Large variability in performance IQ associated with postnatal morbidity, and reduced verbal IQ among school-aged children born preterm

Anemia and Red Blood Cell Transfusions, Cerebral Oxygenation, Brain Injury and Development, and Neurodevelopmental Outcome in Preterm Infants: A Systematic Review

Background: Anemia remains a common comorbidity of preterm infants in the neonatal intensive care unit (NICU). Left untreated, severe anemia may adversely affect organ function due to inadequate oxygen supply to meet oxygen requirements, resulting in hypoxic tissue injury, including cerebral tissue. To prevent hypoxic tissue injury, anemia is generally treated with packed red blood cell (RBC) transfusions. Previously published data raise concerns about the impact of anemia on cerebral oxygen delivery and, therefore, on neurodevelopmental outcome (NDO). Objective: To provide a systematic overview of the impact of anemia and RBC transfusions during NICU admission on cerebral oxygenation, measured using near-infrared spectroscopy (NIRS), brain injury and development, and NDO in preterm infants. Data Sources: PubMed, Embase, reference lists. Study Selection: We conducted 3 different searches for English literature between 2000 and 2020; 1 for anemia, RBC transfusions, and cerebral oxygenation, 1 for anemia, RBC transfusions, and brain injury and development, and 1 for anemia, RBC transfusions, and NDO. Data Extraction: Two authors independently screened sources and extracted data. Quality of case-control studies or cohort studies, and RCTs was assessed using either the Newcastle-Ottawa Quality Assessment Scale or the Van Tulder Scale, respectively. Results: Anemia results in decreased oxygen-carrying capacity, worsening the burden of cerebral hypoxia in preterm infants. RBC transfusions increase cerebral oxygenation. Improved brain development may be supported by avoidance of cerebral hypoxia, although restrictive RBC transfusion strategies were associated with better long-term neurodevelopmental outcomes. Conclusions: This review demonstrated that anemia and RBC transfusions were associated with cerebral oxygenation, brain injury and development and NDO in preterm infants. Individualized care regarding RBC transfusions during NICU admission, with attention to cerebral tissue oxygen saturation, seems reasonable and needs further investigation to improve both short-term effects and long-term neurodevelopment of preterm infants.

Eight-year-old very and extremely preterm children showed more difficulties in performance intelligence than verbal intelligence

Aim

This study determined possible discrepancies between verbal IQ and performance IQ in 8‐year‐old very preterm (VPT) and extremely preterm (EPT) children, and examined associations between verbal IQ and performance IQ, and sociodemographic factors, perinatal factors, early cognitive outcomes and also with school achievement scores.

Methods

This prospective cohort study included 120 eight‐year‐old VPT/EPT children. Cognitive development was assessed at the ages of 2, 5 and 8 years. Eight years’ school achievement results in arithmetic, reading and spelling were collected. Multiple regression analyses were performed to determine predictors of verbal IQ and performance IQ at the age of 8 years and to determine associations with school achievement scores.

Results

Mean performance IQ (89.8) was significantly lower than mean verbal IQ (99.4; Cohen's d = 0.59) at the age of 8 years. Gestational age (GA), small for GA status, and cognitive scores at the ages of 2 and 5 years significantly predicted verbal IQ and performance IQ at the age of 8 years. Performance IQ at age 8 years was an important predictor for arithmetic scores (β = 0.42).

Conclusion

Performance IQ was more strongly affected than verbal IQ in 8‐year‐old VPT/EPT children and was strongly related to mathematical difficulties.

Neurodevelopmental outcomes of infants born prematurely

Long-term follow-up of infants born prematurely is necessary to determine neurodevelopmental outcomes, particularly with the expansion of interest from major disabilities to high prevalence/low severity dysfunctions. Models of pathogenesis include changes due to developmental disruptions and to injury, the magnitude and type of change influenced by the infant's age, and central nervous system recovery and reorganization. Alterations in neurogenesis, migration, myelination, cell death, and synaptogenesis occur even in the absence of insult. Despite increased knowledge regarding these processes, the functional significance of brain abnormalities is unclear. Because of methodologic problems in follow-up studies, it is difficult to characterize outcome definitively. Nonetheless, an acceptable degree of agreement across studies is found with regard to specific neurodevelopmental outcomes: motor/neurologic function, visuomotor integrative skills, IQ, academic achievement, language, executive function, and attention-deficit hyperactivity disorder/behavioral issues. In general, children born prematurely have more problems in these areas than do their normal birth weight counterparts. Suggestions for improved analyses and clarification of outcomes include use of cluster analysis, structural equation modeling, growth curve analysis, developmental epidemiologic approaches, and better control of background variables using risk indexes and factor scores. Better assessment techniques measuring functions documented to be at higher risk of problems are discussed.

