Developmental coordination disorder at 8 years of age in a regional cohort of extremely-low-birthweight or very preterm infants

Prevalence of motor-skill impairment in preterm children who do not develop cerebral palsy: a systematic review

AIM

Motor skill impairment is a common negative outcome in children born preterm who do not develop cerebral palsy (CP). This study aimed to conduct a systematic review of current data to provide an accurate estimate of the prevalence of non-CP motor impairment in preterm children at school age.

METHOD

We searched the Medline, PubMed, and PsycInfo databases and relevant journals to identify all studies published post-1990 that reported the prevalence of motor impairment in school-aged children born preterm (<37 wks' gestation) using standardised motor assessment batteries. We applied a range of exclusionary criteria, with 11 studies included in the final analyses. We identified two levels of motor impairment commonly reported - mild-moderate and moderate - and conducted a random effects meta-analysis to produce a prevalence estimate for each.

RESULTS

The pooled estimate for mild-moderate impairment in preterm children was 40.5/100. and for moderate motor impairment the estimate was 19.0/100. There was also a trend for lower motor impairment levels in samples born before 1990 compared with those born after 1990.

INTERPRETATION

Children born preterm are at increased risk of motor impairment, with prevalence three to four times greater than in the general population. This highlights the need for improved surveillance and intervention strategies in this group of children.

Behavioural and emotional outcome of very low birth weight infants--literature review

OBJECTIVE

To examine whether low birth weight (LBW) children are at greater risk for behavioural and emotional problems than normal birth weight children.

METHODS

Electronic databases (PubMed, Google) were searched. Key search terms (LBW, emotional behavioural outcome) were used to identify possible studies. Selection of studies was limited to those including detailed assessment of behavioural and/or emotional outcome of very low birth weight or very preterm infants with normal term infants as controls, published from the year 2000 to date. A total of 20 studies were identified for inclusion in our review.

RESULTS

Overall studies showed a significant increase in behavioural problems in particular poor attention span, withdrawn behaviour and poorer adaptive functioning. Rates of a clinically significant neurobehavioural impairment in cases ranged from 25% to 55% with controls displaying a relatively constant rate of around 7%. Attention problems without hyperactivity (ADD) were more common than 'classical attention deficit/hyperactivity disorder' in LBW children. Only 4% of the LBW children had previously been referred to a consultant psychiatric suggesting that at present these problems are being under-recognised.

CONCLUSION

VLBW or very preterm infants are at significant risk of behavioural and emotional problems. The risk is further increased when cognitive or motor difficulties are present or when social circumstances are poor.

Fetal programming of infant neuromotor development: the generation R study

The objective of the study was to examine whether infant neuromotor development is determined by fetal size and body symmetry in the general population. This study was embedded within the Generation R Study, a population-based cohort in Rotterdam. In 2965 fetuses, growth parameters were measured in mid-pregnancy and late pregnancy. After birth, at age 9 to 15 wks, neuromotor development was assessed with an adapted version of Touwen's Neurodevelopmental Examination. Less optimal neuromotor development was defined as a score in the highest tertile. We found that higher fetal weight was beneficial to infant neurodevelopment. A fetus with a 1-SD score higher weight in mid-pregnancy had an 11% lower risk of less optimal neuromotor development (OR: 0.89; 95% CI: 0.82-0.97). Similarly, a fetus with a 1-SD score larger abdominal-to-head circumference (AC/HC) ratio had a 13% lower risk of less optimal neuromotor development (OR: 0.87; 95% CI: 0.79-0.96). These associations were also present in late pregnancy. Our findings show that fetal size and body symmetry in pregnancy are associated with infant neuromotor development. These results suggest that differences in infant neuromotor development, a marker of behavioral and cognitive problems, are at least partly caused by processes occurring early in fetal life.

Academic, social, and behavioral outcomes at age 12 of infants born preterm

The effects of gradient levels of perinatal morbidity on school outcomes have been investigated at age 12 in four preterm groups, classified as healthy (no medical or neurological illness), medical morbidity, neurological morbidity, and small-for-gestational-age (SGA), and a full-term comparison group. Teachers report on academic competence, social skills, and problem behaviors. Data on school type, classroom setting, and school service use are gathered from school records. Preterm groups are found to be equivalent to full-term peers in social skills and problem behavior. Preterm groups with neurological and SGA morbidity have the lowest academic competence scores. Unexpectedly, preterm infants with medical morbidity have higher academic competence scores compared with the other preterm groups. School service use increases with greater perinatal morbidity and is contingent on multiple rather than single indicators of perinatal morbidity. Continued monitoring of preterm infants through early adolescence will ensure that appropriate school services and resources are available to maximize their school success.

