Congenital anomalies in children with cerebral palsy: a population-based record linkage study

Severe Congenital Heart Defects and Cerebral Palsy

OBJECTIVE

To report the prevalence of cerebral palsy (CP) in children with severe congenital heart defects (sCHD) and the outcome/severity of the CP.

METHODS

Population-based, data linkage study between CP and congenital anomaly registers in Europe and Australia. The EUROCAT definition of severe CHD (sCHD) was used. Linked data from 4 regions in Europe and 2 in Australia were included. All children born in the regions from 1991 through 2009 diagnosed with CP and/or sCHD were included. Linkage was completed locally. Deidentified linked data were pooled for analyses.

RESULTS

The study sample included 4989 children with CP and 3684 children with sCHD. The total number of livebirths in the population was 1 734 612. The prevalence of CP was 2.9 per 1000 births (95% CI, 2.8-3.0) and the prevalence of sCHD was 2.1 per 1000 births (95% CI, 2.1-2.2). Of children with sCHD, 1.5% (n = 57) had a diagnosis of CP, of which 35 (61%) children had prenatally or perinatally acquired CP (resulting from a brain injury at ≤28 days of life) and 22 (39%) children had a postneonatal cause (a brain injury between 28 days and 2 years). Children with CP and sCHD more often had unilateral spastic CP and more intellectual impairments than children with CP without congenital anomalies.

CONCLUSIONS

In high-income countries, the proportion of children with CP is much higher in children with sCHD than in the background population. The severity of disease in children with CP and sCHD is milder compared with children with CP without congenital anomalies.

Making waves: The changing tide of cerebral palsy

Cerebral palsy (CP) is a broad diagnosis unbound by aetiology and is based on a clinical examination demonstrating abnormalities of movement or posture. CP represents a static neurological condition, provided that neurodegenerative conditions, leukoencephalopathies and neuromuscular disorders are excluded. In paediatrics, the genetic conditions associated with CP are rapidly increasing, with primary and overlapping neurodevelopmental conditions perhaps better categorised by the predominant clinical feature such as CP, intellectual disability, autism spectrum disorder or epilepsy. Progress in molecular genetics may challenge what constitutes CP, but a genetic diagnosis does not negate the CP diagnosis. As clinicians working in the field, we discuss the changing tide of CP. Neuroimaging provides essential information through pattern recognition and demonstration of static brain changes. We present examples of children where a layered clinical diagnosis or dual aetiologies are appropriate. We also present examples of children with genetic causes of CP to highlight the challenges and limitations of neuroimaging to provide an aetiological diagnosis. In consultation with a geneticist, access to genomic testing (exome or genome sequencing) is now available in Australia under Medicare billing for children under the age of 10 with dysmorphic features, one or more major structural organ anomalies, (an evolving) intellectual disability or global developmental delay. We encourage the uptake of genomic testing in CP, because it can be difficult to tell whether a child has an environmental or genetic cause for CP. A specific genetic diagnosis may change patient management, reduce guilt and enable more distinctive research in the future to assist with understanding disease mechanisms.

Neuromuscular electrical stimulation to augment lower limb exercise and mobility in individuals with spastic cerebral palsy: A scoping review

Background: Neuromuscular Electrical Stimulation (NMES) is an emerging assistive technology applied through surface or implanted electrodes to augment skeletal muscle contraction. NMES has the potential to improve function while reducing the neuromuscular impairments of spastic cerebral palsy (CP). This scoping review examines the application of NMES to augment lower extremity exercises for individuals with spastic CP and reports the effects of NMES on neuromuscular impairments and function in spastic CP, to provide a foundation of knowledge to guide research and development of more effective treatment.

Methods: A literature review of Scopus, Medline, Embase, and CINAHL databases were searched from 2001 to 2 November 2021 with identified inclusion and exclusion criteria.

Results: Out of 168 publications identified, 33 articles were included. Articles on three NMES applications were identified, including NMES-assisted strengthening, NMES-assisted gait, and NMES for spasticity reduction. NMES-assisted strengthening included the use of therapeutic exercises and cycling. NMES-assisted gait included the use of NMES to improve gait patterns. NMES-spasticity reduction included the use of transcutaneous electrical stimulation or NMES to decrease tone. Thirteen studies investigated NMES-assisted strengthening, eleven investigated therapeutic exercise and demonstrated significant improvements in muscle structure, strength, gross motor skills, walking speed, and functional mobility; three studies investigated NMES-assisted cycling and demonstrated improved gross motor skills and walking distance or speed. Eleven studies investigated NMES-assisted gait and demonstrated improved muscle structure, strength, selective motor control, gross motor skills, and gait mechanics. Seven studies investigated NMES for spasticity reduction, and five of the seven studies demonstrated reduced spasticity.

Conclusion: A growing body of evidence supports the use of NMES-assisted strengthening, NMES-assisted gait, and NMES for spasticity reduction to improve functional mobility for individuals with spastic CP. Evidence for NMES to augment exercise in individuals with spastic CP remains limited. NMES protocols and parameters require further clarity to translate knowledge to clinicians. Future research should be completed to provide richer evidence to transition to more robust clinical practice.

Survey on children with cerebral palsy in Tochigi Prefecture, Japan

BACKGROUND

The incidence of cerebral palsy (CP) is influenced by perinatal medicine and regional medical systems. We investigated the recent incidence of CP and the current problems of children with CP in living at home under an advanced perinatal medical system in Tochigi Prefecture, Japan.

METHODS

A clinical datasheet survey was performed among 13 hospitals and six rehabilitation facilities treating children with CP born in Tochigi Prefecture to estimate the incidence of CP among children born between 2009 and 2013. The severity of motor and intellectual impairment, presumed causal factors, complications, and provided medical interventions were investigated and compared between preterm and term-born children with CP.

RESULTS

The incidence of CP was 1.6 per 1000 live births. Shorter gestation period and lower birthweight were associated with a higher incidence of CP. Fifty-one percent of children with CP were non-ambulatory and 55% had severe to profound intellectual impairment. Episodes of neonatal asphyxia and periventricular leukomalacia were the most frequent causal factors; both were significantly more frequent in preterm than in term-born children. Approximately 30% of children with CP had respiratory disorders, dysphagia, or epilepsy; 62% received medical interventions, including medication, mechanical ventilation, oxygen therapy, tube feeding, and intraoral/intranasal suction.

CONCLUSION

We found the incidence of CP to be lower in comparison to previous Japanese studies. However, the motor and intellectual impairments were severe, and many children with CP and their families were burdened by daily medical care. Public support systems should be developed, as well as the perinatal medical system.

