Low birthweight: a 10-year outcome study of the continuum of reproductive casualty

Pre-Academic Skill Development in Children Who Were Full-Term Low-Birthweight Infants: Pilot Data

This investigation assessed pre-academic skill performance in 19 preschool-aged children with no significant disability who had been full-term low-birthweight infants. Subjects were drawn from a 1988 cohort of intensive-care nursery graduates. Mean birthweight was 2239 g, and mean gestational age was 36.7 weeks. The Miller Assessment for Preschoolers (MAP) was used to measure pre-academic skill development. The MAP scores include a total score and five index scores: foundations, coordination, verbal, nonverbal, and complex tasks. Percentile scores derived from MAP testing were analyzed to determine if scores in the study population fell below the 25th percentile, indicating risk for delays in pre-academic skill performance and warranting tracking services. Results indicated that, as a group, this full-term low-birthweight sample of preschool-aged children had adequate overall pre-academic skill development. However, closer examination of MAP indices suggests the presence of some difficulties. Forty-seven percent of the sample fell below the 25th percentile risk cut-off in the Coordination Index. Also of potential concern were findings from the Verbal Index in which 21.2% of the sample scored at risk. Parental concerns about the child's development often correctly predicted deficits in appropriate MAP indices. This finding, along with findings from the data analysis, suggests that a portion of this population of children continues to be at risk for developmental difficulties. Evaluating pre-kindergarten readiness, using both formal evaluation tools and parental input, may be important for identifying children from this “at-risk” group who may be experiencing pre-academic difficulties. Further investigation with a broader sample is recommended.

Pattern visual evoked potential performance in preterm preschoolers with average intelligence quotients

BACKGROUND

Preterm infants are more likely to develop visual perceptual and visual-motor impairments. Visual perceptual deficiencies may contribute to significant difficulties in daily life, but few reports are available relating electrophysiological assessment of the visual system to spatial information problems in premature preschoolers with average intelligence quotients.

AIM

This study was designed to investigate preterm preschoolers' responses to various spatial frequencies of pattern reversal visual evoked potential (PRVEP) and compare them to normal children.

DESIGN

Participants were 20 very low birth weight (VLBW), 41 low birth weight (LBW) and 41 normal children who were 4 to 6 years old and were free from major disability and developmentally appropriate for gestational age at birth. They were evaluated using the Chinese population adaptation of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) and recorded PRVEP at five levels of spatial frequency (checkerboard pattern (check) sizes of 108', 54', 27', 13' and 7') using a VikingQuest-IV neuroelectrophysiological device (Nicolet, Madison, WI, USA).

RESULTS

Compared with normal children, the LBW and VLBW groups had significantly lower level in the tests of verbal, performance and overall intelligence quotients, particularly in performance, although the levels were within the average range. The PRVEP P100 wave latencies were significantly prolonged at all five degrees of spatial frequency in the VLBW group compared with the controls, while showing delay in the LBW with 13' and 7' check size. In the meanwhile, the amplitudes of P100 at all five spatial frequencies were significantly smaller in the VLBW and LBW groups than in the normal children. And VLBW group had even lower P100 amplitudes than the LBW group.

CONCLUSIONS

Preterm preschoolers with average cognition capability are at risk of defect in visual-spatial perception, especially when they are confronted with more complicated information. PRVEP may provide an objective and convenient measurement in detecting the problem of visual perception in children.

Flash visual evoked potentials at 2-year-old infants with different birth weights

BACKGROUND

Increased prevalence of visual impairments has been reported in preterm populations. However, it remains unclear about the long-term visual electrophysiological outcomes and their association with visual cognitive functions in premature infants. We investigated visual electrophysiological outcome of 2-year-old infants of different birth weights by flash visual evoked potentials (FVEPs) in order to explore the correlation between visual cognitive functions and FVEPs and to assess the application of FVEPs in evaluating the visual capability of an infant.