Motor ability in children treated for idiopathic clubfoot. A controlled pilot study

Background

To study motor ability at seven years of age in children treated for idiopathic clubfoot and its relation to clubfoot laterality, foot status and the amount of surgery performed.

Methods

Twenty children (mean age 7.5 years, SD 3.2 months) from a consecutive birth cohort from our hospital catchments area (300.000 inhabitants from southern Sweden) were assessed with the Movement Assessment Battery for Children (MABC) and the Clubfoot Assessment Protocol (CAP).

Results

Compared to typically developing children an increased prevalence of motor impairment was found regarding both the total score for MABC (p < 0.05) and the subtest ABC-Ball skills (p < 0.05). No relationship was found between the child's actual foot status, laterality or the extent of foot surgery with the motor ability as measured with MABC. Only the CAP item "one-leg stand" correlated significantly with the MABC (rs = -0.53, p = 0.02).

Conclusions

Children with idiopathic clubfoot appear to have an increased risk of motor activity limitations and it is possible that other factors, independent of the clinical status, might be involved. The ability to keep balance on one leg may be a sufficient tool for determining which children in the orthopedic setting should be more thoroughly evaluated regarding their neuromotor functioning.

Neural correlates of developmental coordination disorder: a review of hypotheses

Affecting 5% to 6% of school-age children, developmental coordination disorder is characterized by a marked impairment of motor coordination that significantly interferes with activities of daily living and academic achievement. Little is known about the etiology of developmental coordination disorder, but the disorder often coexists with attention-deficit hyperactivity disorder (ADHD), speech/language impairment, and/or reading disability. This comprehensive review examines the literature supporting or refuting hypothesized neural correlates of developmental coordination disorder and suggests directions for future research. Potential sources of neuropathology include the cerebellum, parietal lobe, corpus callosum, and basal ganglia. Comorbidities and deficits associated with developmental coordination disorder are highly suggestive of cerebellar dysfunction; yet, given the heterogeneity of this disorder, it is likely that the cerebellum is not the only neural correlate. Neuroimaging studies and behavioral investigations of learning-related change in motor behavior are the next critical step in enhancing our understanding of developmental coordination disorder.

Early emergence of behavior and social-emotional problems in very preterm infants

OBJECTIVE

Children born very preterm are reported to have an increased frequency of social, emotional, and behavioral problems at school age compared with their peers born at term. The primary aim of this study was to compare social-emotional difficulties and competencies of very preterm and full-term children at 2 years' corrected age. In addition, the relation between perinatal variables and early behavior problems was also examined to help identify those very preterm children most at risk.

METHOD

At 2 years' corrected age, the parents of 188 very preterm (gestational age <30 weeks or birth weight <1,250 g) and 70 full-term (gestational age >or=37 weeks) children completed the Infant Toddler Social and Emotional Assessment to determine externalizing, internalizing, and dysregulation problems and social-emotional competencies. For the very preterm sample, extensive perinatal data were collected including sex, birth weight, gestational age, chronic lung disease, and postnatal steroids, as well as neonatal cerebral white matter abnormalities detected by magnetic resonance imaging.

RESULTS

The very preterm children at 2 years demonstrated significantly higher internalizing and dysregulation scores and lower competence scores than peers born at term. There was no significant difference in externalizing scores between groups. Female sex, lower birth weight z score, white matter abnormalities, and postnatal corticosteroids were significantly associated with lower competence scores in the very preterm group.

CONCLUSIONS

Very preterm children exhibit higher rates of behavior problems early in development, in particular internalizing and dysregulation problems and poorer competence.

Análise comparativa da coordenação motora de crianças nascidas a termo e pré-termo, aos 7 anos de idade

OBJETIVO: comparar o desenvolvimento motor, na idade escolar, de crianças nascidas a termo e pré-termo. MÉTODOS: participaram do estudo dois grupos de crianças, com sete anos de idade: a) grupo pré-termo com 35 crianças, de famílias de baixa renda, nascidas com idade gestacional <34 semanas e/ou peso ao nascimento <1500 g, e b) grupo controle com 35 crianças nascidas a termo, com idade, sexo e nível socioeconômico equivalente ao grupo pré-termo. Todas as crianças foram avaliadas com o teste Movement Assessment Battery for Children (M-ABC). RESULTADOS: o teste de Wilcoxon indicou diferença significativa entre os grupos no escore total (Z=-4,866, p<0,001) e nas subáreas do M-ABC, com pior desempenho no grupo pré-termo. CONCLUSÃO: 57% das crianças do grupo pré-termo apresentaram sinais de transtorno da coordenação, o que ressalta a importância do acompanhamento do desenvolvimento até a idade escolar.