Second trimester maternal serum biomarkers and the risk of cerebral palsy

AIMS

To investigate whether second trimester maternal serum screening (2TMSS) biomarkers are associated with cerebral palsy (CP) and identify CP characteristics associated with abnormal biomarker levels.

METHOD

In this retrospective case-control data linkage study, we linked mothers of 129 singleton CP cases from a population register to their 2TMSS records and selected 10 singleton pregnancy controls per case (n = 1290). We compared mean and abnormal levels of alpha-fetoprotein (AFP), beta subunit of human chorionic gonadotrophin (β-hCG), unconjugated estriol (uE3), and inhibin between cases and controls and within CP subgroups.

RESULTS

Compared to control pregnancies, CP pregnancies had higher mean levels of AFP (1.10 vs. 1.01 multiple of the population median [MoM], p = 0.01) and inhibin (1.10 vs. 0.98 MoM, p ≤ 0.01). CP pregnancies were 2.5 times more likely to be associated with high levels of AFP (OR 2.52 [95% confidence interval [CI] 1.30, 4.65]; p < 0.01) and 2.6 times for inhibin (OR 2.63 [95% CI 1.37, 4.77]; p < 0.01), and 6.8 times when AFP and inhibin were both elevated (OR 6.75 [95% CI 2.41, 18.94]; p < 0.01). In CP cases, high AFP and high inhibin levels were associated with preterm birth and low birthweight.

INTERPRETATION

Abnormal second-trimester biomarker levels suggest abnormal placentation plays a role in the causal pathway of some CP cases.

Congenital anomalies in children with pre- or perinatally acquired cerebral palsy: an international data linkage study

AIM

To describe the frequency and types of major congenital anomalies present in children with pre- or perinatally acquired cerebral palsy (CP), and compare clinical outcomes for children with and without anomalies.

METHOD

This multi-centre total population collaborative study between Surveillance of Cerebral Palsy in Europe, Australian Cerebral Palsy Register, and European Surveillance of Congenital Anomalies (EUROCAT) involved six European and three Australian regions. Data were linked between each region's CP and congenital anomaly register for children born between 1991 and 2009, and then pooled. Children were classified into mutually exclusive categories based on type of anomaly. Proportions of children with congenital anomalies were calculated, and clinical outcomes compared between children with and without anomalies.

RESULTS

Of 8201 children with CP, 22.8% (95% confidence interval [CI] 21.9, 23.8) had a major congenital anomaly. Isolated cerebral anomalies were most common (45.2%), with a further 8.6% having both cerebral and non-cerebral anomalies. Cardiac anomalies only were described in 10.5% of children and anomalies associated with syndromes were also reported: genetic (8.0%), chromosomal (5.7%), and teratogenic (3.0%). Clinical outcomes were more severe for children with CP and congenital anomalies, particularly cerebral anomalies.

INTERPRETATION

This large, international study reports major congenital anomalies in nearly one-quarter of children with pre- or perinatally acquired CP. Future research must focus on aetiological pathways to CP that include specific patterns of congenital anomalies.

WHAT THIS PAPER ADDS

Congenital anomalies were reported in 23% of children with pre- or perinatally acquired cerebral palsy. A higher proportion of children born at or near term had anomalies. The most common type of anomalies were isolated cerebral anomalies. Clinical outcomes were more severe for children with congenital anomalies (particularly cerebral).

Developmental anomalies and associated impairments in Saudi children with cerebral palsy: a registry-based, multicenter study

Background

There are few epidemiological data to support rehabilitation programs for cerebral palsy (CP). Scarce international studies described the developmental anomalies (DAs) among children with CP. To our knowledge, the Arab countries did not publish data regarding this topic. This study aimed to describe the percentage of DAs among children with CP and detect the association between clinical subtypes and impairment severity in children with various DAs. We collected registry data of 679 children with cerebral palsy, between 2014 and 2019, from Armed Forces Hospitals, Taif, Kingdom of Saudi Arabia (KSA). We recorded demographic, perinatal, postnatal, developmental anomalies, subtypes, and impairment characteristics. We utilized the chi-square test to calculate the differences between groups.

Results

We reported significant differences between the children with and without anomalies regarding the percentages of consanguinity, preterm labor, low birth weight, and neonatal intensive care unit admission (P = 0.001, 0.002, 0.003, 0.005, respectively). Congenital dysplasia of the hip and hydrocephalus was the most frequent skeletal and nervous anomalies among children with DAs (19.1% and 12.8%, respectively). The spastic bilateral pattern was significantly higher among children with skeletal anomalies than the central nervous system/other groups (P < 0.001). The nervous anomalies group had higher frequencies of severe intellectual, motor, speech, and visual disabilities and a higher percentage of seizures than all other groups.

Conclusions

The frequency of children with anomalies in this study was comparable to previous studies. Children with CP and nervous system anomalies had more severe motor disabilities and associated impairments.

The Role of Neuroimaging and Genetic Analysis in the Diagnosis of Children With Cerebral Palsy

Cerebral magnetic resonance imaging (MRI) is considered an important tool in the assessment of a child with cerebral palsy (CP), as it is abnormal in more than 80% of children with CP, disclosing the pathogenic pattern responsible for the neurological condition. MRI, therefore, is recommended as the first diagnostic step after medical history taking and neurological examination. With the advances in genetic diagnostics, the genetic contribution to CP is increasingly discussed, and the question arises about the role of genetic testing in the diagnosis of cerebral palsy. The paper gives an overview on genetic findings reported in CP, which are discussed with respect to the underlying brain pathology according to neuroimaging findings. Surveillance of Cerebral Palsy in Europe (SCPE) classifies neuroimaging findings in CP into five categories, which help to stratify decisions concerning genetic testing. Predominant white and gray matter injuries are by far predominant (accounting for around 50 and 20% of the findings). They are considered to be acquired. Here, predisposing genetic factors may play a role to increase vulnerability (and should especially be considered, when family history is positive and/or causative external factors are missing). In maldevelopments and normal findings (around 11% each), monogenic causes are more likely, and thus, genetic testing is clearly recommended. In the miscellaneous category, the precise nature of the MRI finding has to be considered as it could indicate a genetic origin.

Role of child neurologists and neurodevelopmentalists in the diagnosis of cerebral palsy: A survey study

OBJECTIVE

To contextualize the role of child neurologists and neurodevelopmentalists (CNs/NDDs) in cerebral palsy (CP) care, we review the changing landscape of CP diagnosis and survey stakeholder CNs/NDDs regarding their roles in CP care.

