacity was significantly reduced in adults with VLBW, which we speculate is from combined effects of impaired lung function, altered heart structure and function, and reduced physical activity. Perinatal factors including BPD were not associated with a reduced exercise capacity.

Lung Function of Adults Born at Very Low Birth Weight.

Much remains unknown about the consequences of very low birth weight (VLBW) and bronchopulmonary dysplasia (BPD) on adult lungs. We hypothesized that VLBW adults would have impaired lung function compared with controls, and those with a history of BPD would have worse lung function than those without. At age 26 to 30 years, 226 VLBW survivors of the New Zealand VLBW cohort and 100 term controls born in 1986 underwent lung function tests including spirometry, plethysmographic lung volumes, diffusing capacity of the lung for carbon monoxide, and single-breath nitrogen washout (SBN2). An obstructive spirometry pattern was identified in 35% VLBW subjects versus 14% controls, with the majority showing mild obstruction. Compared with controls, VLBW survivors demonstrated significantly lower forced expiratory volume in 1 second (FEV1), FEV1/forced vital capacity (FVC) ratio (FEV1/FVC), forced expiratory flow at 25% to 75% of FVC and higher residual volume (RV), RV/total lung capacity (TLC) ratio (RV/TLC), decreased diffusing capacity of the lung for carbon monoxide, and increased phase III slope for SBN2. The differences persisted after adjustment for sex and smoking status. Within the VLBW group, subjects with BPD showed significant reduction in FEV1, FEV1/FVC, and forced expiratory flow at 25% to 75% of FVC, and increase in RV, RV/TLC, and phase III slope for SBN2, versus subjects without. The differences remained after adjustment for confounders. Adult VLBW survivors showed a higher incidence of airflow obstruction, gas trapping, reduced gas exchange, and increased ventilatory inhomogeneity versus controls. The findings suggest pulmonary effects due to VLBW persist into adulthood, and BPD is a further insult on small airway function.

Neurodevelopmental Outcomes of Very Low Birth Weight Infants at 18-24 Months, Corrected Gestational Age in a Tertiary Health Centre: A Prospective Cohort Study.

To determine the prevalence and risk factors for poor neurodevelopmental outcome in a cohort of very low birth weight (VLBW) infants. Four hundred and twenty-two infants of a total of 643 VLBW survivors from a teaching hospital in South India were followed up to assess their neurodevelopmental outcomes. Among the 422 children who completed the assessment, results of 359 children whose assessments were done between 18 and 24 months were analysed. Thirty-seven children (10.31%) had poor neurodevelopmental outcome, six children [1.67%] had cerebral palsy, one child had visual impairment and another had hearing impairment. Poor post-natal growth was independently associated with poor neurodevelopmental outcomes in the multivariate analysis (p = 0.045). Neonatal complications were not associated with the developmental outcome. Despite lower rates of neonatal complications compared with Western cohorts, significant proportion of VLBW infants had poor neurodevelopmental outcomes. Poor post-natal growth was an important determinant of the developmental outcome.

Very low birth weight survivors have reduced peak bone mass and reduced insulin sensitivity

Increasing numbers of very low birth weight (VLBW) infants are surviving into adulthood because of improvements in neonatal intensive care. Adverse events in early life can have long-term effects through reprogramming of metabolic systems. To determine whether young adult VLBW survivors have abnormalities of skeletal development or endocrine function. Cross-sectional, observational, case-control study. Thirty-seven VLBW subjects and 27 healthy controls at peak bone mass (mean age 23). Differences between cases and controls in body size, body composition, bone mass and bone geometry [assessed by dual-energy X-ray absorptiometry (DXA), hip structure analysis and peripheral quantitative computed tomography (pQCT)], bone turnover [urine N-terminal telopeptide of type I collagen (NTX), serum C-terminal telopeptide of type I collagen (CTX)], aminoterminal propeptide of type I procollagen (PINP) and bone alkaline phosphatase), hormones (sex steroids, IGF-1, PTH and 25-OH vitamin D) and insulin sensitivity (HOMA-IR and oral glucose tolerance testing). VLBW subjects had lower bone density at the lumbar spine (5.7%) and femoral neck (8.6%), which persisted after correction for bone size by the estimation of volumetric density (bone mineral apparent density). Urine NTX was higher in VLBW subjects than in controls, but there were no significant differences in other bone turnover markers. VLBW survivors had lower insulin sensitivity (mean INS-30 controls = 57.0, VLBW subjects = 94.3, P < 0.01), but there were no differences in whole body fat mass or truncal fat mass between VLBW subjects and controls. Young adult VLBW survivors have reduced bone density for their bone size and reduced insulin sensitivity, which may have significant implications for their risk of fracture and diabetes in later life.