Mental health concerns of the premature infant through the lifespan

Because of increased survival rates, neurodevelopmental issues, chronic medical problems, and sometimes complex family issues involved with prematurity, mental health clinicians commonly assess preterm clients and manage their behavioral and mental health problems. Understanding prematurity survival and neurodevelopmental outcomes is important for contextualizing the mental health problems seen in this high-risk population. This article provides a brief overview of prematurity outcomes in the domains of prematurity relevant to practicing child psychiatrists. Prematurity is also examined as it relates to parental mental health challenges, infant mental health outcomes, high frequency attention problems, and psychiatric disorders. The complex interactions between prematurity and family well-being are also highlighted. Finally, evidence-based treatment modalities involved in prevention and management are explored.

Follow-up studies of very low birthweight children in Sweden

Follow-up studies are essential to our knowledge of outcome in very low birthweight (VLBW) or extremely preterm (EPT) infants because those children have a greater risk for developing neurosensory disabilities and behavioural and educational problems and have decreased probability for an optimal transition into adulthood compared to term controls. Outcome data are of interest not only to healthcare professionals but also to parents, schoolteachers and society. The aim of this review is to describe the follow-up studies of seven populations of VLBW or EPT infants performed in Sweden and published between 1995 and 2009.

CONCLUSION

 The time has come to implement evident data from these Swedish follow-up studies into clinical practice and to perform regular and specific follow-up examinations during childhood for all VLBW and EPT children. These assessments, specially designed for high-risk infants, should consider the potential outcomes for neurological, visual, auditory function and cognitive function as well as behaviour and growth, from birth to school-start.

Mental health concerns of the premature infant through the lifespan

Because of increased survival rates, neurodevelopmental issues, chronic medical problems, and sometimes complex family issues involved with prematurity, mental health clinicians commonly assess preterm clients and manage their behavioral and mental health problems. Understanding prematurity survival and neurodevelopmental outcomes is important for contextualizing the mental health problems seen in this high-risk population. This article provides a brief overview of prematurity outcomes in the domains of prematurity relevant to practicing child psychiatrists. Prematurity is also examined as it relates to parental mental health challenges, infant mental health outcomes, high frequency attention problems, and psychiatric disorders. The complex interactions between prematurity and family well-being are also highlighted. Finally, evidence-based treatment modalities involved in prevention and management are explored.

Academic achievement, behavioural outcomes and MRI findings at 15 years of age in very low birthweight children

AIM

To assess cognitive, academic and behavioural functions in 15-year-old very low birthweight (VLBW) children and relate results to gender, neonatal risk factors, growth and magnetic resonance imaging (MRI) findings.

METHODS

Sixty-one out of 86 VLBW children and 57/86 term controls born in the south-east region of Sweden were assessed regarding cognition (WISC III), school outcome, behaviour and growth. VLBW children were examined using cerebral MRI.

RESULTS

VLBW children performed significantly lower than their term controls on WISC III and 49% had IQ lower than 85. Ten VLBW children with IQ < 70 had not been clinically identified earlier and a majority of these children attended mainstream school. VLBW girls had significantly lower total problems scores. Using MRI, white matter damage (WMD) was detected in 16 (27%) children. VLBW boys with WMD had significantly lower IQ than those without. Small occipito-frontal circumference (OFC) correlated with low IQ. Mechanical ventilation and intraventricular haemorrhage (IVH) showed significant correlations with lower IQ and reading skills.

CONCLUSION

VLBW children achieved poorer results compared with their controls in cognitive tests. Mechanical ventilation and IVH were related to poorer academic outcome. Many of the children with low IQ had not been identified earlier. Therefore, we recommend that VLBW children undergo an IQ test before beginning school in order to receive adequate support.

Health-related quality of life for extremely low birth weight adolescents in Canada, Germany, and the Netherlands

OBJECTIVE

The goal was to compare health-related quality of life of 12- to 16-year-old adolescents born at an extremely low birth weight in regional cohorts from Ontario (Canada), Bavaria (Germany), and the Netherlands.

METHODS

Patients were extremely low birth weight survivors from Canada, Germany, and the Netherlands. Health-related quality of life was assessed with Health Utilities Index 3. Missing data were substituted by proxy reports. Differences in mean Health Utilities Index 3 scores were tested by using analysis of variance. Differences in the numbers of children with affected attributes were tested by using logistic regression analyses.

