Extremely low birthweight infants at 3 years: a developmental profile

Retinopathy of prematurity and neurodevelopmental outcomes in preterm infants: A systematic review and meta-analysis

Background

Retinopathy of prematurity (ROP) and abnormal brain development share similar risk factors and mechanisms. There has been contrasting evidence on the association of ROP with adverse neurodevelopmental outcomes.

Objective

We analysed the association between ROP at levels of severity and treatment with all neurodevelopmental outcomes until adolescence.

Data source

We followed PRISMA guidelines and searched Medline and Embase between 1 August 1990 and 31 March 2022.

Study selection and participants

Randomised or quasi-randomised clinical trials and observational studies on preterm infants (<37 weeks) with ROP [type 1 or severe ROP, type 2 or milder ROP, laser or anti-vascular endothelial growth factor (VEGF) treated] were included.

Data extraction and synthesis

We included studies on ROP and any neurocognitive or neuropsychiatric outcomes.

Outcomes

The primary outcomes were as follows: cognitive composite scores evaluated between the ages of 18 and 48 months by the Bayley Scales of Infant and Toddler Development (BSID) or equivalent; neurodevelopmental impairment (NDI; moderate to severe NDI or severe NDI), cerebral palsy, cognitive impairment; and neuropsychiatric or behavioural problems. The secondary outcomes were as follows: motor and language composite scores evaluated between the ages of 18 and 48 months by BSID or equivalent; motor/language impairment; and moderate/severe NDI as defined by the authors.

Results

In preterm infants, "any ROP" was associated with an increased risk of cognitive impairment or intellectual disability [n = 83,506; odds ratio (OR): 2.56; 95% CI: 1.40-4.69; p = 0.002], cerebral palsy (n = 3,706; OR: 2.26; 95% CI: 1.72-2.96; p < 0.001), behavioural problems (n = 81,439; OR: 2.45; 95% CI: 1.03-5.83; p = 0.04), or NDI as defined by authors (n = 1,930; OR: 3.83; 95% CI: 1.61-9.12; p = 0.002). Type 1 or severe ROP increased the risk of cerebral palsy (OR: 2.19; 95% CI: 1.23-3.88; p = 0.07), cognitive impairment or intellectual disability (n = 5,167; OR: 3.56; 95% CI: 2.6-4.86; p < 0.001), and behavioural problems (n = 5,500; OR: 2.76; 95% CI: 2.11-3.60; p < 0.001) more than type 2 ROP at 18-24 months. Infants treated with anti-VEGF had higher odds of moderate cognitive impairment than the laser surgery group if adjusted data (gestational age, sex severe intraventricular haemorrhage, bronchopulmonary dysplasia, sepsis, surgical necrotising enterocolitis, and maternal education) were analysed [adjusted OR (aOR): 1.93; 95% CI: 1.23-3.03; p = 0.04], but not for cerebral palsy (aOR: 1.29; 95% CI: 0.65-2.56; p = 0.45). All outcomes were adjudged with a "very low" certainty of evidence.

Conclusion and relevance

Infants with "any ROP" had higher risks of cognitive impairment or intellectual disability, cerebral palsy, and behavioural problems. Anti-VEGF treatment increased the risk of moderate cognitive impairment. These results support the association of ROP and anti-VEGF treatment with adverse neurodevelopmental outcomes.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022326009.