Perinatal profile of very low birthweight infants under a universal newborn hearing screening programme in a developing country: A case-control study

Objective: To determine the perinatal profile and developmental risks of very low birth weight (VLBW) infants (≤1500 g) under a universal hearing screening programme in a resource-poor country.Methods: A case-control study of VLBW survivors matched by date of birth and sex with normal birth weight (≥2500 g) infants delivered in an inner-city maternity hospital in Lagos, Nigeria. Hearing status was determined by two-stage screening with transient evoked otoacoustic emissions (TEOAE) followed by automated auditory brainstem response (AABR). Maternal and infant factors associated with VLBW were determined using unconditional and conditional multivariable logistic regression analyses.Results: All 45 VLBW singletons (mean weight 1.3 ± 0.1 kg) during the study period were matched with 225 controls (mean weight 3.4 ± 0.5 kg). VLBW was associated with maternal occupation, lack of antenatal care, low 5-minute Apgar score and hyperbilirubinemia based on unmatched and matched analyses. Additionally, VLBW infants were significantly associated with failed or incomplete hearing screening outcomes. Four (10.5%) of the 38 infants tested with AABR failed, but none returned for diagnostic evaluation and one child had previously passed TEOAE.Conclusions: VLBW infants in resource-poor settings are associated with the risk of sensorineural hearing loss and other perinatal outcomes that may potentially compromise their optimal development in early childhood.

Combining clinical assessment scores and in vivo MR spectroscopy neurometabolites in very low birth weight adolescents

Very low birth weight (VLBW) survivors are at increased risk of neurological impairments that may persist into adolescence and adulthood. The aims of this study were to identify the most important clinical assessments that characterize differences between VLBW and control adolescents, and to look at the relationship between clinical assessments and the metabolites in in vivo MR spectra. At 14-15 years of age, 54 VLBW survivors and 64 term controls were examined clinically. Several neuropsychological and motor assessments were performed. The magnetic resonance (MR) brain spectra were acquired from volumes localized in the left frontal lobe and contained mainly white matter. Probabilistic neural networks and support vector machines demonstrated that clinical assessments rendered a possibility of the classification of VLBW versus control adolescents. The most important clinical assessments in this classification were visual-motor integration, motor coordination, stroop test, full scale IQ, and grooved pegboard. Through the use of outer product analysis-partial least squares discriminant analysis on a subset of adolescents (n=36), the clinical assessments found to most strongly correlate with the spectral data were the global assessment scale, Wisconsin card sorting test, full scale IQ, grooved pegboard test, and motor coordination test. Clinical assessments that relate to spectral data may be especially dependent on an intact microstructure in frontal white matter.

Extrauterine Growth Restriction: A Review of the Literature

Extrauterine growth restriction (EUGR) is a common condition in very low birth weight (VLBW) preterm infants (< or = 1,500 g). Most affected infants have a birth weight that is average for gestational age, but by the time of hospital discharge have a weight that is less than the tenth percentile for corrected gestational age. EUGR is the most frequent morbidity among VLBW survivors at their time of discharge from the hospital. Studies to elucidate the causes of EUGR have been inconclusive. Recent research has found an association between EUGR, developmental outcomes, and long-term morbidity. Low birth weight has also been associated with chronic diseases later in life. These findings emphasize the critical nature of understanding the phenomenon of EUGR and ways it can be prevented.