METHODS

The optimal roles of the multiple specialties involved in CP care are currently unclear, particularly regarding CP diagnosis. We developed recommendations regarding the role of CNs/NDDs noting (1) increasing complexity of CP diagnosis given a growing number of genetic etiologies and treatable motor disorders that can be misdiagnosed as CP and (2) the views of a group of physician stakeholders (CNs/NDDs from the Child Neurology Society Cerebral Palsy Special Interest Group).

RESULTS

CNs/NDDs felt that they were optimally suited to diagnose CP. Many (76%) felt that CNs/NDDs should always be involved in CP diagnosis. However, 42% said that their patients with CP were typically not diagnosed by CNs/NDDs, and 18% did not receive referrals to establish the diagnosis of CP at all. CNs/NDDs identified areas of their expertise critical for CP diagnosis including knowledge of the neurologic examination across development and early identification of features atypical for CP. This contrasts with their views on CP management, where CNs/NDDs felt that they could contribute to the medical team, but were necessary primarily when neurologic coexisting conditions were present.

DISCUSSION

Given its increasing complexity, we recommend early referral for CP diagnosis to a CN/NDD or specialist with comparable expertise. This contrasts with current consensus guidelines, which either do not address or do not recommend specific specialist referral for CP diagnosis.

Congenital Malformations in Children With Cerebral Palsy: Is Prematurity Protective?

BACKGROUND

Congenital malformations are more common in children who are born prematurely, and prematurity is the leading risk factor for cerebral palsy. The primary objective of this study was to describe the profile of congenital malformations in a Canadian cohort of children with cerebral palsy. The secondary objectives were to compare the profiles of children with cerebral palsy with and without a congenital malformation and explore the possible role of prematurity.

METHODS

This retrospective cohort study utilized data from the Canadian Cerebral Palsy Registry, a population based registry of children with a confirmed diagnosis of cerebral palsy. Differences between groups were compared using Pearson's chi-square and Student t test as appropriate. Odds ratios and 95% confidence intervals were calculated RESULTS: Congenital malformations were present in 23% participants. In term-born children, brain malformations were the most common, whereas heart and gastrointestinal malformations were more common in children born prematurely. Children with a malformation had higher odds of being born at term (odds ratio 1.57, 95% confidence interval 1.20 to 2.04); having hypotonic, ataxic, or dyskinetic cerebral palsy (odds ratio 1.92, 95% confidence interval 1.35 to 2.72; being nonambulatory (odds ratio 1.70, 95% confidence interval 1.29 to 2.25); and having cerebral palsy-associated comorbidities.

CONCLUSIONS

One in four children with cerebral palsy have an associated congenital malformation. Their profile of term birth, higher Apgar scores, and lower frequency of perinatal seizures suggests a distinct causal pathway.

Congenital anomalies in children with cerebral palsy in rural Bangladesh

AIM

To determine the proportion of children with cerebral palsy (CP) who had major congenital anomalies, describe the types of disorders, and report on the children's functional outcomes.

METHOD

Data were extracted from the Bangladesh Cerebral Palsy Register (BCPR). Descriptive analyses were conducted on children with CP and major congenital anomalies. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to measure the association between major congenital anomalies, clinical severity, and presence of comorbidities.

RESULTS

Between January 2015 and December 2016, 726 children with CP were newly registered with the BCPR (277 females, 449 males; mean age [SD] at registration 90mo [54mo], 4mo-18y). Seventy-eight children (11%) had a major congenital anomaly. Neurological (86%) and musculoskeletal congenital anomalies (10%) were the most common. Microcephaly was the most common congenital anomaly (83%). The odds of severe functional motor limitations (OR=2.4, 95% CI=1.9-2.9), epilepsy (OR=1.6, 95% CI=1.1-2.1), visual impairment (OR=2.6, 95% CI=2.0-3.2), presence of strabismus (OR=3.9, 95% CI=3.8-4.4), hearing (OR=1.2, 95% CI=0.6-1.9), speech (OR=5.4, 95% CI=4.6-6.2), and intellectual impairments (OR=2.3, 95% CI=1.8-2.8) were higher in children with congenital anomalies compared to children without.

INTERPRETATION

The proportion of children with major congenital anomalies in the BCPR (11%) was lower than that identified in higher-income countries. This may be because of differences in how congenital anomalies are diagnosed as well as the impact of survival bias. In Bangladesh, children with CP and major congenital anomalies are more likely to have severe functional motor limitations and associated comorbidities.

WHAT THIS PAPER ADDS

Eleven per cent of children with cerebral palsy (CP) in Bangladesh had major congenital anomalies. Neurological and musculoskeletal congenital anomalies were the most common. Severe functional motor limitations and associated comorbidities were more common in children presenting with CP and major congenital anomalies.

Epidemiology of congenital cerebral anomalies in Europe: a multicentre, population-based EUROCAT study

OBJECTIVES

To describe the epidemiology and geographical differences in prevalence of congenital cerebral anomalies in Europe.

DESIGN AND SETTING

Congenital cerebral anomalies (International Classification of Diseases, 10th Revision code Q04) recorded in 29 population-based EUROCAT registries conducting surveillance of 1.7 million births per annum (29% of all European births).

PARTICIPANTS

All birth outcomes (live births, fetal deaths from 20 weeks gestation and terminations of pregnancy after prenatal diagnosis of a fetal anomaly (TOPFA)) from 2005 to 2014.

MAIN OUTCOME MEASURES

Prevalence, proportion of associated non-cerebral anomalies, prenatal detection rate.

RESULTS

4927 cases with congenital cerebral anomalies were identified; a prevalence (adjusted for under-reporting) of 9.8 (95% CI: 8.5 to 11.2) per 10 000 births. There was a sixfold difference in prevalence across the registries. Registries with higher proportions of prenatal diagnoses had higher prevalence. Overall, 55% of all cases were liveborn, 3% were fetal deaths and 41% resulted in TOPFA. Forty-eight per cent of all cases were an isolated cerebral anomaly, 25% had associated non-cerebral anomalies and 27% were chromosomal or part of a syndrome (genetic or teratogenic). The prevalence excluding genetic or chromosomal conditions increased by 2.4% per annum (95% CI: 1.3% to 3.5%), with the increases occurring only for congenital malformations of the corpus callosum (3.0% per annum) and 'other reduction deformities of the brain' (2.8% per annum).