METHODS

The FVEPs of 77 infants, including 25 very low birth weight (VLBW) premature infants, 16 low birth weight (LBW) premature infants and 36 full-term infants, were tested with a visual electrophysiological testing device. Neuromotor development was assessed with the Bayley Scales of Infant Development, Second Edition (BSID-II). The visual cognitive functions were evaluated by scoring the proportion passed of 12 items chosen from the BSID-II for infants at 23 to 25 months of age.

RESULTS

The second prominent positive wave (P2) was the major component presented in all three groups. The mean latency of P2 in the VLBW, LBW and full-term groups was 149.65+/-23.79 ms, 129.39+/-8.70 ms, and 126.14+/-7.73 ms respectively. There was no significant difference in mean latency of P2 wave between the LBW and full-term groups; the mean latency of the P2 wave in the VLBW group was delayed more significantly than those of the other two groups. The difference in amplitude of the P2 peak to the preceding N2 peak (N2P2) between the three groups was not statistically significant. The latency of the P2 main wave was negatively correlated with mental developmental index (MDI) (r'(MDI) = -0.35) and visual cognitive capability (r'(visual capability) = -0.21).

CONCLUSIONS

The latency of the P2 main wave on FVEPs was delayed more significantly in premature infants than in full-term infants at 2 years of corrected age. The visual functional development was delayed in premature infants, especially in VLBW infants (gestational age <32 weeks). The FVEPs were reported low but there were statistically significant correlations between measures of visual cognition and P2 peak latency. As a noninvasive and convenient method, FVEPs are useful in assessing certain aspects of an infant's visual development and visual function.

Cerebral palsy for the pediatric eye care team part 1: epidemiology, pathogenesis, and systemic findings

Cerebral palsy (CP) is a term used to describe a spectrum of neurological deficits resulting from damage to the immature brain. It is a chronic, nonprogressive motor disorder that affects posture, muscle tone, and movement, and therefore commonly results in ophthalmologic abnormalities such as strabismus and eye movement disorders. A basic understanding of CP and its effects will assist the clinician in the diagnosis, prognosis, and management of associated ophthalmologic disorders. This first, in a series of three articles, reviews the definition, epidemiology, pathogenesis, and classification of CP, as well as current management of the postural and motor effects. Results include a retrospective review of 131 consecutive cases of cerebral palsy referred to the Department of Ophthalmology by the Cerebral Palsy Center at the St. Louis Children's Hospital. The second article in the series will present the frequency, diagnosis, and management of the ocular motor deficits associated with CP. Article three will discuss the evaluation of visual acuity, management of decreased vision, and the frequency and type of binocular vision deficits associated with CP.

Early preventive attachment-oriented psychotherapeutic intervention program with parents of a very low birthweight premature infant: results of attachment and neurological development

The birth of a very small preterm infant (< or = 1500 grams) can be a traumatizing experience for many parents. A developmental risk model is presented that is the background to an early attachment-oriented preventive psychotherapeutic intervention. This comprehensive parent-centered intervention program is composed of supportive group psychotherapy, attachment-oriented focal individual psychotherapy, a home visit and video-based sensitivity training. The intervention aims at improving parental coping, the process of attachment and parent-infant interaction. In a prospective longitudinal design mothers were randomly assigned to a control (N = 44) and an intervention group (N = 43) after preterm delivery. Results show that the percentage of secure (control vs. intervention group: 77.8% vs. 59.4%) and insecure (control vs. intervention group: 8.3% vs. 31.3% avoidant, 13.9% vs. 9.4% ambivalent) attachment quality in high-risk preterm infants is comparable to results from studies with term infants. There was no significant statistical difference in terms of quality of attachment of the preterm infants between the control group and the intervention group. However, only in the control group, impaired neurological development corresponded significantly with an insecure quality of attachment, but not in the intervention group, although there were significantly more neurologically impaired infants in the intervention group. This result is discussed as an effect of the intervention program.