Growth During the First Two Years Predicts Pre-School Height in Children Born With Very Low Birth Weight (VLBW): Results of a Study of 1,320 Children in Germany

Children born with very low birth weight (VLBW) are at risk of impaired growth. We aimed to study VLBW survivors (90.8%) born in 1998/1999 in the state of Baden-Württemberg (n = 2103) for whom growth data were available up to age six. Classification as appropriate for gestational age (AGA) or small for gestational age (SGA) depended on size at birth. Models to predict height SDS at 5 y were developed using data for 1 yr (Model 1) and 2 yrs (Model 2). The data of 1320 (63%) children were available: SGA: n = 730, AGA: n = 590. At 6 yrs, 8.3% AGA and 13.4% SGA children were short (<-2.0 SDS). The following factors explained Ht SDS at 5 (and 6) yrs (order of importance): (a) Model 1 (n = 1033; R2 = 0.52; error: 0.84 SDS): 1st yr Ht SDS, mid-parental height (MPH) SDS, 1 yr weight SDS, birth weight SDS; (b) Model 2 (n = 991; R2 = 0.72; error: 0.65 SDS): 1st yr Ht SDS; change (2nd yr) in Ht and weight SDS; MPH SDS; 1st yr weight SDS; birth weight SDS. Thus, some AGA and SGA children born VLBW remain short and preventive strategies need to be developed for those at risk.

Growth and adrenal androgen status at 7 years in very low birth weight survivors with and without bronchopulmonary dysplasia

Aims: To evaluate whether 7 year old VLBW (very low birth weight, <1500 g) survivors with and without bronchopulmonary dysplasia (BPD) evince similar growth status and higher adrenal androgen (AA)...

The challenge pays off: Early enhanced nutritional intake for VLBW small-for-gestation neonates improves long-term outcome

The challenge pays off: Early enhanced nutritional intake for VLBW small-for-gestation neonates improves long-term outcome

Late-onset sepsis in very low birth weight neonates: the experience of the NICHD Neonatal Research Network.

Late-onset sepsis (occurring after 3 days of age) is an important problem in very low birth weight (VLBW) infants. To determine the current incidence of late-onset sepsis, risk factors for disease, and the impact of late-onset sepsis on subsequent hospital course, we evaluated a cohort of 6956 VLBW (401-1500 g) neonates admitted to the clinical centers of the National Institute of Child Health and Human Development Neonatal Research Network over a 2-year period (1998-2000). The National Institute of Child Health and Human Development Neonatal Research Network maintains a prospective registry of all VLBW neonates admitted to participating centers within 14 days of birth. Expanded infection surveillance was added in 1998. Of 6215 infants who survived beyond 3 days, 1313 (21%) had 1 or more episodes of blood culture-proven late-onset sepsis. The vast majority of infections (70%) were caused by Gram-positive organisms, with coagulase-negative staphylococci accounting for 48% of infections. Rate of infection was inversely related to birth weight and gestational age. Complications of prematurity associated with an increased rate of late-onset sepsis included patent ductus arteriosus, prolonged ventilation, prolonged intravascular access, bronchopulmonary dysplasia, and necrotizing enterocolitis. Infants who developed late-onset sepsis had a significantly prolonged hospital stay (mean length of stay: 79 vs 60 days). They were significantly more likely to die than those who were uninfected (18% vs 7%), especially if they were infected with Gram-negative organisms (36%) or fungi (32%). Late-onset sepsis remains an important risk factor for death among VLBW preterm infants and for prolonged hospital stay among VLBW survivors. Strategies to reduce late-onset sepsis and its medical, social, and economic toll need to be addressed urgently.

Predictors of neurodevelopmental outcome of Malaysian very low birthweight children at 4 years of age.