CONCLUSIONS

Only half of the cases were isolated cerebral anomalies. Improved prenatal and postnatal diagnosis may account for the increase in prevalence of congenital cerebral anomalies from 2005 to 2014. However, major differences in prevalence remain between regions.

Congenital Anomalies in Children With Cerebral Palsy: A Systematic Review

Congenital anomalies are a strong risk factor for cerebral palsy, particularly for children born at term. This systematic review aimed to address gaps in our understanding of the association between congenital anomalies and cerebral palsy. Eight population-based studies (n = 10 081) were identified. Congenital anomalies were reported in 12% to 32% of children with pre/perinatal brain injury and 20% of children with postneonatal brain injury. Variation between studies included study cohort inclusion criteria and the definitions and classification of included anomalies. The most common cerebral anomalies were microcephaly and hydrocephaly, whereas circulatory system anomalies were the most common noncerebral anomalies. The proportion of congenital anomalies was higher in children born at term than preterm. Synthesizing the highest quality data published, this review identified that congenital anomalies are common in cerebral palsy. New collaborative research, addressing sources of variation, is vital to identify pathways to cerebral palsy that include specific congenital anomalies, and explore opportunities for prevention.

Ataxic-hypotonic cerebral palsy in a cerebral palsy registry: Insights into a distinct subtype

Objective

To specifically report on ataxic-hypotonic cerebral palsy (CP) using registry data and to directly compare its features with other CP subtypes.

Methods

Data on prenatal, perinatal, and neonatal characteristics and gross motor function (Gross Motor Function Classification System [GMFCS]) and comorbidities in 35 children with ataxic-hypotonic CP were extracted from the Canadian Cerebral Palsy Registry and compared with 1,804 patients with other subtypes of CP.

Results

Perinatal adversity was detected significantly more frequently in other subtypes of CP (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.5-11.7). The gestational age at birth was higher in ataxic-hypotonic CP (median 39.0 weeks vs 37.0 weeks, p = 0.027). Children with ataxic-hypotonic CP displayed more intrauterine growth restriction (OR 2.6, 95% CI 1.0-6.8) and congenital malformation (OR 2.4, 95% CI 1.2-4.8). MRI was more likely to be either normal (OR 3.8, 95% CI 1.4-10.5) or to show a cerebral malformation (OR 4.2, 95% CI 1.5-11.9) in ataxic-hypotonic CP. There was no significant difference in terms of GMFCS or the presence of comorbidities, except for more frequent communication impairment in ataxic-hypotonic CP (OR 4.2, 95% CI 1.5-11.6).

Conclusions

Our results suggest a predominantly genetic or prenatal etiology for ataxic-hypotonic CP and imply that a diagnosis of ataxic-hypotonic CP does not impart a worse prognosis with respect to comorbidities or functional impairment. This study contributes toward a better understanding of ataxic-hypotonic CP as a distinct nosologic entity within the spectrum of CP with its own pathogenesis, risk factors, clinical profile, and prognosis compared with other CP subtypes.

Randomised controlled trial of a novel online cognitive rehabilitation programme for children with cerebral palsy: a study protocol

INTRODUCTION

Cerebral palsy (CP) is the most common cause of physical disability in children, with an estimated 600-700 infants born with CP in Australia each year. CP is typically associated with motor impairments, but nearly half of all children with CP also experience cognitive impairment, potentially impacting educational and vocational achievement. This paper reports the protocol for a randomised controlled trial of a computerised cognitive training intervention based on behavioural principles: Strengthening Mental Abilities through Relational Training (SMART). The study aims to investigate SMART's effect on fluid reasoning, executive function and academic achievement in children with CP.

METHODS AND ANALYSIS

Sixty children with mild to moderate CP (Gross Motor Function Classification Scale I-IV) aged between 8 years and 12 years will be recruited. Participants will be randomly allocated to two groups: SMART cognitive training and waitlist control. Families will access the programme at home over a 4-month period. Assessments will be administered at baseline, 20 weeks and at 40 week follow-up for retention. The primary outcome will be fluid intelligence, while academic achievement, executive function and social and emotional well-being will be secondary outcomes.

ETHICS AND DISSEMINATION

This study has approval from the Children's Health Queensland Hospital and Health Service Research Ethics Committee (HREC/14/QRCH/377) and The University of Queensland (2017001806). If the computerised cognitive training programme is found to be effective, dissemination of these findings would assist children with CP by providing an accessible, cost-effective intervention that can be completed at home at the individual's own pace.

REGISTRATION DETAILS

The study was registered prospectively on 10 November 2017 to present. Recruitment is now under way, and we aim to complete recruitment by June 2019, with data collection finalised by March 2020.

TRIAL REGISTRATION NUMBER

ACTRN12617001550392; Pre-results.

Impact of social disadvantage on cerebral palsy severity

AIM

To investigate the impact of socio-economic disadvantage on indicators of cerebral palsy (CP) severity - motor impairment, intellectual disability, and the presence of severe comorbidities - in children with CP in Australia.

METHOD

Data from the Australian Cerebral Palsy Register were analysed. Socio-economic disadvantage was assessed using maternal age, maternal country of birth, and a measure of neighbourhood socio-economic status (SES) at the time of the child's birth. Descriptive bivariate analysis, trend analysis, risk ratios, and mediation analysis were undertaken to examine the impact of disadvantage on the indicators of CP severity.

RESULTS

A socio-economic gradient was demonstrated with an increasing proportion of children with non-ambulant status, at least moderate intellectual disability, and the presence of severe comorbidities (having epilepsy, functional blindness, bilateral deafness, and/or no verbal communication) with decreasing neighbourhood SES, adolescent motherhood, and maternal minority ethnicity.

INTERPRETATION

In Australia, socio-economic disadvantage at birth impacts adversely on CP severity at age 5 years. By identifying that socio-economically disadvantaged children with CP are at greater risk of more severe functional outcomes, we can inform targeted interventions at the family and neighbourhood level to reduce these inequities for children with CP.

WHAT THIS PAPER ADDS

Socio-economic disadvantage is associated with increased severity of cerebral palsy functional outcomes. This encompasses low neighbourhood socio-economic status, adolescent motherhood, and maternal minority ethnicity.

The complex aetiology of cerebral palsy

Cerebral palsy (CP) is the most prevalent, severe and costly motor disability of childhood. Consequently, CP is a public health priority for prevention, but its aetiology has proved complex. In this Review, we summarize the evidence for a decline in the birth prevalence of CP in some high-income nations, describe the epidemiological evidence for risk factors, such as preterm delivery and fetal growth restriction, genetics, pregnancy infection and other exposures, and discuss the success achieved so far in prevention through the use of magnesium sulfate in preterm labour and therapeutic hypothermia for birth-asphyxiated infants. We also consider the complexities of disentangling prenatal and perinatal influences, and of establishing subtypes of the disorder, with a view to accelerating the translation of evidence into the development of strategies for the prevention of CP.