Visual-motor and executive functions in children born preterm: the Bender Visual Motor Gestalt Test revisited

Visual-motor development and executive functions were investigated with the Bender Test at age 5½ years in 175 children born preterm and 125 full-term controls, within the longitudinal Stockholm Neonatal Project. Assessment also included WPPSI-R and NEPSY neuropsychological battery for ages 4-7 (Korkman, 1990). Bender protocols were scored according to Brannigan & Decker (2003), Koppitz (1963) and a complementary neuropsychological scoring system (ABC), aimed at executive functions and developed for this study. Bender results by all three scoring systems were strongly related to overall cognitive level (Performance IQ), in both groups. The preterm group displayed inferior visual-motor skills compared to controls also when controlling for IQ. The largest group differences were found on the ABC scoring, which shared unique variance with NEPSY tests of executive function. Multiple regression analyses showed that hyperactive behavior and inattention increased the risk for visual-motor deficits in children born preterm, whereas no added risk was seen among hyperactive term children. Gender differences favoring girls were strongest within the preterm group, presumably reflecting the specific vulnerability of preterm boys. The results indicate that preterm children develop a different neurobehavioral organization from children born at term, and that the Bender test with a neuropsychological scoring is a useful tool in developmental screening around school start.

Sensorimotor skills associated with motor dysfunction in children born extremely preterm

BACKGROUND

Children born prematurely, despite being free of intellectual and sensorineural deficits, are at risk of motor dysfunction.

AIM

To investigate the association of sensorimotor processing skills and Developmental Coordination Disorder (DCD) in "apparently normal" extreme preterm children.

STUDY DESIGN

In a matched case-control study, 50 preterm children born less than 29 weeks or birthweight <1000 g, with an IQ>85 and no identified sensorineural disability, were assessed at 8 years of age along with 50 gender and birth date matched classroom controls born at full term. A battery of sensorimotor tests was administered, which examined visual-motor, visual perception, tactile perception, kinaesthesia, and praxis.

RESULTS

For preterm children with DCD (n=21), significantly lower scores were found for the visual processing and praxis tests, with the exception of verbal command, in comparison to those 29 preterm children without DCD and term controls (median visual perception scores were 92, 96 and 108 respectively; design copying was 0.07, 0.46 and 0.95; constructive praxis was 0.09, 0.27 and 0.63; and sequencing praxis was 0.14, 0.73 and 0.96). There were no difference on the tactile sensitivity and kinaesthetic processing tests.

CONCLUSIONS

Preterm children with DCD have difficulty with visual processing tasks. Praxis or motor planning poses a particular challenge for them. Motor dysfunction in extremely preterm children was related to poorer visual processing and motor planning and may relate to a cognitive processing problem.

Neurodevelopmental outcome over time of preterm born children ≤750 g at birth

BACKGROUND

Extremely low birth weight (ELBW) infants are at risk of cognitive impairment and follow-up is therefore of major importance. The age at which their neurodevelopmental outcome (NDO) can reliably be predicted differs in the literature.

AIMS

To describe NDO at 2, 3.5 and 5.5 years in an ELBW cohort. To examine the value of NDO at 2 years corrected age (CA) for prediction of NDO at 3.5 and 5.5 years.

STUDY DESIGN

A retrospective cross-sectional and longitudinal cohort study.

SUBJECTS

101 children with a BW≤750 g, born between 1996 and 2005, who survived NICU admission and were included in a follow-up program.

OUTCOME MEASURES

NDO, measured with different tests for general development and intelligence, depending on age of assessment and classified as normal (Z-score≥-1), mildly delayed (-2≤Z-score<-1) or severely delayed (Z-score<-2).

RESULTS

At 2, 3.5 and 5.5 years 74.3, 82.2 and 76.2% had a normal NDO. A normal NDO at 2 years CA predicted a normal NDO at 3.5 and 5.5 years in 92% and 84% respectively. Of the children with a mildly or severely delayed NDO at 2 years CA the majority showed an improved NDO at 3.5 (69.2%) and 5.5 years (65.4%) respectively.

CONCLUSIONS

The majority of the children with a BW≤750 g had a normal NDO at all ages. A normal NDO at 2 years CA is a good predictor for normal outcome at 3.5 and 5.5 years, whereas a delayed NDO at 2 years CA is subject to change with the majority of the children showing a better NDO at 3.5 and 5.5 years.