RESULTS

Survival rates were similar; response rates varied between 71% and 90%. Significant differences in health-related quality of life were found between the cohorts, with Dutch children scoring highest on Health Utilities Index 3 and German children scoring lowest, independent of birth weight, gestational age, and cerebral palsy. Differences in mean utility scores were mainly attributable to differences in the cognition health attribute. Most of the results were corroborated by logistic regression analyses.

CONCLUSIONS

There were significant differences between the 3 cohorts in health-related quality of life, not related to differences in birth weight, gestational age, or cerebral palsy. Survival and response rates alone cannot explain these differences.

Impaired executive functioning in young adults born very preterm

Individuals born very preterm (VPT) are at increased risk of perinatal brain injury and long-term cognitive and behavioral problems. Executive functioning, in particular, has been shown to be impaired in VPT children and adolescents. This study prospectively assessed executive function in young adults who were born VPT (<33 weeks of gestation) [n = 61; mean age, 22.25 (+/-1.07) years; range, 20.62-24.78 years] and controls [n = 64; mean age, 23.20 (+/-1.48) years; range, 19.97-25.46 years]. Tests used comprised the Wechsler Abbreviated Scale of Intelligence (WASI), the Hayling Sentence Completion Test (HSCT), the Controlled Oral Word Association Test (COWAT), the Animal and Object test, the Trail-Making Test (TMT), and the Test of Attentional Performance (TAP). VPT participants showed specific executive function impairments in tasks involving response inhibition and mental flexibility, even when adjusting for IQ, gender, and age. No significant associations were observed between executive function test scores and perinatal variables or neonatal ultrasound classification. The results suggest that, although free from major physical disability, VPT young adults perform worse than controls on tasks involving selective aspects of executive processing, such as mental flexibility and response inhibition.

Long-term neurodevelopmental outcome of preterm children with unilateral cerebral lesions diagnosed by neonatal ultrasound

OBJECTIVE

Little information is available on long-term neurodevelopmental outcome of preterm infants with unilateral cerebral lesions detected by neonatal cranial ultrasound. This study aims to investigate the long-term outcome in a cohort of very preterm infants with unilateral cerebral lesions acquired in the perinatal period.

METHODS

A prospective cohort study of 668 preterm infants (<33 weeks gestation; birth years 1985-1991) at a single tertiary perinatal centre in the UK. All infants had serial cranial ultrasound examination in the neonatal period. Outcome was assessed at age 8 years with the Wechsler Intelligence Scales for Children (WISC-R), Test of Visuo-motor Integration (VMI) and the Test of Motor Impairment (TOMI).

RESULTS

Of the 668 infants, 369 infants had normal ultrasound scans. Two hundred and ninety nine children had bilateral parenchymal or non-parenchymal lesions (57 left-sided, 41 right-sided, 201 bilateral). Five hundred and thirty four (79%) children attended follow-up at age 8 years. Mean Full Scale IQ (FSIQ) was 101 (SD+/-16), 93 (SD+/-17), 102 (SD+/-17) and 91 (SD+/-21) for normal, left-sided, right-sided and bilateral lesion groups respectively. In all groups verbal IQ (VIQ) was higher than performance IQ (PIQ). Scores of FSIQ, VIQ and PIQ, VMI and TOMI were significantly different between the groups. After exclusion of children with parenchymal lesions, however, the difference was only significant for the TOMI scores. In all tests, children with left-sided lesions performed poorer than children with right-sided lesions.

CONCLUSIONS

In this cohort of preterm infants with unilateral cerebral lesions, verbal function was preserved over non-verbal function independently of the side of lesion. Furthermore, the results suggest that the neurodevelopmental outcome of children with left-sided lesions is less favourable than that of children with right-sided lesions.

Neurodevelopmental outcomes of infants born prematurely

Long-term follow-up of infants born prematurely is necessary to determine neurodevelopmental outcomes, particularly with the expansion of interest from major disabilities to high prevalence/low severity dysfunctions. Models of pathogenesis include changes due to developmental disruptions and to injury, the magnitude and type of change influenced by the infant's age, and central nervous system recovery and reorganization. Alterations in neurogenesis, migration, myelination, cell death, and synaptogenesis occur even in the absence of insult. Despite increased knowledge regarding these processes, the functional significance of brain abnormalities is unclear. Because of methodologic problems in follow-up studies, it is difficult to characterize outcome definitively. Nonetheless, an acceptable degree of agreement across studies is found with regard to specific neurodevelopmental outcomes: motor/neurologic function, visuomotor integrative skills, IQ, academic achievement, language, executive function, and attention-deficit hyperactivity disorder/behavioral issues. In general, children born prematurely have more problems in these areas than do their normal birth weight counterparts. Suggestions for improved analyses and clarification of outcomes include use of cluster analysis, structural equation modeling, growth curve analysis, developmental epidemiologic approaches, and better control of background variables using risk indexes and factor scores. Better assessment techniques measuring functions documented to be at higher risk of problems are discussed.