Congenital brain malformations in Sudanese children: an outpatient-based study

Congenital brain malformations (CBMs) are a heterogeneous group characterised by abnormal structure of the developing brain. Their aetiology includes in-utero infections, teratogenicity and in a considerable group, genetic causes. Due to the high rate of consanguineous marriages and the possible high prevalence of prenatal infections in Sudan, CBMs are likely to be common. The main aim of this study was to review the clinical profile of children with CBMs attending two main tertiary paediatrics neurology outpatient clinics in Khartoum State, Sudan. Children under the age of 18 years who presented with developmental delay, seizures or abnormal head size were evaluated clinically and with neuroimaging for possible CBMs. Out of 2,114 patients seen within 6 months (September 2016-March 2017) at the Outpatient Departments, 105 patients (5%) were diagnosed with CBMs. Sixty patients (57.1%) had a single brain anomaly, 36 patients (34.1%) had two brain anomalies while nine patients (8.6%) had multiple brain anomalies. Collectively, cortical malformations either isolated or in combination with other anomalies were observed in 37 patients (35.1%), thus by representing the commonest CBMs. Community-based epidemiological studies are needed to ascertain CBMs prevalence, common causes and long-term outcomes.

Comprehensive investigation of congenital anomalies in cerebral palsy: protocol for a European-Australian population-based data linkage study (The Comprehensive CA-CP Study)

INTRODUCTION

Cerebral palsy (CP), an umbrella term for non-progressive conditions of cerebral origin resulting in motor impairments, is collectively the most common cause of physical disability in childhood. Cerebral and/or non-cerebral congenital anomalies are present in 15%-40% of children with CP. In order to identify effective prevention strategies for this substantial proportion of CP, a comprehensive understanding of the epidemiology of these congenital anomalies is required. International collaboration is needed, as previous attempts have fallen short due to a lack of power, since the anomalies are individually rare and CP comprises many clinical descriptions. The aim of this study is to generate new knowledge about the aetiologies of CP through a focused investigation into the role of congenital anomalies.

METHODS AND ANALYSIS

This collaborative, population-based data linkage study includes nine geographic regions (six in Europe, three in Australia) served by both congenital anomaly and CP registers. Register data for children with CP (both with and without congenital anomalies) and children with specific congenital anomalies (without CP) born between 1991 and 2009 will be linked and de-identified within each region. The resulting linked data sets will be quality assured, recoded, harmonised and then pooled into one data set. Analysis of the combined data set will include: frequencies/proportions of congenital anomalies and outcomes (type of CP, severity, impairments); descriptive analyses comparing timing of congenital anomaly development and brain injury/abnormality responsible for CP; ORs to calculate the odds of CP following a specific congenital anomaly; and identification of anomalies on causal pathways to CP.

ETHICS AND DISSEMINATION

Ethics approval for this collaborative study, The Comprehensive CA-CP Study, has been obtained from the Cerebral Palsy Alliance Human Research Ethics Committee (EC00402). Study findings will be disseminated at conferences and published in peer-reviewed journals, and recommendations will be made regarding the collection and classification of congenital anomaly data by CP registers.

Cryptorchidism in Boys With Cerebral Palsy Is Associated With the Severity of Disease and With Co-Occurrence of Other Congenital Anomalies

BACKGROUND

Cryptorchidism is reported in 40-50% of small case series of cerebral palsy (CP) and attributed to hypothalamic-pituitary-gonadal axis abnormalities, intellectual disability (ID), or cremaster spasticity. We collected demographic and clinical data to define the frequency of cryptorchidism and clinical comorbidities in a large CP population.

METHODS

Electronic health record data were collected for all male patients ≥7 years of age seen in a large, multidisciplinary CP clinic between 2000 and 2016. Variables including age, testicular position, surgical findings, CP severity, birth history, and comorbidities were tested for association using univariable and stepwise backward logistic regression analyses.

RESULTS

Of 839 established patients, testis position was scrotal in 553, undescended in 185 (24%), retractile in 38 (5%), and undocumented in 63 cases. Cryptorchidism were diagnosed at a mean age of 5.8 years, with 20% documented as acquired, and testes were most commonly in the superficial inguinal pouch (41%) and associated with an inguinal hernia (56%). Severity was bilateral in 114/166 (69%) undescended and 24/36 (66%) retractile cases, respectively. Mean birth weight and the frequency of prematurity (55, 58, and 54%) and multiple birth (14, 13, and 9%) were not significantly different among the three groups. We observed a strong ordinal trend in the frequency of comorbidities, including quadriplegia, syndromic features/known genetic disease, intrauterine growth restriction (IUGR), death, brain malformations, seizures, gastrostomy, absent continence, ID and hearing, speech or visual impairment, with the retractile group holding the intermediate position for the majority. The stepwise multivariable analysis showed independent positive associations of cryptorchidism with quadriplegia, syndromic features/known genetic disease, hearing loss, and absent continence, and inverse associations with gestational age and multiple birth.

CONCLUSION

These data suggest that cryptorchidism is less common than previously reported in CP cases, but most strongly associated with quadriplegia. Delayed diagnosis may be related to an acquired condition or to the multiple additional functional deficits that occur in this population. Our data suggest that UDT and CP may both be components of malformation syndromes occurring in singleton births whose clinical features are more likely to include earlier delivery, IUGR, hearing loss, and/or global spasticity.

Congenital anomalies and the severity of impairments for cerebral palsy

AIM

To study the prevalence of congenital anomalies among children with cerebral palsy (CP) born at term or late preterm, and if CP subtypes and clinical manifestations differ between children with and without congenital anomalies.

METHOD

This was a cross-sectional study using data from the Cerebral Palsy Register of Norway and the Medical Birth Registry of Norway. All children with congenital CP born at and later than 34 weeks' gestation in Norway from 1999 to 2009 were included. Anomalies were classified according to the European Surveillance of Congenital Anomalies classification guidelines. Groups were compared using Fisher's exact test, Kruskal-Wallis test, and the Mann-Whitney U test.

