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

Cognition, academic progress, behavior and self-concept at 14 years of very low birth weight children

The aim of this study was to compare cognition, academic progress, behavior, and self-concept children of very low birth weight (VLBW, birth weight < 1501 g) born in the period 1980 to 1982 with randomly selected children of normal birth weight (NBW, birth weight > 2,499 g). At 14 years of age, 130 (84.4%) of 154 VLBW and 42 (70.0%) of 60 NBW children were assessed. Ten VLBW children and one NBW child who had cerebral palsy were excluded. VLBW children scored at a significantly lower level on all three composite scales of the Wechsler Intelligence Scale for Children, 3rd Edition. VLBW children were also significantly disadvantaged on more specific cognitive processes, including tests of visual processing and visual memory and on subtests reflecting learning and problem solving. Only in arithmetic was a difference between the groups discerned on tests of achievement. Significantly more VLBW children were rated by teachers as socially rejected and by their parents as having learning problems at school. VLBW children had significantly reduced self-esteem. VLBW children had more cognitive, academic, and behavioral problems and lower self-esteem at 14 years of age than NBW control subjects.

Survival, cranial ultrasound and cerebral palsy in very low birthweight infants: 1980s versus 1990s

OBJECTIVE

To determine the changes in the rates of survival, cranial ultrasound abnormalities and cerebral palsy in very low birthweight (VLBW) (birthweight 500-1499 g) infants between the early 1980s and the early 1990s.

METHODOLOGY

A cohort study of consecutive VLBW live births in one tertiary perinatal hospital during two distinct eras was performed at The Royal Women's Hospital, Melbourne, a level-III perinatal centre. Consecutive VLBW infants born over the 18-month period from 1 October 1980 (n = 222), and over the 12-month period from 1 January 1992 (n = 202) were identified. The main outcome measures were the proportions of live births surviving to 5 years of age, rates of cranial ultrasound abnormalities, and rates of cerebral palsy at 5 years of age.

RESULTS

Over the 18 months from 1 October 1980, 68% (150/222) VLBW live births survived to 5 years of age. The survival rate rose substantially to 82% (165/202) during 1992 (odds ratio 2.1, 95% confidence interval 1.4-3.2). The survival rate increased over time more for those of 500-999 g birthweight than for those of 1000-1499 g birthweight. The rates of cerebroventricular haemorrhage (CVH) were similar inlive births and survivors from both eras, as were the rates of cerebral palsy (7.5% in 1980-82; 7.8% in 1992) in survivors seen at 5 years of age. The positive predictive value of CVH for cerebral palsy was low, but cystic periventricular leucomalacia was followed by cerebral palsy in seven of eight survivors from the 1992 cohort.

CONCLUSIONS

Despite the increasing survival rate with improvements in perinatal care, including more antenatal steroid therapy and the introduction of exogenous surfactant, the rates of CVH and of cerebral palsy in survivors have not diminished.

Hearing loss at the age of 5 years of children born preterm--a matter of definition

The effect of three common hearing impairment criteria on the prevalence of hearing loss was evaluated in 58 prospectively followed-up 5-year-old children born preterm at < or = 32 weeks of gestation. Audiological assessment was done as part of an extensive neurodevelopmental evaluation at the age of 5 years. With the criterion based on the classification of the World Health Organization (average threshold hearing level > 25 dB at frequencies of 0.5, 1 and 2 kHz, classified according to the less impaired side) there were two preterm children with mild hearing impairment. With Clark's criterion (unilateral average threshold hearing level > 15 dB at frequencies of 0.5, 1 and 2 kHz) eight children had slight hearing impairment; seven of these had conductive hearing problems. With the criterion of a single frequency-specific deficit > 15 dB for 0.25-4 kHz the number of hearing-impaired children was 28 out of 54 (51.9%), most of whom had conductive or unspecified hearing deficits. Moreover, of the four multiply handicapped, retarded children whose pure tone thresholds were not assessed monaurally, three would belong to the hearing-impaired group according to Clark's criterion and four according to the frequency-specific criterion.

Shortened hospital stay for low-birth-weight infants: nuts and bolts of a nursing intervention project

Prolonged hospitalization of low-birth-weight (LBW) newborns places them at increased risk for a number of medical and psychosocial complications. A randomized trial of earlier hospital discharge with community-based nursing follow-up and intervention was performed. Community-based, in-home, public-health nursing and homemaker services were provided on an individualized basis according to assessed need. A significantly higher number of nurse home visits and telephone contacts were made to the intervention families. One of the most identified needs of families of LBW infants was assistance with breastfeeding. More than half of the early discharge families needed and received homemaker assistance during the first 8 weeks after the newborn's discharge from hospital. Results showed that a community-based program that provided individualized support and education for families of LBW infants was safe, cost-effective, and had a positive influence on the home environment.