Nutritional support of very low birth weight newborns

Nutritional support to promote optimal postnatal growth for very low birth weight (VLBW) newborns less than 1500 g at birth during the initial prolonged hospitalization is a significant issue. This article reviews the concepts involved in the nutritional support of VLBW newborns, including definitions and discussions of growth, optimal postnatal growth, body composition, initial weight loss, growth expectations, growth assessment tools used during the postnatal period, the relation between inadequate nutrition and neurodevelopment, the relation between protein intake and cognitive outcome, postnatal nutrition balance, the potential for programming of future adult-onset chronic conditions, a review of fetal nutritional intake, and current recommendations for nutritional support of VLBW newborns.

The association of lung disease with cerebral white matter abnormalities in preterm infants

OBJECTIVE

Preterm infants have a high incidence of neurodevelopmental impairment associated with diffuse cerebral white matter abnormalities and also a high incidence of serious respiratory disease. However, it is unclear if lung disease and brain injury are related, and previous research has been impeded by confounding effects, including prematurity and infection. Using a new approach that permits multivariate statistical analysis, we tested the hypothesis that lung disease is associated with specific white matter abnormalities, detected as reduced fractional anisotropy (FA) in diffusion tensor imaging data.

METHODS

Fifty-three preterm infants with no evidence of focal abnormality on conventional MRI were studied at term-equivalent age by using tract-based spatial statistics, an automated observer-independent method for voxelwise analysis of major white matter pathways.

RESULTS

In several white matter tracts, FA decreased with a linear relation to the gestational age at birth. Independent of the confounding effects of prematurity and age at scan, respiratory disease was associated with specific white matter abnormalities in preterm infants; those infants receiving mechanical ventilation for >2 days in the perinatal period (n = 10) showed reduced FA in the genu of the corpus callosum, whereas subjects with chronic lung disease (n = 15) displayed a reduction in FA in the left inferior longitudinal fasciculus.

CONCLUSION

Independent of the degree of prematurity, respiratory disease is associated with cerebral white matter abnormalities.

Motor coordination difficulties and physical fitness of extremely-low-birthweight children

Motor coordination difficulties and poor fitness exist in the extremely low birthweight (ELBW) population. This study investigated the relative impact of motor coordination on the fitness of ELBW children aged 11 to 13 years. One hundred and nine children were recruited to the study: 54 ELBW participants (mean age at assessment 12y 6mo; 31 male, 23 female; mean birthweight 769g, SD 148g; mean gestational age 26.6 weeks, SD 2.1 weeks) and 55 comparison children (mean age at assessment 12y 5mo; 28 males, 27 females; at least 37 weeks' gestation). All children completed the Movement Assessment Battery for Children (MABC), functional tests of postural stability and strength, growth measures, and tests of respiratory function. Maximal oxygen uptake (VO(2)max) was calculated from a 20m shuttle run test as a measure of fitness. The ELBW group had greater problems with postural stability (p=0.001) and motor coordination (p=0.001), with 70% rated as having a definite motor problem on the MABC brackets (those who scored less than the 5(th) centile on the MABC). The ELBW was also less fit than the comparison group (p=0.001), with 45% below the 10th centile for VO(2)max. There were differences between the groups for growth, strength, and particularly respiratory function. However, respiratory function did not significantly correlate with VO(2)max in the ELBW group. Motor coordination was the most powerful predictor of VO(2)max in both the ELBW (p=0.001) and the comparison groups (p=0.001).

Incidence of epilepsy in extremely low-birthweight infants (<1,000 g): a population study of central and southern Sardinia

PURPOSE

With the development of intensive care, the survival of extremely low-birthweight (ELBW) infants (<1,000 g) has greatly improved. The aim of our study was to report the incidence of epilepsy after a follow-up of >7 years in a population of ELBW children, born in central and southern Sardinia between 1991 and 2000.

METHODS

We analyzed data of 104 children. All infants had had serial cranial ultrasound echography (CUE) in the neonatal period and some also had magnetic resonance imaging (MRI). At last follow-up we evaluated the occurrence of epilepsy through a review of clinical charts and a structured telephone interview.