RESULTS

Among 685 children with CP, 169 (25%) had a congenital anomaly; 125 within the central nervous system. Spastic bilateral CP was more prevalent in children with anomalies (42%) than in children without (34%; p=0.011). Children with anomalies less frequently had low Apgar scores (p<0.001), but more often had severe limitations in gross- and fine-motor function, speech impairments, epilepsy, severe vision, and hearing impairments than children without anomalies (p<0.03).

INTERPRETATION

Although children with CP and anomalies had low Apgar scores less frequently, they had more severe limitations in motor function and more associated problems than children with CP without anomalies.

WHAT THIS PAPER ADDS

One in four children with cerebral palsy (CP) born at term or late preterm has a congenital anomaly. The added value of neuroimaging to detect central nervous system anomalies in children with CP. Children with anomalies have more severe motor impairments. More severe clinical manifestations are not explained by perinatal complications as indicated by low Apgar scores.

Cerebral Palsy-Trends in Epidemiology and Recent Development in Prenatal Mechanisms of Disease, Treatment, and Prevention

Cerebral palsy (CP) is the most common motor disability in childhood. This syndrome is the manifestation of intrauterine pathologies, intrapartum complications, and the postnatal sequel, especially among preterm neonates. A double hit model theory is proposed suggesting that an intrauterine condition along with intrapartum or postnatal insult lead to the development of CP. Recent reports demonstrated that treatment during the process of preterm birth such as magnesium sulfate and postnatal modalities such as cooling may prevent or reduce the prevalence of this syndrome. Moreover, animal models demonstrated that postnatal treatment with anti-inflammatory drugs coupled with nanoparticles may affect the course of the disease in pups with neuroinflammation. This review will describe the changes in the epidemiology of this disease, the underlying prenatal mechanisms, and possible treatments that may reduce the prevalence of CP and alter the course of the disease.

Volumetric Magnetic Resonance Imaging Study of Brain and Cerebellum in Children with Cerebral Palsy

Introduction. Quantitative magnetic resonance imaging (MRI) studies are rarely used in the diagnosis of patients with cerebral palsy. The aim of present study was to assess the relationships between the volumetric MRI and clinical findings in children with cerebral palsy compared to control subjects. Materials and Methods. Eighty-two children with cerebral palsy and 90 age- and sex-matched healthy controls were collected. Results. The dominant changes identified on MRI scans in children with cerebral palsy were periventricular leukomalacia (42%) and posthemorrhagic hydrocephalus (21%). The total brain and cerebellum volumes in children with cerebral palsy were significantly reduced in comparison to controls. Significant grey matter volume reduction was found in the total brain in children with cerebral palsy compared with the control subjects. Positive correlations between the age of the children of both groups and the grey matter volumes in the total brain were found. Negative relationship between width of third ventricle and speech development was found in the patients. Positive correlations were noted between the ventricles enlargement and motor dysfunction and mental retardation in children with cerebral palsy. Conclusions. By using the voxel-based morphometry, the total brain, cerebellum, and grey matter volumes were significantly reduced in children with cerebral palsy.

Antecedents of cerebral palsy according to severity of motor impairment

INTRODUCTION

The purpose of this study was to determine whether antecedents and neuroimaging patterns vary according to the severity of motor impairment in children with cerebral palsy.

MATERIAL AND METHODS

A population-based study in which all 309 term-born children with spastic and dyskinetic cerebral palsy born between 1983 and 1994 and 618 matched controls were studied. Antecedents were retrieved from obstetric records. Information on neuroimaging was retrieved from the cerebral palsy Register of Western Sweden. Cases were grouped by severity of motor impairment: mild (walks without aids), moderate (walks with aids) or severe (dependent on wheelchair). Binary logistic regression, the Cochran-Armitage test for trends, interaction analyses and interrelationship analyses were performed.

RESULTS

Antecedents associated with mild motor impairment were antepartum (placental weight, maternal weight and antibiotic therapy) or intrapartum and postpartum adverse events (meconium-stained amniotic fluid, low Apgar score, admission to neonatal intensive care unit and neonatal encephalopathy). Antecedents associated with severe motor impairment were antepartum (congenital infection, small head circumference and brain maldevelopment) or intrapartum and postpartum (emergency cesarean section and maternal antibiotic therapy). Comparisons between mild and severe motor impairment revealed congenital infection, maldevelopment, neonatal encephalopathy and meconium aspiration syndrome significantly more often in the group with severe motor impairment (p < 0.05). White matter injury was the most common neuroimaging pattern in mild motor impairment, whereas maldevelopment and cortical/subcortical lesions were most common in the severe motor impairment group.

CONCLUSIONS

Our results suggest a variation in antecedents associated with cerebral palsy, related to severity of motor impairment. Timing of antecedents corresponded to neuroimaging patterns.

Congenital anomalies in cerebral palsy: where to from here?

Proportions of cases of cerebral palsy (CP) with congenital anomalies recorded in Australian CP registers range from 15% to 40%. The anomalies seen in CP are extremely variable. We have identified that CP registers often do not have quality data on congenital anomalies, necessitating linkage with congenital anomaly registers. However, a lack of unified processes and definitions in congenital anomaly registers and data collections means that linkages are complex, need to be carefully planned, and limitations acknowledged. Historically in CP research, congenital anomalies have been classified by International Classification of Disease codes, then combined into brain and other major and minor anomalies. Systems have been developed to classify congenital anomalies into aetiologically related groups, but such a classification has yet to be trialled in CP. It is anticipated that primary prevention of a small proportion of cases of CP is possible through the primary prevention of congenital anomalies, especially those due to teratogens. Owing to the anticipated low prevalence of each subgroup, global collaboration will be required to further these lines of enquiry.

Systematic Review of Cerebral Palsy Registries/Surveillance Groups: Relationships between Registry Characteristics and Knowledge Dissemination

The aims of this study were to provide a comprehensive summary of the body of research disseminated by Cerebral Palsy (CP) registries and surveillance programs from January 2009 through May 2014 in order to describe the influence their results have on our overall understanding of CP. Secondly, registries/surveillance programs and the work they produced were evaluated and grouped using standardized definitions and classification systems.

METHOD

A systematic review search in PubMed, CINAH and Embase for original articles published from 1 January 2009 to 20 May 2014 originating from or supported by population based CP registries and surveillance programs or population based national registries including CP were included. Articles were grouped by 2009 World CP Registry Congress aim, registry/surveillance program classification, geographical region, and the International Classification of Function, Disability and Health (ICF) domain. Registry variables were assessed using the ICF-CY classification.