Les troubles du développement des enfants grands prématurés mesurés à l’âge scolaire

Advances in perinatal care have lead to the survival of an increasing number of children born very premature. The purpose of this review is to discuss findings in the literature regarding long term developmental outcome of infants born prematurely especially for studies with children at least 5 years old, born in the 80's or after, in a context of care with increased use of antenatal corticoids, in utero transfer, and surfactant therapy. Developmental sequelae, which are seen in children older than those presenting severe deficiencies, concerns a greater number of very premature children. They have poorer outcomes than term children or normal birth weight controls for cognitive-neuropsychological skills, school performances and behavior. Long term follow up of these children shows that consequences are still present for adolescents or young adults. There is a gradient of developmental sequelae in children that is inversely related to decreasing gestational age or birth weight. Developmental sequelae are related to neonatal medical complications and social risks factors. Research should be conducted in order to better understand etiology and neuropathological basis of sequelae, and the long term developmental implication of being born very premature and the type of care or intervention which could improve their development. An early and regular follow up by a team specialized in child development should be proposed in order to detect developmental sequelae and propose early intervention.

Follow up of children after antenatal treatment for alloimmune thrombocytopenia

OBJECTIVE

To evaluate the long-term follow-up of surviving offspring after antenatal treatment for fetal or neonatal alloimmune thrombocytopenia (FNAIT).

PATIENTS

Fifty children at risk of FNAIT were antenatally treated with maternal intravenous immunoglobulins (IVIG) (n=11), IVIG with intrauterine platelet transfusions (IUPT) (n=26) or IUPT alone (n=9). In four cases (n=4), only fetal blood sampling (FBS) was performed. One child died in the neonatal period and one was lost to follow up.

METHODS

The remaining 48 children, aged 1.3-11.6 years (median 5.1 years), were given both general and neurological examinations and assessed on their development and susceptibility for infections or atopic constitution. In addition, immunoglobulin levels were measured in 17 infants, aged 5 years and older.

RESULTS

Intracranial hemorrhage (ICH) was not observed. The general health and neurodevelopmental outcome in the children was comparable to a normal Dutch population. Children not exposed to maternal IVIG treatment had significantly more infections and hearing problems than children exposed to IVIG treatment or the normal population. Immunoglobulin G, A and M levels were within the normal range, independent of treatment and severity of FNAIT. A high IgE level was more frequently seen in children exposed to IVIG, but did not result in clinical consequences such as allergy or atopy.

CONCLUSIONS

Antenatal treatment of children for FNAIT did not affect general health or neurodevelopmental outcome. In particular, exposure to IVIG in utero showed no adverse effect on the clinical outcome of these children.

Physical growth and neurodevelopmental outcome of nonhandicapped low-risk children born preterm

BACKGROUND

Outcome studies on the effects of prematurity are increasingly restricted to extremely immature infants with birth weight below 1000 g or gestational age below 26 weeks. In contrast, studies comprising low-risk preterm infants are rare.

AIM

To examine growth and neurodevelopmental outcome, 70 low-risk low birth weight (LBW) children without neurological impairment were followed from birth to 7 years of age. At 7 years of age, LBW children were compared to a matched control group born at term.

METHODS

Postnatal growth was measured at 20 months in the LBW group and at 7 years in LBW and control children. At 20 months, the LBW group was assessed with the Griffiths Scales. At 7 years, LBW and control children were assessed with a neuropsychological test battery comprising tests for language, visual-perceptual, visual-motor, fine and gross motor abilities.

RESULTS

At 7 years of age, the frequency of children with low (3rd-9th percentile) or subnormal (<3rd percentile) growth parameters was increased in the LBW group. The Mean Griffiths Developmental Quotient (DQ) of the preterm group was normal (102.3+/-8.4), and there were only two results below DQ 85. There was no difference between 49 children appropriate for gestational age and 21 small for gestational age (SGA) children. At 7 years of age, reduced mean test results in the range of -0.5 SDS were observed for language and visual-motor abilities in the preterm group. This was due to an increased frequency of LBW children with moderately (SDS -1.0 to -2.0 SDS) subnormal test results. Even for the slightly LBW group (2000 to 2499 g), poorer language abilities were confirmed.

CONCLUSION

All LBW infants, including low-risk populations, should be included in a follow-up program in order to detect deficits early in life and begin treatment before school entry.