Patterns of motor disability in very preterm children

Motor development in very preterm children differs in several important ways from that of children born at full term. Variability is common, although the anatomic and physiologic bases for that variability are often poorly understood. Motor patterns over the first postnatal year may depend on behaviours learned during often long periods of neonatal intensive care. The normal pattern of development may be modified by disturbances of brain function caused both by the interruption of normal brain maturation ex-utero and the superimposition of focal brain injuries following very preterm birth. Abnormal patterns of development over the first year may evolve into clear neuromotor patterns of cerebral palsy or resolve, as "transient dystonias." Cerebral palsy is associated with identified patterns of brain injury secondary to ischaemic or haemorrhagic lesions, perhaps modified by activation of inflammatory cytokines. Cerebral palsy rates have not fallen as might be expected over the past 10 years as survival has improved, perhaps because of increasing survival at low gestations, which is associated with the highest prevalence of cerebral palsy. Children who escape cerebral palsy are also at risk of motor impairments during the school years. The relationship of these impairments to perinatal factors or to neurological progress over the first postnatal year is debated. Neuromotor abnormalities are the most frequent of the "hidden disabilities" among ex-preterm children and are thus frequently associated with poorer cognitive ability and attention deficit disorders. Interventions to prevent cerebral palsy or to reduce these late disabilities in very preterm children are needed.

The discrepancy between maturation of visual-evoked potentials and cognitive outcome at five years in very preterm infants with and without hemodynamic signs of fetal brain-sparing

OBJECTIVE

After intrauterine growth restriction we found at the age of 6 months an acceleration of neurophysiologic maturation. However, at later ages impaired cognitive outcome has been reported. Therefore, we investigated in children with and without fetal hemodynamic adaptation to intrauterine growth restriction whether the accelerated neurophysiologic maturation in infancy might be associated with impaired cognitive outcome at preschool age.

DESIGN

At 5 years of age cognitive function was assessed using the Revision of the Amsterdam Children's Intelligence Test in 73 preterm infants (26-33 weeks) who were prospectively followed from the antenatal period up to the age of 5 years. Maternal educational level was used as a background variable to estimate the confounding effects of socioeconomic status on cognitive function. Fetal Doppler studies were performed and the umbilical artery pulsatility index (PI) divided by the middle cerebral artery PI ratio (U/C ratio) was calculated. A U/C ratio >0.725 was considered as an indication of fetal cerebral hemodynamic adaptation to a compromised placental perfusion, ie, fetal brain-sparing. Visual-evoked potentials (VEPs) were recorded at 6 months and 1 year of age. In addition, data on neurologic status at 3 years were available.

RESULTS

Mean IQ score was significantly lower for children born with a raised U/C ratio (87 +/- 16) compared with children with a normal U/C ratio (96 +/- 17). VEP latencies decreased significantly in infants with a normal U/C ratio, whereas no decrease was found in infants with a raised U/C ratio. Variables contributing significantly to the variance of cognitive function were: U/C group, VEP latency maturation, level of maternal education, and neurodevelopmental outcome at 3 years. The linear regression model explained 33% of the variance in cognitive function.

CONCLUSIONS

Both being born with a raised U/C ratio and an acceleration of VEP latencies are negatively associated with cognitive outcome at 5 years of age. Fetal brain-sparing, although a seemingly beneficial adaptive mechanism for intact neurologic survival, is, however, later associated with a poorer cognitive outcome.

The impact of low birth weight, perinatal conditions, and sociodemographic factors on educational outcome in kindergarten

OBJECTIVE

To assess the relative effects and the impact of perinatal and sociodemographic risk factors on long-term morbidity within a total birth population in Florida.