RESULTS

Literature searches returned 177 articles meeting inclusion criteria. The majority (69%) of registry/surveillance program productivity was related to contributions as a Resource for CP Research. Prevention (23%) and Surveillance (22%) articles were other areas of achievement, but fewer articles were published in the areas of Planning (17%) and Raising the Profile of CP (2%). There was a range of registry/surveillance program classifications contributing to this productivity, and representation from multiple areas of the globe, although most of the articles originated in Europe, Australia, and Canada. The domains of the ICF that were primarily covered included body structures and function at the early stages of life. Encouragingly, a variety of CP registry/surveillance program initiatives included additional ICF domains of participation and environmental and personal factors.

INTERPRETATION

CP registries and surveillance programs, including novel non-traditional ones, have significantly contributed to the understanding of how CP affects individuals, families and society. Moving forward, the global CP registry/surveillance program community should continue to strive for uniformity in CP definitions, variables collected and consistency with international initiatives like the ICF so that databases can be consolidated for research use. Adaptation to new technologies can improve access, reduce cost and facilitate information transfer between registrants, researchers and registries/surveillance programs. Finally, increased efforts in documenting variables of individuals with CP into adulthood should be made in order to expand our understanding of CP across the lifespan.

A diagnostic approach for cerebral palsy in the genomic era

An ongoing challenge in children presenting with motor delay/impairment early in life is to identify neurogenetic disorders with a clinical phenotype, which can be misdiagnosed as cerebral palsy (CP). To help distinguish patients in these two groups, conventional magnetic resonance imaging of the brain has been of great benefit in "unmasking" many of these genetic etiologies and has provided important clues to differential diagnosis in others. Recent advances in molecular genetics such as chromosomal microarray and next-generation sequencing have further revolutionized the understanding of etiology by more precisely classifying these disorders with a molecular cause. In this paper, we present a review of neurogenetic disorders masquerading as cerebral palsy evaluated at one institution. We have included representative case examples children presenting with dyskinetic, spastic, and ataxic phenotypes, with the intent to highlight the time-honored approach of using clinical tools of history and examination to focus the subsequent etiologic search with advanced neuroimaging modalities and molecular genetic tools. A precise diagnosis of these masqueraders and their differentiation from CP is important in terms of therapy, prognosis, and family counseling. In summary, this review serves as a continued call to remain vigilant for current and other to-be-discovered neurogenetic masqueraders of cerebral palsy, thereby optimizing care for patients and their families.

Cerebral palsy

The syndrome of cerebral palsy encompasses a large group of childhood movement and posture disorders. Severity, patterns of motor involvement, and associated impairments such as those of communication, intellectual ability, and epilepsy vary widely. Overall prevalence has remained stable in the past 40 years at 2-3·5 cases per 1000 livebirths, despite changes in antenatal and perinatal care. The few studies available from developing countries suggest prevalence of comparable magnitude. Cerebral palsy is a lifelong disorder; approaches to intervention, whether at an individual or environmental level, should recognise that quality of life and social participation throughout life are what individuals with cerebral palsy seek, not improved physical function for its own sake. In the past few years, the cerebral palsy community has learned that the evidence of benefit for the numerous drugs, surgery, and therapies used over previous decades is weak. Improved understanding of the role of multiple gestation in pathogenesis, of gene environment interaction, and how to influence brain plasticity could yield significant advances in treatment of the disorder. Reduction in the prevalence of post-neonatal cerebral palsy, especially in developing countries, should be possible through improved nutrition, infection control, and accident prevention.

Mining Association Rules for Neurobehavioral and Motor Disorders in Children Diagnosed with Cerebral Palsy

Children diagnosed with cerebral palsy (CP) appear to be at high risk for developing neurobehavioral and motor disorders. The most common disorders for these children are impaired visual-perception skills and motor planning. Besides, they often have impaired executive functions, which can contribute to problematic emotional adjustment such as depression. Additionally, literature suggests that the tendency to develop these cognitive impairments and emotional abnormalities in pediatric CP is influenced by age and IQ. Because there are many other medical co-morbidities that can occur with CP (e.g., seizures and shunt placement), prediction of what percentages of patients will incur cognitive impairment and emotional abnormality is a difficult task. The purpose of this study was to investigate the associations between possible factors mentioned above, and neurobehavioral and motor disorders from a clinical database of pediatric subjects diagnosed with CP. The study resulted in 22 rules that can predict negative outcomes. These rules reinforced the growing body of literature supporting a link between CP, executive dysfunction, and subsequent neurobehavioral problems. The antecedents and consequents of some association rules were single factors, while other statistical associations were interactions of factor combinations. Further research is needed to include children's comprehensive treatment and medication history in order to determine additional impacts on their neurobehavioral and motor disorders.

Clinical prognostic messages from a systematic review on cerebral palsy

OBJECTIVE

To summarize evidence on the rates of co-occurring impairments, diseases, and functional limitations with cerebral palsy into succinct clinical messages.

METHODS

A search was conducted of the databases PubMed, Medline, CINAHL, and PsycINFO, and the results were supplemented with hand searches. Two independent reviewers determined whether retrieved abstracts met the following inclusion criteria: human subjects; >90% were children or adults with cerebral palsy; published after 1999; and population-based data. Articles were appraised, analyzing design, participants, level of evidence, rates of impairments, and functional implications. Methodologic quality was rated by using a standardized checklist.

RESULTS

A total of 1366 papers were identified in the search; 82 were appraised and 30 were included in the meta-analyses. High-level evidence existed, as rated on the Oxford 2011 LEVELS OF EVIDENCE: 97% of prevalence studies were level 1. The data were of a moderate to high quality grade (with the exception of sleep disorders), allowing plain English clinical messages to be developed.

CONCLUSIONS

Among children with cerebral palsy, 3 in 4 were in pain; 1 in 2 had an intellectual disability; 1 in 3 could not walk; 1 in 3 had a hip displacement; 1 in 4 could not talk; 1 in 4 had epilepsy; 1 in 4 had a behavior disorder; 1 in 4 had bladder control problems; 1 in 5 had a sleep disorder; 1 in 5 dribbled; 1 in 10 were blind; 1 in 15 were tube-fed; and 1 in 25 were deaf.

Congenital non-central nervous system malformations in cerebral palsy: a distinct subset?

AIM

The aim of this article was to identify and contrast the subset of children with cerebral palsy (CP) and non-central nervous system (CNS) congenital malformations with children with CP but no coexisting non-CNS congenital malformations.