A decade comparison of preterm motor performance at age 4

This was a prospective longitudinal study of two cohorts comprised of one full term and three premature infant groups born 10 years apart. Birth cohort, perinatal morbidity, and birth weight effects were investigated at age 4. Cohort 1 (1985-1989) had longer gestation, higher birth weight, and better Apgar scores than Cohort 2 (1996-1999), which had more intraventricular hemorrhage and bronchopulmonary dysplasia. Cohort and perinatal morbidity group, but not birth weight, predicted motor scores. Preterm Cohort 2 children had better oral motor, fine motor, and total motor scores, but lower visual motor integration scores than Cohort 1. Motor problems continue to affect preterm children at age 4, in particular those who experience perinatal morbidity, despite a decade of neonatal intensive care advancements.

Outcome of extremely low birth weight survivors at school age: the influence of perinatal parameters on neurodevelopment

Extremely low birth weight (ELBW) is associated with impaired neurodevelopmental outcome in infancy. Information on the long-term cognitive and neurological consequences of ELBW is scarce. We aimed to identify the perinatal and neonatal factors of ELBW infants associated with adverse cognitive and neurological outcome at school age. A regional cohort of 135 ELBW infants born between 1993 and 1998 was prospectively evaluated at 3, 6, 12, and 18 months postmenstrual age and at yearly intervals up to age 10 years. The comprehensive follow-up programme for high-risk infants included neurological examinations and psychometric evaluations. According to the overall results of these tests, children were classified as either being normal or having minor or major impairment. At a mean age of 8.4 (SD: 1.6) years, 43% of children had survived without any impairment. Minor impairment was diagnosed in 39% and major impairment in 18% of assessed children. The proportion of disabled school children rose with decreasing gestational age. The following neonatal complications were significant risk factors for developing major or minor impairment at school age: an increase in head circumference < 6 mm per week (OR 4.0, 95% CI: 1.1-14.8), parenteral nutrition > or = 6 weeks (OR 2.5, 95% CI: 1.1-6.0), and mechanical ventilation > 14 days (OR 2.3, 95% CI: 1.0-5.1). High-grade intraventricular haemorrhage (IVH) and/or PVL (OR 13.3, 95% CI: 4.0-44.9), neonatal seizures (OR 5.2, 95% CI: 1.2-22.4) and bowel perforation, and/or necrotizing enterocolitis (OR 4.4, 95% CI: 1.1-17.0) were significant risk factors for developing major impairment. In spite of the relatively large proportion of normal children, ELBW remains an important risk factor for neurodevelopmental impairment at school age. Thus, measures to prevent complications such as necrotizing enterocolitis, cerebral haemorrhage, and undernutrition remain important goals for neonatal intensive care.

Eye-hand co-ordination skills in very preterm infants <29 weeks gestation at 3 years: Effects of preterm birth and retinopathy of prematurity

INTRODUCTION

Preterm infants are known to have low gross motor and fine motor skills. We questioned whether poor eye-hand coordination skills are associated with moderate to severe stages of Retinopathy of Prematurity (ROP).

AIMS

The aim of this study was to examine development, with specific reference to eye-hand coordination skills, among preterm infants <29 weeks gestation with different stages of ROP at 3 years of age.

METHODS AND MATERIALS

Fifteen preterm infants (<29 weeks gestation) who developed Stage 3 ROP were matched for gestation, birthweight and gender with infants who developed Stage 2 and Stage 1/no ROP. Developmental (Griffiths Mental Development Scales and Peabody Developmental Motor Scales) and ophthalmic assessments in the 3 matched groups of 15 were performed at 3 years of age.

RESULTS

1) Whilst the eye-hand coordination scores and Peabody fine motor scores were lower in the Stage 3 ROP group, they were not significantly lower than the other ROP groups. 2) Locomotor, Peabody gross motor skills and hearing and speech were significantly lower in the infants with Stage 3 ROP. The other developmental domains were not significantly different to the severe ROP group. 3) All 3 groups (of preterm infants) had lower eye-hand coordination and Peabody fine motor scores compared to test norms. 4) There were 8 of 15 infants with Stage 3 ROP who developed moderate visual problems by 3 years of age.