RESULTS

In 11 (10.6%) of 104 of children we observed febrile seizures (FS). Epilepsy occurred in 9 (8.6%) of 104 ELBW children, and in these patients a frequent positive family history for epilepsy and/or FS was present. In four epilepsy patients CUE was highly pathologic, showing intraventricular hemorrhage (IVH) of grade IV and in two mildly abnormal (IVH of grade I-II). In three additional children with normal neonatal ultrasound scan, a later magnetic resonance imaging (MRI) study revealed lesions related to neonatal insult.

DISCUSSION

In our ELBW population, epilepsy had an incidence clearly superior to that expected in infancy (8.6% vs. 0.6-0.8%). A frequent positive familiar history for epilepsy and/or FS suggests that a genetic predisposition may also play a role. Subjects with highly abnormal CUE are a subgroup with high risk for seizures; however, epilepsy can occur even with normal CUE.

Motor impairment and low achievement in very preterm children at eight years of age

AIM

To examine the concurrence of motor impairment and academic underachievement in a group of very preterm children at 8 years of age.

METHODS

All surviving children with a gestational age less than 30 weeks, admitted to the neonatal intensive care unit between 1987 and 1997, were prospectively enrolled in developmental follow-up. Children with a neurosensory disability or a low intelligence score (FSIQ < or = 75 points) were excluded. At 8 years of age the Bruininks Oseretsky Test of Motor Proficiency and standardised tests of academic achievement were administered to a sample of 323 very preterm children.

RESULTS

One hundred and one (31.3%) of these very preterm children were identified as having Developmental Coordination Disorder (DCD). Of the children with DCD, 54.4% also had underachievement in literacy and/or numeracy. As the severity of motor impairment increased so too did the severity and complexity of underachievement. Significantly fewer children with motor impairments participated in after-school sporting activities. Children with DCD required more mechanical ventilation support during their hospital admission.

CONCLUSIONS

This study demonstrated that a significant proportion of children born very preterm find both motor and academic skills difficult in early school years.

Does gestational duration within the normal range predict infant neuromotor development?

AIM

To examine the extent to which infant neuromotor development is determined by gestational duration and birth weight within the normal range.

METHODS

The study was embedded within the Generation R Study, a population-based cohort in Rotterdam, the Netherlands. An adapted version of Touwen's Neurodevelopmental Examination was used to assess 3224 infants (1576 males and 1648 females) at corrected ages between 9 and 15 weeks. Non-optimal neuromotor development was defined as a score in the highest tertile.

RESULTS

Infant neuromotor development was significantly affected by gestational duration (odds ratio 0.8, 95% confidence interval 0.7;0.8). Adding a quadratic term of gestational duration to the model revealed a highly significant curvilinear association between gestational duration and neuromotor development; after adjusting for post-conceptional age this was still significant. Although babies with a 1 kg lower birth weight had a 30% higher risk of non-optimal neuromotor development, this association disappeared after adjustment for post-conceptional age.

CONCLUSIONS

Our findings indicate that differences in infant neuromotor development can be explained even by variations in gestational duration within the normal range. If an infant is found to have minor neuromotor delays, account should be taken of this.

Neurodevelopmental outcomes of preterm infants

PURPOSE OF REVIEW

Preterm birth is emerging as a major public health problem in the USA. Improvements in preterm birth and survival rates translate to increasing numbers of preterm survivors, and many develop motor, cognitive and sensory impairments.

RECENT FINDINGS

The review discusses the recently reported prevalence of neurodevelopmental disabilities in preterm survivors, in addition to studies of factors associated with neurodevelopmental outcome.

SUMMARY

A 2007 report from the Institute of Medicine emphasizes preterm birth as an increasingly common complex condition with multiple risk factors resulting from multiple gene-environmental interactions, leading to birth before 37 weeks gestation, neonatal complications and a disproportionately high contribution to neurodevelopmental disability rates. The increased risk of cerebral palsy with decreasing gestational age categories is well documented, but recent studies highlight the range and severity of cognitive, sensory, language, visual-perceptual, attention and learning deficits in very preterm children. Combined with increasingly sophisticated neuroimaging studies to identify perinatal risk factors, neurodevelopmental follow-up of neonatal intensive care unit trials offers the potential to really improve our understanding of how the preterm brain develops, is injured and recovers from injuries. Knowledge of what influences neurodevelopmental outcomes is key to developing better treatment strategies.

Using proteomic analysis of the human amniotic fluid to identify histologic chorioamnionitis

OBJECTIVE

To estimate the relationship between histologic chorioamnionitis and four amniotic fluid proteomic biomarkers characteristic of inflammation (defensins 2 and 1, calgranulins C and A).