METHODS

School records for 339 171 children entering kindergarten in Florida public schools in the 1992-1993, 1993-1994, or 1994-1995 academic years were matched with Florida birth records from 1985 to 1990. Effects on long-term morbidity were assessed through a multivariate analysis of an educational outcome variable, defined as placement into 9 mutually exclusive categories in kindergarten. Of those categories, 7 were special education (SE) classifications determined by statewide standardized eligibility criteria, 1 was academic problems, and the reference category was regular classroom. Generalized logistic regression was used to simultaneously estimate the odds of placement in SE and academic problems. The impact of all risk factors was assessed via estimated attributable excess/deficit numbers, based on the multivariate analysis.

RESULTS

Educational outcome was significantly influenced by both perinatal and sociodemographic factors. Perinatal factors had greater adverse effects on the most severe SE types, with birth weight <1000 g having the greatest effect. Sociodemographic predictors had greater effects on the mild educational disabilities. Because of their greater prevalence, the impact attributable to each of the factors (poverty, male gender, low maternal education, or non-white race) was between 5 and 10 times greater than that of low birth weight and >10 times greater than that of very low birth weight, presence of a congenital anomaly, or prenatal care.

CONCLUSIONS

Results are consistent with the hypothesis that adverse perinatal conditions result in severe educational disabilities, whereas less severe outcomes are influenced by sociodemographic factors. Overall, sociodemographic factors have a greater total impact on adverse educational outcomes than perinatal factors.

Psychological findings in preterm children related to neurologic status and magnetic resonance imaging

OBJECTIVE

Preterm children experience learning disabilities more often than full-term children, but detailed information on their neuropsychological and neurologic determinants is lacking. We therefore examined these problems more closely and also studied if clinical neurologic examination and/or magnetic resonance imaging (MRI) can be used as tools to screen the preterm children at risk for these problems.

METHODS

In a population-based study, the psychological performance of 42 preterm children with a birth weight <1750 g and of their matched controls was assessed at 8 years of age and the findings were then related to clinical neurologic examination and MRI. Learning disabilities of these children, reported by the teachers, were also studied.

RESULTS

The cognitive ability of the preterm children, although in the normal range, was significantly lower than that of the control children. They performed particularly poorly in tasks requiring spatial and visuoperceptual abilities, which were associated with the finding of periventricular leukomalacia in MRI, especially with posterior ventricular enlargement. The preterm children with minor neurodevelopmental dysfunction (MND) had the most problems in neuropsychological tests, whereas the clinically healthy preterm children and those with cerebral palsy had fewer problems. The problems of MND children emerged in the domain of attention. They also experienced the most problems at school.

CONCLUSIONS

Visuospatial problems were associated with periventricular leukomalacia in MRI, but learning disabilities were most frequent among the preterm children with minor neurologic abnormalities. We recommend closer follow-up of preterm children with MND.

Can cerebral MRI at age 1 year predict motor and intellectual outcomes in very-low-birthweight children?

This follow-up study reports on cerebral MRI findings in 20 very-low-birthweight (VLBW) infants without disabilities at age 1 year in relation to motor, intellectual, and perceptual function at age 6 years. MRI findings, anthropometrics, and Bayley Scales of Infant Development scores at age 1 year as predictors of psychomotor status at age 6 years are also evaluated and compared. Outcome parameters were the Peabody Developmental Motor Scales and the Wechsler Preschool and Primary Scale of Intelligence. The results show that infants with myelin hyperintensities including the centrum semiovale or with occipital hyperintensities with associated ventricular dilatation at age 1 scored lower on the Peabody Gross Motor Locomotion Scale at age 6 than infants with normal myelination or with isolated occipital hyperintensities. This may indicate damage to motor fibers caused by perinatal periventricular leukomalacia. No relation was found between abnormal MRI findings at age 1 and later fine motor, intellectual, and perceptual function. Comparing different age 1-year predictors, an abnormality score defined by MRI was used as an independent predictor of gross motor locomotion function at age 6 years. However, the Bayley Mental Development Index scores and weight at age 1 were more important predictors of later motor and intellectual outcome, respectively, than MRI findings. It is recommended that cerebral MRI should not be used routinely to examine VLBW infants without disabilities at 1 year of age.