To determine neonatal, early developmental and social risk factors that predict the neurocognitive and behavioural outcome of very low birthweight (VLBW) preschool children at four years of age. From a cohort of 151 eligible VLBW survivors born in Kuala Lumpur Maternity Hospital, 116 (76.8%) were prospectively followed up from birth till four years. A standardised neurological examination was performed at one and four years to determine the presence of impairment and cerebral palsy, respectively. Cognitive development was assessed using the Mental Scale of the Bayley Scales of Infant Development (MDI) at one year and the Weschler Preschool and Primary Scale of Intelligence-Revised (WIPPSI-R) at four years. Motor coordination was assessed using the Movement Assessment Battery for Children (Movement-ABC). Mothers completed the Child Behaviour Checklist (CBCL) and Parenting Stress Index (PSI) questionnaires. Logistic and multiple regression analyses were used to determine factors associated with cerebral palsy, IQ scores, Movement-ABC and CBCL scores. Factors associated with cerebral palsy were lower MDI scores at one year (P = 0.001) and late neonatal cranial ultrasound abnormalities (P = 0.036). Minor (P = 0.016) or major impairment (P = 0.003) at one year of age and a low level of paternal education (P = 0.01) were associated with poor motor function on the Movement-ABC scale. Lower levels of maternal education (P < 0.001), impairment at one year (P = 0.002) and late neonatal cranial ultrasound abnormalities (P = 0.039) predicted Full Scale IQ scores. Higher PSI scores (P = 0.001), younger mothers (P = 0.003) and late neonatal cranial ultrasound abnormalities (P = 0.009) were associated with worsened child behaviour scores on the CBCL scale. Social factors and the caregiving environment were important determinants of cognitive and behavioural outcome. Cranial ultrasound abnormalities in the late neonatal period and the developmental status at one year might be useful in identifying high risk infants in need of long-term surveillance.

Vitamin A supplementation in very low birth weight neonates: rationale and evidence.

Bronchopulmonary dysplasia (BPD) is the most prevalent form of chronic lung disease in infancy. Among the 3.9 million births in the United States in 1997, approximately 55 000 newborn infants weighed <1500 g at birth.1 Among these very low birth weight (VLBW) infants, 49 000 infants would be expected to be discharged alive at the end of their first hospitalization (Vanderbilt experience 1998). At an estimated incidence of 24% among the VLBW survivors (Vanderbilt experience 1998), 12 000 new cases of BPD would be expected to emerge annually, making BPD the leading cause of chronic lung disease in infancy. The pathogenesis of BPD involves factors causing injury to an immature lung and factors inhibiting its healing.2,,3 The lung injury can result from such insults as hyaline membrane disease, barotrauma or volutrauma from mechanical ventilation, oxygen toxicity, and airway infection associated with prolonged tracheal intubation.4 The lung healing can be influenced by nutrients, antioxidants, inflammatory cells, eicosanoids, growth factors, peptide hormones, and components of extracellular matrix.5 The role of the essential micronutrient vitamin A (retinol) in the promotion of orderly growth and differentiation of regenerating epithelial tissues makes vitamin A an important nutrient during recovery from lung injury.6,,7 This review focuses on the pathophysiology of vitamin A deficiency in relation to BPD, examines the evidence for vitamin A deficiency in VLBW neonates, and provides guidelines for vitamin A supplementation as an approach toward amelioration of lung disease among the VLBW survivors. Vitamin A promotes normal growth and differentiation of epithelial cells. Vitamin A deficiency, therefore, affects various organ systems, including the lung.6 The histopathologic changes in the respiratory system generally precede other consequences of vitamin A deficiency involving the genitourinary system, eye, and skin.6 Vitamin A deficiency results in a progressive sequence of …

Respiratory health, lung function, and airway responsiveness in school-age survivors of very-low-birth-weight.