CONCLUSION

In preterm infants, low eye-hand coordination/fine motor scores are likely to be due to their extreme prematurity.

The EPICure study: associations and antecedents of neurological and developmental disability at 30 months of age following extremely preterm birth

AIMS

To describe perinatal factors associated with later morbidity among extremely preterm children at 30 months of age corrected for prematurity.

POPULATION

Of 308 surviving children born at <or=25 weeks gestation in the United Kingdom and Ireland from March to December 1995, 283 (92%) were evaluated at 30 months of age corrected for prematurity.

METHODS

Cerebral palsy, severe motor disability, and Bayley scores were used as dependent variables in sequential multiple regression analyses to identify factors associated with adverse outcomes.

RESULTS

Adverse outcomes were consistently more common in boys. Factors related to perinatal illness, ultrasound evidence of brain injury, and treatment (particularly postnatal steroids) were associated with adverse motor outcomes (cerebral palsy, disability or Bayley psychomotor development index). Increasing duration of postnatal steroid treatment was associated with poor motor outcomes. A score was developed for severe motor disability with good negative predictive value. In contrast, mental development was associated with a broader range of factors: ethnic group, maternal educational level, the use of antenatal steroids, and prolonged rupture of membranes in addition to chronic lung disease.

CONCLUSION

Male sex is a pervasive risk factor for poor outcome at extremely low gestations. Avoidable or effective treatment factors are identified, which may indicate the potential for improving outcome.

Temporal and demographic trends in cerebral palsy--fact and fiction

The rate of cerebral palsy has not decreased in developed countries over the past 30 years, despite the widespread use of electronic fetal heart rate monitoring and a 5-fold increase in the cesarean delivery rate over the same period of time. However, neonatal survival has improved during these decades. These observations have lead to the hypothesis that increased survival of premature, neurologically impaired infants may have masked an actual reduction in cerebral palsy among term infants as a result of the use of electronic monitoring and the avoidance of intrapartum asphyxia. A review of the medical literature, as well as a demographic analysis of term and preterm birth rates in the United States, refutes this hypothesis on four grounds. First, cerebral palsy prevalence has been separately analyzed in term infants and shows no change over 30 years. Second, the prevalence of cerebral palsy is the same or lower in underdeveloped countries than in developed nations; in the former, the availability of emergency cesarean delivery based on electronic monitor data is limited or absent. Third, the increase in prevalence of cerebral palsy among low-birth-weight infants and the increase in cesarean sections based on presumed fetal distress were not simultaneous events-the former preceded the latter by a decade. Improved neonatal survival since the 1980s has been associated with a stable or decreasing rate of neurologic impairment and thus could not have obscured improvement from reduced term asphyxia. Finally, compared with the number of infants born by cesarean section for fetal distress, there are simply not enough infants born in the most vulnerable weight groups to make any impact on even a minimal improvement of outcome in the group delivered by cesarean section for presumed fetal distress. Except in rare instances, cerebral palsy is a developmental event that is unpreventable given our current state of technology.

Cognitive development at 5.5 years of children with chronic lung disease of prematurity

BACKGROUND

Preterm infants with chronic lung disease (CLD) had impaired cognitive development and poorer eye-hand coordination at 10 months of age.

AIMS

To study whether this effect of CLD persisted until school age and whether the severity of CLD affected outcome.

METHOD

Cognition and visual-motor skills were examined (Wechsler preschool and primary scale of intelligence, and tests from the Nepsy scale) in 60 very preterm children, without intraventricular haemorrhage or periventricular leucomalacia, at 5.5 years of age. Thirty two children suffered from CLD and 28 were controls.