METHOD

A population-based regional comprehensive CP registry was used to identify children with CP who had non-CNS congenital malformations (n = 34; 19 males, 15 females; 22 classified as Gross Motor Function Classification System [GMFCS] levels I-III, 12 as GMFCS level IV or V). Their clinical features were then compared with other children with CP without non-CNS congenital malformations (n = 207; 115 males, 92 females; 138 classified as GMFCS levels I-III, 69 as GMFCS level IV or V).

RESULTS

Children with CP and non-CNS congenital malformations did not differ from those without in terms of neurological subtype distribution or functional severity, as measured by the GMFCS. Also, there was no association with previous maternal infections (i.e. toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus 2 [TORCH]), maternal fever, use of illicit substances, asphyxia, neonatal encephalopathy, intraventricular haemorrhage, or septicaemia. The incidence of comorbidities such as convulsions, communication difficulties, gavage feeding, cortical blindness, and auditory impairment was not higher in this subgroup.

INTERPRETATION

The incidence of congenital non-CNS malformations among children with CP is appreciable. Children with these non-CNS malformations do not appear to differ from other children with CP regarding neurological subtype, functional severity, and comorbidities, or maternal or obstetrical factors. Thus, the specific presence of a non-CNS congenital malformation does not appear to assist the practitioner in the management or understanding of a child's CP.

De novo mutations in the actin genes ACTB and ACTG1 cause Baraitser-Winter syndrome

Brain malformations are individually rare but collectively common causes of developmental disabilities^1–3. Many forms occur sporadically and have reduced reproductive fitness, pointing towards a causative role for de novo mutations^4,5. Here we report our studies of Baraitser-Winter syndrome, a well-defined syndrome characterized by distinct craniofacial features, ocular colobomata and a neuronal migration defect^6,7. By using whole-exome sequencing in three proband-parent trios, we identified de novo missense changes in the cytoplasmic actin genes ACTB and ACTG1 in one and two probands, respectively. Sequencing of both genes in fifteen additional patients revealed disease-causing mutations in all probands, including two recurrent de novo mutations (ACTB p.Arg196His and ACTG1 p.Ser155Phe). Our results confirm that trio-based exome sequencing is a powerful approach to discover the genes causing sporadic developmental disorders, emphasize the overlapping roles of cytoplasmic actins in development, and suggest that Baraitser-Winter syndrome is the predominant phenotype associated with mutations of these two genes.

Genetic [corrected] insights into the causes and classification of [corrected] cerebral palsies

Cerebral palsy-the most common physical disability of childhood-is a clinical diagnosis encompassing a heterogeneous group of neurodevelopmental disorders that cause impairments of movement and posture that persist throughout life. Despite being commonly attributed to a range of environmental factors, particularly birth asphyxia, the specific cause of cerebral palsy remains unknown in most individuals. A growing body of evidence suggests that cerebral palsy is probably caused by multiple genetic factors, similar to other neurodevelopmental disorders such as autism and intellectual disability. Recent advances in next-generation sequencing technologies have made possible rapid and cost-effective sequencing of the entire human genome. Novel cerebral palsy genes will probably be identified as more researchers and clinicians use this approach to study individuals with undiagnosed neurological disorders. As our knowledge of the underlying pathophysiological mechanisms of cerebral palsy increases, so will the possibility of developing genomically guided therapeutic interventions.

Adaptor protein complex-4 (AP-4) deficiency causes a novel autosomal recessive cerebral palsy syndrome with microcephaly and intellectual disability

BACKGROUND

Cerebral palsy is a heterogeneous group of neurodevelopmental brain disorders resulting in motor and posture impairments often associated with cognitive, sensorial, and behavioural disturbances. Hypoxic-ischaemic injury, long considered the most frequent causative factor, accounts for fewer than 10% of cases, whereas a growing body of evidence suggests that diverse genetic abnormalities likely play a major role.

METHODS AND RESULTS

This report describes an autosomal recessive form of spastic tetraplegic cerebral palsy with profound intellectual disability, microcephaly, epilepsy and white matter loss in a consanguineous family resulting from a homozygous deletion involving AP4E1, one of the four subunits of the adaptor protein complex-4 (AP-4), identified by chromosomal microarray analysis.

CONCLUSION

These findings, along with previous reports of human and mouse mutations in other members of the complex, indicate that disruption of any one of the four subunits of AP-4 causes dysfunction of the entire complex, leading to a distinct 'AP-4 deficiency syndrome'.

Cerebral palsy among term and postterm births

CONTEXT

Although preterm delivery is a well-established risk factor for cerebral palsy (CP), preterm deliveries contribute only a minority of affected infants. There is little information on the relation of CP risk to gestational age in the term range, where most CP occurs.

OBJECTIVE

To determine whether timing of birth in the term and postterm period is associated with risk of CP.

DESIGN, SETTING, AND PARTICIPANTS

Population-based follow-up study using the Medical Birth Registry of Norway to identify 1,682,441 singleton children born in the years 1967-2001 with a gestational age of 37 through 44 weeks and no congenital anomalies. The cohort was followed up through 2005 by linkage to other national registries.

MAIN OUTCOME MEASURES

Absolute and relative risk of CP for children surviving to at least 4 years of age.

RESULTS

Of the cohort of term and postterm children, 1938 were registered with CP in the National Insurance Scheme. Infants born at 40 weeks had the lowest risk of CP, with a prevalence of 0.99/1000 (95% confidence interval [CI], 0.90-1.08). Risk for CP was higher with earlier or later delivery, with a prevalence at 37 weeks of 1.91/1000 (95% CI, 1.58-2.25) and a relative risk (RR) of 1.9 (95% CI, 1.6-2.4), a prevalence at 38 weeks of 1.25/1000 (95% CI, 1.07-1.42) and an RR of 1.3 (95% CI, 1.1-1.6), a prevalence at 42 weeks of 1.36/1000 (95% CI, 1.19-1.53) and an RR of 1.4 (95% CI, 1.2-1.6), and a prevalence after 42 weeks of 1.44 (95% CI, 1.15-1.72) and an RR of 1.4 (95% CI, 1.1-1.8). These associations were even stronger in a subset with gestational age based on ultrasound measurements: at 37 weeks the prevalence was 1.17/1000 (95% CI, 0.30-2.04) and the relative risk was 3.7 (95% CI, 1.5-9.1). At 42 weeks the prevalence was 0.85/1000 (95% CI, 0.33-1.38) and the relative risk was 2.4 (95% CI, 1.1-5.3). Adjustment for infant sex, maternal age, and various socioeconomic measures had little effect.

CONCLUSION

Compared with delivery at 40 weeks' gestation, delivery at 37 or 38 weeks or at 42 weeks or later was associated with an increased risk of CP.