METHODS

One hundred fifty-eight women with singleton pregnancies had a clinically indicated amniocentesis to rule out inflammation and infection in the context of preterm labor or preterm premature rupture of membranes. A proteomic fingerprint (Mass Restricted score) was generated from amniotic fluid using surface-enhanced laser desorption ionization time-of-flight mass spectrometry. The Mass Restricted score ranges from 0 to 4 (none to all four biomarkers present) in direct relationship with severity of intra-amniotic inflammation. Presence or absence of biomarkers was analyzed in relationship to placental pathology. Criteria for severity of histologic chorioamnionitis were 3 stages and 4 grades of inflammation of the amnion, choriodecidua and chorionic plate.

RESULTS

The prevalence of histologic chorioamnionitis was 64% (stage I 12%, stage II 16%, and stage III 37%). The Mass Restricted score significantly correlated with stages of histologic chorioamnionitis (r=0.539, P<.001), grades of choriodeciduitis (r=0.465, P<.001), and amnionitis (r=0.536, P<.001). African-American women were overrepresented in the group with severe inflammation (Mass Restricted score 3-4, P=.022). Of the four biomarkers of the Mass Restricted score, calgranulin C had the strongest relationship with presence of stage III chorioamnionitis, independent of race, amniocentesis-to-delivery interval, and gestational age.

CONCLUSION

Proteomic analysis of amniotic fluid provides an opportunity for early recognition of histologic chorioamnionitis. This methodology may in the future identify candidates for antenatal therapeutic interventions.

LEVEL OF EVIDENCE

II.

Low birthweight and preterm birth in young people with special educational needs: a magnetic resonance imaging analysis

BACKGROUND

Although neuroanatomical and cognitive sequelae of low birthweight and preterm birth have been investigated, little is understood as to the likely prevalence of a history of low birthweight or preterm birth, or neuroanatomical correlates of such a history, within the special educational needs population. Our aim was to address these issues in a sample of young people receiving additional learning support.

METHODS

One hundred and thirty-seven participants aged 13-22 years, receiving additional learning support, were recruited via their schools or colleges and underwent structural magnetic resonance imaging (MRI). Obstetric records, available in 98 cases, included birthweight and gestational data in 90 and 95 cases, respectively. Both qualitative and quantitative voxel-based analyses of MRI data were conducted.

RESULTS

A history of low birthweight and preterm birth was present in 13.3% and 13.7% of cases, respectively. Low birthweight and preterm birth were associated with specific qualitative anomalies, including enlargement of subarachnoid cisterns and thinning of the corpus callosum. Low birthweight was associated with reduced grey matter density (GMD) in the superior temporal gyrus (STG) bilaterally, left inferior temporal gyrus and left insula. Prematurity of birth was associated with reduced GMD in the STG bilaterally, right inferior frontal gyrus and left cerebellar hemisphere. Comparison of subjects with no history of low birthweight or preterm birth with a previously defined control sample of cognitively unimpaired adolescents (n = 72) demonstrated significantly greater scores for several anomalies, including thinning of the corpus callosum, loss of white matter and abnormalities of shape of the lateral ventricles.

CONCLUSION

Although a two-fold increased prevalence of a history of low birthweight and preterm birth exists within the special educational needs population, other aetiological factors must be considered for the overwhelming majority of cases. Neuroanatomical findings within this sample include qualitative anomalies of brain structure and grey matter deficits within temporal lobe structures and the cerebellum that persist into adolescence. These findings suggest a neurodevelopmental mechanism for the cognitive difficulties associated with these obstetric risk factors.

An overview of mortality and sequelae of preterm birth from infancy to adulthood

Survival rates have greatly improved in recent years for infants of borderline viability; however, these infants remain at risk of developing a wide array of complications, not only in the neonatal unit, but also in the long term. Morbidity is inversely related to gestational age; however, there is no gestational age, including term, that is wholly exempt. Neurodevelopmental disabilities and recurrent health problems take a toll in early childhood. Subsequently hidden disabilities such as school difficulties and behavioural problems become apparent and persist into adolescence. Reassuringly, however, most children born very preterm adjust remarkably well during their transition into adulthood. Because mortality rates have fallen, the focus for perinatal interventions is to develop strategies to reduce long-term morbidity, especially the prevention of brain injury and abnormal brain development. In addition, follow-up to middle age and beyond is warranted to identify the risks, especially for cardiovascular and metabolic disorders that are likely to be experienced by preterm survivors.