RESULTS

The groups did not differ significantly in cognitive outcome. Children with CLD and controls attained a full scale intelligence quotient (IQ) of 94.4 and 99.1, a verbal IQ of 99.6 and 101.5, and a performance IQ of 90.9 and 96.7 respectively. Similarly, no difference was found in tests of eye-hand control. However, the children with the most severe form of CLD had significantly lower performance (84.8) and full scale(87.6) IQs and worse visual-motor performance than the controls. CLD grade III, together with the need for glasses or lenses, had a significant impact on the explained variance.

CONCLUSIONS

At school age, children born very preterm and who experienced severe CLD had deficits in cognition, visual-motor perception, and performance. The findings suggest a need to consider intervention programmes for such infants.

Longitudinal motor development of "apparently normal" high-risk infants at 18 months, 3 and 5 years

BACKGROUND

Motor development appears to be more affected by premature birth than other developmental domains, however few studies have specifically investigated the development of gross and fine motor skills in this population.

AIM

To examine longitudinal motor development in a group of "apparently normal" high-risk infants.

SETTING

Developmental follow-up clinic in a perinatal centre.

STUDY DESIGN

Longitudinal observational cohort study.

SUBJECTS

Fifty-eight infants born less than 29 weeks gestation and/or 1000 g and without disabilities detected at 12 months.

OUTCOME MEASURES

Longitudinal gross and fine motor skills at 18 months, 3 and 5 years using the Peabody Developmental Motor Scales. The HOME scale provided information of the home environment as a stimulus for development.

RESULTS

A large proportion (54% at 18 months, 47% at 3 years and 64% at 5 years) of children continued to have fine motor deficits from 18 months to 5 years. The proportion of infants with gross motor deficits significantly increased over this period (14%, 33% and 81%, p<0.001), particularly for the 'micropreemies' (born <750 g). In multivariate analyses, gross motor development was positively influenced by the quality of the home environment.

CONCLUSIONS

A large proportion of high-risk infants continued to have fine motor deficits, reflecting an underlying problem with fine motor skills. The proportion of infants with gross motor deficits significantly increased, as test demands became more challenging. In addition, the development of gross and fine motor skills appears to be influenced differently by the home environment.

Factors influencing maternal mental health and family functioning during the low birthweight infant's first year of life

The care of the low birthweight (LBW) infant poses a considerable challenge to the entire family, especially to the infant's mother, who is typically the primary caregiver. The purpose of this study was to determine the effects of the infant's medical vulnerability and the psychosocial context of caregiving on the mental health of mothers who care for these infants and the functioning of their families. Results indicate that the degree to which an infant was unresponsive and the severity of the baby's physical health problems during the first year were associated with more mental health problems for the mother. Lack of infant responsiveness was also related to less cohesion and adaptability for the family as a whole. Family cohesion, presence of a partner, emotional support, and a mother's satisfaction with her family all contributed to her better mental health. In contrast, her life stress and the family's use of internally focused coping strategies contributed to worse mental health outcomes. Findings indicate the need for nursing interventions to support the mother and family in developing effective approaches to care for their LBW infant and for one another.

Early motor and mental development in very preterm infants with chronic lung disease

BACKGROUND

The increased incidence of neurological deviations in preterm infants with chronic lung disease (CLD) has been linked to severe brain haemorrhage (intraventricular haemorrhage (IVH)) and periventricular leucomalacia (PVL) rather than to CLD per se.

AIM

To evaluate whether CLD without concomitant brain lesions constitutes a risk factor for adverse developmental outcome.

METHOD

Forty three very low birthweight infants with CLD, but without IVH or PVL, and 43 very low birthweight infants without CLD, IVH, or PVL were evaluated at 5 and 10 months of corrected age using the movement assessment of infants (MAI) scale. The Griffiths' developmental test was carried out at 10 months of age.