The long-term neurodevelopmental outcome for very low birthweight (VLBW) infants with 'dystonic' signs at 4 months of age

As very low birthweight (VLBW) infants are at a high risk of developmental handicap, it is important to establish predictors of long-term adverse outcome at an early age so that early intervention can be instituted. Longitudinal neurodevelopmental assessments were performed in 107 VLBW infants at 1, 4, 8 and 12 months corrected age. Eighteen were diagnosed as 'dystonic' at 4 months of age. This study compared the outcomes at 4 and 6 years for 15 of the 18 dystonic with 75 of the 89 non-dystonic VLBW infants, respectively. At 9 years of age, nine dystonic and 54 non-dystonic infants were assessed on the Rutter Behaviour Questionnaire. Dystonic children had a lower mean General Cognitive Index (GCI; P = 0.001) and a higher incidence of disability as measured by the Burns Neuro-Sensori-Motor Developmental Assessment Scale (P = 0.0005) and Kitchen disability grading (P = 0.001). Even if the minor neurological aberrations of the premature dystonia syndrome in VLBW infants abate by one year of life, these infants still constitute a high-risk group for subsequent neurodevelopmental disability and therefore require close observation and probably early intervention.

A neuropathologic analysis of neonatal deaths occurring in a single neonatal unit over a 20-year period

This study presents an overview of 2515 consecutive autopsies performed on newborn infants who died during the first 28 days of life at The Hospital for Sick Children, Toronto, during the period 1970-89. The infants were grouped into two categories according to their gestational age, then subdivided into groups of early (0-6 days) and late (7-28 days) neonatal death. Trends in the occurrence of neuropathologic observation were documented. For each 5-year period and each gestational group, the following diagnoses were recorded: hypoxic-ischemic neuronal changes, periventricular leukomalacia, infarction, kernicterus, meningitis, and hemorrhage (subependymal, parenchymal, choroidal). Over these 20 years, our results show that death in preterm infants decreased because of a drop in the incidence of subependymal hemorrhage/intraventricular hemorrhage, kernicterus, and meningitis but increased in term infants as a result of a higher frequency of hypoxic-ischemic neuronal necrosis and choroid plexus hemorrhage.

Neurodevelopmental outcome in very-low-birth-weight infants with or without periventricular haemorrhage and/or leucomalacia

The aim of the study was to verify the predictive value of ultrasound performed in the neonatal period for short-term neurodevelopmental prognosis in 122 preterm very-low-birth-weight infants followed-up at 36 months. Neuromotor development was favourable in 53 (87%) subjects with normal ultrasound findings and in 21 (81%) subjects presenting uncomplicated haemorrhage. However, sensory and/or cognitive sequelae developed in 13% and 19% of the two groups, respectively. Outcome was unfavourable in 14 (50%) of 28 patients with ultrasound findings of complicated cerebral haemorrhages and in 5 (71%) of those (7) with ultrasound findings of parenchymal lesions without haemorrhage. Neonatal ultrasound examination seems to be fundamental in predicting neuromotor, but not cognitive, outcome in very-low-birth-weight infants.

Improvement in outcome for very low birthweight children: apparent or real?

OBJECTIVE

To determine whether improvement in the survival rate of infants with a birthweight of less than 1501 g was accompanied by an increase in the rate of neurological impairment or disability among the survivors.

DESIGN, SETTING AND PATIENTS

Two cohorts of consecutive very low birthweight infants (birthweight less than 1501 g) in one tertiary perinatal centre were followed prospectively to eight years of age; for both cohorts, comparison groups of children of birthweight more than 1501 g were randomly selected from hospital births.

INTERVENTIONS

The first cohort was born before the introduction of assisted ventilation (1966-1970), the second after assisted ventilation was well established (1980-1982).

MAIN OUTCOME MEASURES

Comparisons between cohorts, at eight years of age, of the survival rates and the rates of severe sensorineural impairments and disabilities.

RESULTS

The survival rate for very low birthweight infants to eight years of age almost doubled between these cohorts, from 37.1% to 67.8% (odds ratio [OR], 3.4; 95% confidence interval [CI], 2.5-4.7; chi 2 = 57.6; P much less than 0.0001). The biggest gain was the increase in non-disabled survivors at eight years of age, from 52.6% in the first cohort to 80.8% in the second cohort (OR, 3.5; 95% CI, 2.2-5.7; chi 2 = 26.7; P less than 0.0001). Furthermore, the rate of severe disabilities in survivors fell substantially, from 13.6% to 4.1% (OR, 0.31; 95% CI, 0.14-0.69; chi 2 = 8.3; P less than 0.01). Of specific impairments, the rate of severe sensorineural deafness fell substantially (3.2% to 0%: OR, 0.14, 95% CI, 0.02-0.81; chi 2 = 4.8; P less than 0.05), as did the rate of severe intellectual impairment (13.0% to 2.7%: OR, 0.25; 95% CI, 0.11-0.57; chi 2 = 10.7; P less than 0.002). Only the rate of cerebral palsy increased, but not significantly (2.6% to 6.8%; OR, 2.6; 95% CI, 0.89-7.6; chi 2 = 3.0).

