The effects of multiple pre- and perinatal risk factors on the occurrence of cerebral palsy. A Norwegian register based study

Association Between Assisted Reproductive Technology and Cerebral Palsy: A Meta-Analysis

BACKGROUND

Since 1978 many children are born thanks to assisted reproductive technology (ART). However, the long-term effects of these therapies are still not fully known. Our objective is to evaluate the risk of cerebral palsy (CP) after ART compared with that in those spontaneously conceived (SC) and to examine this risk in single, multiple, and preterm births and the evolution of the risk over the years.

METHODS

PubMed, Embase, and Web of Science databases were searched until December 2022. Studies were included if they studied CP cases in children born through ART. 16 studies were finally selected. Quality of studies was assessed using Newcastle Ottawa Scale. Pooled OR was estimated by weighting individual OR/RR by the inverse of their variance. A random-effect model was applied. To assess the causes of heterogeneity, we performed meta-regression analyses.

RESULTS

A significantly high risk of CP was found (OR = 1.27; 95% CI 1.12 to 1.43) in children born through ART compared with those SC. This risk increased in singletons (OR = 1.48; 95% CI 1.23 to 1.79) but disappeared in multiple (OR = 1.05; 95% CI 0.93 to 1.18) and preterm births (OR = 1.09; 95% CI 0.87 to 1.37). We found a higher risk of CP in children born before the year 2000 (OR = 3.40; 95% CI 2.49 to 4.63).

CONCLUSIONS

ARTs slightly increase the risk of CP once the effect of multiple gestation is controlled. Further studies are needed to clarify whether the techniques themselves, fertility problems, or associated maternal comorbidities are responsible for this risk.

Cumulative Prenatal Risk Factors and Developmental Coordination Disorder in Young Children

OBJECTIVES

To examine the effect of cumulative prenatal risk factors (RFs) on the presence of Developmental Coordination Disorder (DCD) in young children.

METHODS

Participants (N = 589, 338 boys, Mage = 4.5 ± 0.5 years) were from a larger cohort study, the Coordination and Activity Tracking in Children (CATCH). Motor coordination was assessed using the Movement Assessment Battery for Children- 2nd Edition. Children were classified as at risk for DCD (DCDr) based on European Academy of Childhood Disability guidelines. RFs were obtained through a parent-completed survey. A multiple logistic regression was conducted to examine the effect of the RFs on DCD.

RESULTS

Results showed that the odds of a child having DCDr are significantly higher with a greater total number of prenatal RFs, after adjustment for mother's age at child's birth, child's sex, child's age, marital status and total annual household income (OR = 1.48, p < 0.01).

CONCLUSIONS

These findings warrant further investigation into the cumulative impact of multiple prenatal RFs and whether specific combinations of RFs might be more strongly linked to DCD than others. These results provide additional insight into possible causes and prevention of DCD.

The effect of gestational age on major neurodevelopmental disorders in preterm infants

BACKGROUND

Preterm infants have an increased risk of neurodevelopmental disorders. We established a direct quantitative comparison of the association between the degree of prematurity and three different neurodevelopmental disorders.

METHODS

In this cohort study, we combined data from 995,498 children in the Danish Medical Birth Register, from birth years 1997-2013, with information on cerebral palsy, epilepsy, and special educational needs. We estimated the gestational week-specific prevalence and risk for each of the disorders.

RESULTS

The risk ratio of cerebral palsy at gestational weeks 21-24, compared to term birth, was more than ten times higher than for the two other disorders. The prevalence of epilepsy and special educational needs declined almost parallel, with 9.2% (4.6%-13.5%) and 12.5% (11.2%-13.7%), respectively, per week of gestation toward term birth. Cerebral palsy did not decline similarly: from gestational weeks 21-24 until week 29 the prevalence declined insignificantly by 0.6% (-11.1%-11.0%) per week; whereas from week 29 until term, the prevalence declined markedly by 36.7% (25.9%-45.9%) per week.

CONCLUSIONS

The prevalence and risk of cerebral palsy are affected differently by the degree of prematurity compared with epilepsy and special educational needs, possibly reflecting important differences in cerebral pathophysiology.

IMPACT

For each week of gestation toward term birth, there was a clear log-linear decline in the prevalence of early childhood epilepsy and special educational needs. In contrast, the risk of cerebral palsy was high at the earliest gestational age, and the prevalence did not decline significantly until gestational week 29, from where it declined notably by nearly 40% for each week of gestation until term birth. Our results indicate important differences in the pathophysiological processes that associate preterm birth with these three neurodevelopmental disorders.