RESULTS

The overall motor assessments (MAI) in infants with CLD and controls were not significantly different. However, differences were observed in the execution of volitional movements (MAI), the total sum, hand and eye coordination, and perception and intelligence (measured by the performance scale of the Griffiths' test).

CONCLUSIONS

CLD has a deleterious effect on the control of hand and eye coordination and on perception and intelligence. These results thus re-emphasise the necessity for careful neurodevelopmental follow up of infants with CLD whether or not they suffered IVH or PVL.

Visual-motor function of very low birth weight and full-term children at 3 1/2 to 4 years of age

Improvements in perinatal and neonatal management have not only led to a higher survival rate of very low birth weight infants (VLBW; < or = 1,500 g or < 32 weeks gestational age), but also to a better outcome of these children. However the percentage of VLBW children who need special education because of later school problems remains high even in children considered neurologically normal during infancy. We assessed 40 VLBW children and 83 healthy full-term children at age 3 to 4 years by means of a simple and short test for visual-motor deficits. The test included the copying and cutting-out of geometric shapes, the building of models, the recognition of colours and the observation of the concentration and cooperation during the test. All VLBW children had had a good perinatal outcome and had been considered neurologically normal at one year of age. Most VLBW children scored within 1 standard deviation (S.D.) of the test mean, but on average the VLBW children scored significantly lower than the full-term infants in the copying of figures, the cutting-out of geometric forms, the building of models and in the overall concentration and cooperation during the test. Children who attended a nursery school achieved significantly better test results. Girls tended to have better results, but this was not statistically significant. Social factors and age had a significantly greater impact on results than perinatal factors. In summary, VLBW children scored significantly less in almost every test item compared to their term peers. Our test battery could serve as a short introductory test to screen for deficits in visual-motor skills, especially in VLBW children.

Visual-motor, visual-perceptual, and fine motor outcomes in very-low-birthweight children at 5 years

The prevalence and severity of visual-motor deficits and the relation of visual-motor function to visual perception and fine motor skills was examined in a group of 83 neurologically and intellectually normal (IQ >84) very-low-birthweight (VLBW) children at age 5. Fifteen children (17%) had below average visual motor scores (<1SD below mean). While relatively few children (N=9) had below average scores in visual perception (11%), 58 (71%) had below average scores for fine motor skills. Nineteen (23%) were considered impaired (<1.5SD); of these, eight were severely impaired (<2SD). Fine motor scores were significantly lower in children who had been born <28 weeks' gestation, with hyaline membrane disease, or had required a longer period of ventilation. There was significant correlation between visual-motor and fine motor scores (r = 0.50, P < 0.001) and between visual-motor and visual perception scores (r = 0.42, P < 0.001). The implications of these findings and management of these 'normal' children need further research. Previous reports of visual-motor dysfunction in school-age VLBW children could be related to fine motor difficulties.

Psychomotor development at 10 months as related to neonatal health status: the Stockholm Neonatal Project

The psychomotor development of 171 preterm very-low-birthweight (VLBW) infants (birthweight < or = 1500 g) at 10 months of corrected age was assessed by the Griffiths' Mental Developmental Scale. The developmental score was related to the prenatal and obstetric risk factors and to the neonatal health status of each infant. These results, in turn, were compared to findings for a reference group of full-term infants. This analysis revealed that prolonged ventilator treatment, patent ductus arteriosus, bronchopulmonary dysplasia, brain haemorrhage with ventricle dilatation, white matter lesions, low birthweight and low gestational age influenced psychomotor development in an unfavourable manner. Multiple regression analysis confirmed most of these correlations. Preterm birth per se (when children with risk factors were excluded) in general had no significant effect on psychomotor development. However, the early development of preterm infants with several neonatal risk factors was adversely affected.

Prevalence and aetiology of neurological impairment in extremely low birthweight infants

OBJECTIVE

To determine the prevalence and perinatal predictors of cerebral palsy, intellectual impairment, visual impairment and deafness in a cohort of extremely low birthweight (ELBW) infants at two years of age.