CONCLUSIONS

It has been possible to improve the survival rate of very low birthweight infants over time without increasing the number of severely disabled survivors. Whether the long-term outcome for these infants is continuing to improve with more recent advances in perinatal care remains to be determined.

Visual and auditory orienting responses in preterm infants: a comparison of three cohorts over time

Visual and auditory orienting responses were compared in three cohorts of preterm infants (N = 351) born between 1977 and 1987. The infants were divided into one group born between 25 and 34 weeks gestational age (n = 140) and one group born between 35 and 37 weeks gestational age (n = 211). Ratings were made of the infants' best orienting responses to a bull's-eye, rattle, bell, voice, and face plus voice combined. Analyses of covariance were computed to adjust for changes in perinatal variables between 1977 and 1987. For both groups, there were significant differences between cohorts on orienting to the bull's-eye, with a trend for the 25- to 34-week group on orienting to the rattle. Behavioral outcome for preterm infants has improved with changes in neonatal intensive care.

Changing trends in preterm childbirth

Progress in perinatal care has been accompanied recently by increasing numbers of induced premature deliveries because of fetal distress. This is confirmed by study of 26,796 consecutive births in the Caen Hospital Group between 1980 and 1987. Study of the fate of these children shows that this attitude has not led to any excess mortality when the share of the IPD before 32 weeks are regularly growing. This would imply that the prematurity rate is no longer a sufficiently accurate epidemiological index for the evaluation of prenatal care policies.

Early predictors of neurodevelopmental outcome at 12-36 months in very low-birthweight infants

We followed-up 71 preterm survivors, 36 (50.7%) females and 35 (49.3%) males, correlating the results of neurological examinations (NE) at 40 weeks of corrected gestational age (GA) and the cerebral ultrasound (US) diagnosis with the neurodevelopmental outcome at 12-36 months of life. All 34 children with normal NE at term presented adequate neurodevelopmental outcome; these subjects have a normal US scan or a scan that is pathologic for uncomplicated hemorrhage. Of the 6 children with pathologic NE, but a normal US, 3 (50%) had a normal outcome, while 2 (34%) had mild impairments and 1 (16%) grave neurodevelopmental deficits. Of the 31 subjects with pathologic NE and US, 12 (39%) showed a normal outcome, and 6 (19%) had mild and 13 (42%) grave neurodevelopmental deficits; signs of parenchymal lesions with or without periventricular hemorrhage were particularly correlated to US. We conclude that the combination of the results of NE at 40 weeks GA and brain US are useful in early neurodevelopmental prognosis in very low-birthweight infants.

Decreased disability rate among 3-year-old survivors weighing 501 to 1000 grams at birth and born to residents of a geographically defined region from 1981 to 1984 compared with 1977 to 1980

In this article we report the survival and morbidity rates for all live-born infants weighing 501 to 1000 gram at birth and born to residents of a defined geographic region from 1977 to 1980 (n = 255) compared with 1981 to 1984 (n = 266). During these periods, there were no changes in the proportion of infants delivered at the tertiary care center or community hospitals (171/84 vs 194/72); use of the tertiary care center increased only slightly, from 84% to 91%; and changes in neonatal management were mainly in improvements in diagnostic and monitoring techniques. When infants were grouped according to birth weights in 100 gm increments, survival improved significantly only for infants weighing between 501 and 600 gm at birth (2% vs 20% p less than 0.001). There were no differences in the overall survival rates to hospital discharge (46% vs 48%). The prevalence of neurosensory impairments was 24% in period 1 and 17% in period 2. There was a significant improvement in the proportion of infants considered to have disabilities by a functional classification assigned at 3 years corrected age (50% vs 27%, p less than 0.001), but only for infants weighing more than 800 gm at birth (49% vs 22%, p less than 0.001). Infants delivered at the community hospitals had a higher prevalence of neurosensory impairments compared with infants delivered at the tertiary care center (period 1, 35% vs 21%, not significant; period 2, 37% vs 14%, p less than 0.05). These data are encouraging; further efforts should be directed toward assessing which, if any, components of perinatal care are contributing to the improvement in morbidity rates.

Escalating consumption of nursery resources by extremely immature infants

Over a 9-year period at one tertiary perinatal centre there were 59,650 livebirths; although only 1,123 (1.9%) were born at or before 30 weeks' gestation, this small minority of infants consumed 71.7% of total patient-days in the neonatal intensive care unit (NICU) and an inordinate 87.9% of total patient-days of assisted ventilation. Infants born at 24 weeks required 39 times the patient-days of assisted ventilation and 19 times the patient-days in the NICU per survivor compared with those born at 30 weeks' gestation. In infants born before 28 weeks, for each week of decrease in gestation, survivors averaged an extra 13.0 days of assisted ventilation, stayed in the NICU 13.8 days more, and in hospital 14.9 days longer. Any therapy before 28 weeks which can keep infants safely in the uterus could save approximately 2 weeks of nursery resources for each extra intrauterine week and would be beneficial economically, even if it meant hospitalization of the mother over that time.

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

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