The purpose of this study was to determine the respiratory symptoms, pulmonary function, and airway reactivity in school-age survivors of very-low-birth-weight and to describe the influence of birth weight and perinatal illness on their pulmonary function. Thirty (of 39) 10- to 11-year-old survivors of very-low-birth-weight (VLBW) recruited at birth into a prospective longitudinal study of development; 30 (of 32) normal-birth-weight peers recruited from the same school or census tract as the VLBW group at age 5; and 15 normal-birth-weight siblings of the VLBW group participated in the study. Outcome measures were mother's reports of respiratory health; forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1); FEV1/FVC; forced expiratory flow, midexpiratory phase (FEF25-75); peak expiratory flow rate (PEFR); and tolerance to methacholine. There were no differences between groups in mothers' reports of current respiratory health. Pulmonary function values were lower for the VLBW survivors but significant only for FEF25-75 (F = 4.13; P = 0.02). Number of days in the intensive care nursery correlated significantly with decreased FEV1 (r = -.40, df = 28, P = 0.03), FEV1/FVC (r = -.37, df = 28, P = 0.04, and FEF25-75 (r = -.39, df = 28, P = 0.03). Only the relationship between length of nursery stay and FEV1/FVC was independent of birth weight. Number of days on mechanical ventilation was significantly correlated with decreased FEV1 (-.44, df = 28, P = 0.01), FEV1/FVC (r = -.38, df = 28, P = 0.04), FEF25-75 (r = -.44, df = 28, P = 0.01, and PEFR (r = -.40, df = 28, P = 0.03). All of these relationships were independent of birth weight. There were no significant associations between perinatal risk factors and methacholine responsiveness. Differences between VLBW children and normal-birth-weight children in pulmonary function are modest even when statistically significant. Severity of perinatal illness influences pulmonary function parameters into late childhood.

A longitudinal study of developmental outcome of infants with bronchopulmonary dysplasia and very low birth weight.

Bronchopulmonary dysplasia (BPD) is now the leading cause of lung disease in US infants. In a large regional cohort, we tested the hypothesis that despite innovations in neonatal care, very low birth weight (VLBW) infants (<1500 g) with BPD had poorer developmental outcomes than nonaffected infants during the first 3 years of life, and that BPD predicted poorer outcome beyond the effects of other risk factors. Three groups of infants (122 with BPD, 84 VLBW without BPD, and 123 full-term) were followed longitudinally to 3 years of age with the Bayley Scales of Mental and Motor Development. Comparison groups of VLBW infants without BPD and full-term infants did not differ in sex, race, or socioeconomic status. Statistical analyses included hierarchical and stepwise multiple regression. Infants with BPD performed more poorly at all ages. By 3 years, cognitive and/or motor development was in the range of retardation (<70 standard score) for 21% to 22% of infants with BPD. In multiple regression analyses controlling for socioeconomic and neonatal risk conditions, BPD had an independent negative effect on motor outcome at 3 years. Neurologic risk, a summary measure of neurologic problems other than intraventricular hemorrhage, and the presence of BPD independently predicted motor delay. By 3 years, social class, race, and neurologic risk predicted mental outcome, suggesting that the specific effects of BPD are primarily on the motor domain. In VLBW infants, BPD predicts poorer motor outcome at 3 years, after control for other risks. Cohorts of infants with BPD also had higher rates of mental retardation, associated with greater neurologic and social risk. These findings underscore the need for intensive prevention and habilitation efforts for this growing group of VLBW survivors, as well as investigation into the potential role of BPD in the higher rates of learning disabilities in VLBW cohorts at school age.

Bronchopulmonary dysplasia in very low birthweight infants

The incidence, clinical presentation and severity of bronchopulmonary dysplasia (BPD) in 110 consecutive very low birthweight (VLBW) infants admitted to the National University Hospital Neonatal Intensive Care Unit between October 1985 and January 1989 is reviewed. Thirty-two infants died, giving an overall survival rate of 70.9%. Sixty infants (54.4%) required mechanical ventilation in the first week of life; 24 (40%) of these infants died. Of the 36 survivors, 23 required oxygenation at 28 days of life and 21 fulfilled the criteria for BPD (35% of the 60 ventilated and 58% of the survivors). The incidence of BPD in all VLBW infants is 19% and of VLBW survivors 27%. Birthweight and gestational age appear to be important determinants. All the survivors in the 501-750 g birthweight group developed BPD compared to 6.25% in those above 1250 g. None of those greater than 30 weeks gestation developed BPD. Two forms of BPD were observed; the 'severe' group presented radiologically with chest radiographs characteristic of Stage IV BPD, while the 'mild' group with small or normal sized lungs demonstrated irregular strands of radio-densities alternating with areas of normal or increased lucency. The duration of mechanical ventilation and oxygen dependency were significantly longer in the 'severe' group, with the mean maximum peak inspiratory pressure, mean airway pressure, and FiO2 required in the first week of life being also significantly higher. Hyaline membrane disease was the main cause of respiratory failure requiring ventilation. The other causes were persistent pulmonary hypertension (1) and apnoea of prematurity (3); all of the latter developed only mild BPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved outcome to two years of very low-birthweight infants: fact or artifact?