METHODOLOGY

The study population comprised 199 of the 224 (89%) ELBW infants managed at the Mater's Mothers Hospital, Brisbane, between July 1977 and February 1990 and who survived to two years. The prevalence of cerebral palsy, intellectual impairment, blindness and deafness was measured by clinical,psychometric and audiological assessment and the association with 24 risk factors examined.

RESULTS

Cerebral palsy occurred in 20 children (10%). Risk of cerebral palsy was associated with ventricular dilatation, intraventricular haemorrhage, necrotizing enterocolitis and multiple birth, though only ventricular dilatation (OR 4.41; 95% CI 1.32-14.8) remained significant in the adjusted analysis. Intellectual impairment occurred in 20 children (10%) and was independently associated with ventricular dilatation (OR 15.0; 95% CI 2.2-102.8), ventilation F(i)(2) > 80% (OR 3.4; 95% CI 1.01-11.5), vaginal delivery (OR 3.5; 95% Cl 1.09-11.4) and male sex (OR 6.1; 95% Cl 1.67-22.3). No perinatal predictor was statistically associated with risk of deafness. Retinopathy of prematurity (OR 36.9; 95% Cl 2.8-495.5) was associated with risk of later visual impairment.

CONCLUSIONS

Intellectual impairment was associated with a broad range of perinatal variables. Cerebral palsy was associated with fewer variables, all of which were also associated with intellectual impairment. Neurologic injury was associated with male sex and multiple birth, which are not biological insults themselves, but may be markers of susceptibility to injury.

Predictive value of the Griffiths assessment in extremely low birthweight infants

OBJECTIVE

To assess the relationship between the Griffiths Mental Development Scales at 1 and 3 years and the Stanford-Binet Intelligence Scale (S-B) and Beery Test of Visual-Motor Integration (VMI) at 5 years in extremely low birthweight (ELBW) children.

METHODOLOGY

Prospective study of 45 ELBW infants, without severe neurosensory impairment, cared for in a single Level III neonatal intensive care unit.

RESULTS

At 5 years, 36 (80%) children were of average intelligence, 8 (18%) had borderline intelligence and one was mentally retarded. The Griffiths general quotient (GQ) at 1 year had a weak correlation with the 5 year IQ (corr. coeff. = 0.47), with only 17% of children with a GQ < -1 s.d. at 1 year receiving an IQ < -1 s.d. at 5 years. In contrast, the Griffiths GQ at 3 years correlated strongly with 5 year IQ (corr. coeff. = 0.78). Among those children with a 3 year GQ < -1 s.d., 67% had a 5 year IQ < -1 s.d. and all had a 5 year 1Q < 89. The 3 year hearing and speech subscale correlated strongly with the 5 year S-B verbal comprehension factor (corr. coeff. = 0.753) and the 3 year combined eye/hand co-ordination/performance quotient had a moderate correlation with the S-B non-verbal reasoning factor (corr. coeff. = 0.597) and with the Beery VMI (corr. coeff. = 0.49).

CONCLUSIONS

The 3 year Griffiths GQ is a good predictor of 5 year S-B IQ in ELBW children and can be used to identify children who may benefit from intervention prior to school entry.

Changing patterns of survival and outcome at 4 years of children who weighted 500-999 g at birth

OBJECTIVE

To evaluate the impact of changing perinatal practices on survival rates and 4 year neurodevelopmental outcome for infants of birthweight 500-999 g.

METHODOLOGY

The study was a tertiary hospital-based prospective cohort study that compared survival, impairment and handicap rates between two eras, July 1977 to December 1982 (era 1) and January 1983 to June 1988 (era 2). All 348 live, inborn infants and 49 outborn infants of birthweight 500-999 g were prospectively enrolled in a study of survival and outcome. Rates of survival, neurodevelopmental impairment and functional handicap at 4 years were compared between eras. Perinatal risk factors for handicap were also compared between eras.