In 1966-70, the survival rate for very low-birthweight (VLBW) children born in a tertiary perinatal centre was 37.1 per cent but by 1980-82 it had increased to 68.3 per cent. The latter cohort had a significantly reduced prevalence of strabismus, myopia and a head circumference under the 10th percentile, but a significantly increased prevalence of cerebral palsy compared with the 1966-70 VLBW children. Survivors born in 1980-82 had a significantly increased mean Mental Development Index (MDI) on the Bayley Scales compared with the sub-group of survivors born in 1968-70 but there was also a significant improvement in mean MDI over time for a group of normal-birthweight children. No improvement of MDI scores of VLBW survivors in the 1980-82 cohort could be attributed solely to perinatal care. The two-year-old VLBW children in the 1980-82 cohort had similar rates of sensorineural impairments, disabilities and mean MDI to those who would have survived with the care available in 1966-70. It is concluded that survival of VLBW infants has improved in recent times but that neurodevelopmental outcome still lags behind that of normal-birthweight peers.

Retrolental fibroplasia--controlled study of 4 years' experience in a neonatal intensive care unit.

During the 4 years 1977-80, 14 infants developed retrolental fibroplasia (RLF) in the neonatal unit at this medical centre. All were very low birthweight (VLBW) infants who weighed 1500 g or less at birth. The incidence of RLF was 3.5% for all VLBW infants admitted for neonatal intensive care and 4.7% for VLBW survivors. The mean birthweight of the affected infants was 970 (range 730-1310) g and mean gestational age 26 (range 24-29) weeks. Seven of the affected infants (2.4% of VLBW survivors) had significant scarring with temporal dragging of the optic disc and retinal detachment. Each of the 14 infants was matched with 2 control infants in order to see whether any factors predisposing to the development of RLF, including those related to oxygen therapy and monitoring, could be identified. The only factor associated with RLF was a higher volume of blood given with replacement transfusions. The occurrence of RLF was unrelated to an increase in requirement for or duration of oxygen therapy, arterial oxygen tensions as determined by intermittent sampling, or the availability of transcutaneous oxygen monitoring. The care taken in oxygen therapy may have been responsible for failure to show a quantitative association between hyperoxaemia and RLF. Although the problem of oxygen therapy in preterm infants is far from being resolved, current neonatal intensive care methods have limited the occurrence of RLF to VLBW infants. This study demonstrated a lower incidence of RLF in VLBW infants despite an improved survival rate compared with that previously reported.

Perinatal asphyxia and outcome of very low birthweight infants.

Seventy-eight very low birthweight (VLBW) infants (whose birthweights were 1500 g or less) were admitted to the Neonatal Special Care Unit in 1977. Seventy-two of them required treatment in the intensive care area; these represented 40% of admissions to that area of the Unit. The mortality rate was 20% for infants weighing 1001 g to 1500 g, and 52% for those weighing 501 g to 1000 g. An Apgar score of 0 to 3 at two minutes and five minutes was reported in 34% and 19% of VLBW infants respectively. Although there was no difference in birthweight between the groups with a high or low Apgar score, the mortality rate of infants with a five-minute Apgar score of 0 to 3 was 79% compared to 22% in those with a score of 4 to 10. Over 50% of the infants developed hyaline membrane disease regardless of Apgar score. However, in the infants with a five-minute Apgar score of 0 to 3, the severity of respiratory insufficiency was increased as indicated by increased requirement for high inspired oxygen, and the need for intermittent positive pressure ventilation. The duration of stay in the neonatal intensive care area, and the total length of hospital stay of the 49 VLBW survivors were shorter in the group with higher two-minute and five-minute Apgar scores. Long-term morbidity cannot yet be ascertained. It is likely that prevention, or prompt detection, and appropriate management of perinatal asphyxia would produce a further decline in mortality as well as morbidity for VLBW infants.