RESULTS

Four year survival rates for inborn infants 500-999 g improved from 32.6% in era 1 to 49.2% in era 2 (OR 2.1, 95% CI 1.26-3.48) but for outborn infants the improvement between 31.8% and 53.6% was not significant. There were significant improvements in survival for inborn infants in birthweights 800-899 g and 900-999 g between study periods. The rates of functional handicap between the first and second eras (mild 10 vs 7%; severe or multiply severe 14 vs 16%) were not significantly different. Although the rate of cerebral palsy increased from 0 to 12% (P < 0.01) other rates of impairment such as blindness 0 vs 3%, deafness 2 vs 2% and developmental delay 12 vs 11% did not change. The chance of a survivor being free of handicap remained unchanged at 78% and 76% for the two eras, respectively. Although the absolute number of intact survivors more than doubled (41 vs 83) so too did the number of severe or multiply severe handicapped survivors (7 vs 17). Multivariate logistic regression analysis for the entire study cohort revealed male gender, multiple birth, prolonged mechanical ventilation and cerebral ventricular dilatation but not birthweight or gestational age to be independently associated with severe or multiply severe handicap.

CONCLUSIONS

The advances in neonatal intensive care for extremely low birthweight infants between July 1977 and December 1982 and January 1983-June 1988 resulted in an increased number of non-disabled survivors but had no impact on incidence of severe disability. The application of prediction of mortality or severe handicap to clinical practice has the potential to reduce the proportion and absolute number of severely handicapped survivors.

Risk factors for sensorineural hearing loss in extremely premature infants

OBJECTIVE

To identify potentially preventable risk factors for sensorineural hearing loss (SNHL) in extremely premature infants.

METHODOLOGY

A case control study of survivors with gestational age (GA) < 28 weeks or birthweight (BW) < 1000 g using data collected prospectively in our Neonatal Intensive Care Unit database. Each subject with bilateral SNHL > 40 dB was matched according to GA, BW and sex with two controls who had neither sensorineural nor conductive hearing loss.

RESULTS

Infants with SNHL had increased mean (+/- s.d.) days ventilated (53 +/- 21 vs 37 +/- 23 days, P = 0.006) and in oxygen (107 +/- 44 vs 69 +/- 28 days, P = 0.02) compared with controls. The risk for SNHL was increased for infants who spent > 90 days in oxygen (OR 4.0 [95% CI 1.1-15.6]), had maximum FiO2 > 0.90 (5.6 [1.2-26.9]), minimum plasma Na < 125 mmol/L (5.6 [1.1-27.8] or maximum pH > 7.60 (5.6 [1.1-89.0]). Neither maximum serum bilirubin nor exposure to ototoxic drugs was associated with SNHL.

CONCLUSIONS

Avoidance of severe hyponatraemia and extreme alkalosis, as well as use of surfactant to minimize the severity of hyaline membrane disease, may result in a decreased incidence of SNHL in extremely premature infants.

Extremely low birth weight and control infants at 2 years corrected age: a comparison of intellectual abilities, motor performance, growth and health

A 2-year cohort of 63 surviving extremely low birth weight (ELBW) infants was prospectively studied and 60 of these infants, together with 44 normal birth weight control infants, were assessed at 2 years of age for intellectual abilities, motor skills, growth and health. The total ELBW group differed significantly from controls on overall Griffiths developmental quotient (99.3 vs. 103.8 P = 0.02) and in the personal/social subscale (100.7 vs. 106.7 P = 0.01). A subset of 43 of the ELBW infants was identified as low risk at discharge. No statistically significant differences were present between the low risk ELBW subset and controls in intellectual abilities though both the total ELBW group and the low risk ELBW subset differed from controls in fine and gross motor abilities, and in weight at 2 years. The total ELBW group also experienced more frequent ill health and hospital readmission.