Cerebral palsy in children born after assisted reproductive technology: a meta-analysis

BACKGROUND

Several studies have assessed the association between cerebral palsy (CP) and assisted reproductive technology (ART), but the results remain controversial. We conducted a meta-analysis to evaluate the risk of CP after ART compared with natural conceptions and to examine CP risk separately in ART singletons, multiples and preterm births.

METHODS

Web-based databases (PubMed, Embase, the Cochrane Library, and Web of Science) were searched until November 22, 2020. Studies which compare CP rates after ART with natural conceptions were included. The Newcastle-Ottawa Scale was used to assess the quality of the included studies. Effect estimates were extracted and combined using the fixed-effects or random-effects model depending on the heterogeneity test.

RESULTS

There were nine studies included in the meta-analysis. The included studies were of moderate or high quality. A significantly higher risk of CP [odds ratio (OR) = 2.17, 95% confidence interval (CI) 1.72-2.74] was found in ART children (n = 89,214) compared with naturally conceived children (n = 4,160,745). The significantly higher risk decreased when data were restricted to singletons (OR = 1.36, 95% CI 1.16-1.59) and disappeared when data were restricted to multiples (OR = 1.05, 95% CI 0.86-1.29) or preterm births (OR = 1.53, 95% CI 0.66-3.56). Subgroup and sensitivity analyses indicated that the overall results were robust.

CONCLUSIONS

The risk of CP is increased more than two-fold after ART. This increased risk is largely due to increased rates of multiple birth and preterm delivery in ART children.

Risk Factors for Cerebral Palsy in Moldova

Background and Objectives: This is the first study assessing risk factors for cerebral palsy (CP) among children born in Moldova. The aim of this study was to identify and describe risk factors for cerebral palsy (CP) among children born in Moldova, which is one of the low-middle income countries in Europe. Materials and Methods: We identified 351 children with CP born during 2009 and 2010 in Moldova. Detailed information on 417 children without CP served as a reference group. Logistic regression analyses were applied to the calculate crude and adjusted odds ratios (OR) for CP with 95% confidence intervals (CI) in addition to attributable fraction (AF). Results: Among children with CP (40.5% girls), 26% had spastic unilateral, 54% bilateral, 13% dyskinetic, 5% ataxic and 2% unclassified CP. Significant risk factors for CP included maternal alcohol consumption during pregnancy (OR 1.7, p = 0.002), maternal hypertension (OR 2.0, p < 0.001), children born to mothers from the rural areas (OR 1.6, p < 0.001), maternal age ≥35 years (OR 0.6, p = 0.018), maternal epilepsy (OR 4.3, p < 0.001), breech delivery (OR 3.1, p = 0.001), home births (OR 6.3, p = 0.001), umbilical cord around neck (OR 2.2, p < 0.001), AVD (OR 3.1, p < 0.001), male gender (OR 1.3, p < 0.001), SGA (OR 1.3, p = 0.027), multiple gestations (OR 1.7, p < 0.001) and hyperbilirubinemia (OR 4.5, p < 0.001). Multivariable analyses showed that the AF of CP was 64% for rural residence (OR 2.8, p = 0.002), 87% for home birth (7.6, p = 0.005), 79% for pre-labor rupture of membrane (OR 4.9, p = 0.001), 66% for breech delivery (OR 2.9, p = 0.002) and 81% for hyperbilirubinemia (OR 5.4, p < 0.001). Conclusions: A combination of factors related to the mother, the delivery and the child were risk factors for CP in Moldova, many of them possibly avoidable. Improved pregnancy and maternity care would potentially reduce the risk of CP. A national CP registry in Moldova is suggested as an opportunity to follow up on these findings.

Maternal Chronic Conditions and Risk of Cerebral Palsy in Offspring: A National Cohort Study

BACKGROUND AND OBJECTIVES

Previous studies suggest that children of mothers with certain chronic conditions may be at increased risk of cerebral palsy (CP). We explored possible associations between 17 maternal chronic conditions and CP in offspring.

METHODS

We conducted a prospective cohort study of Norwegian children born in 1990-2012 and surviving to 2 years of age. Information on maternal chronic conditions during pregnancy were extracted from the Medical Birth Registry of Norway (1990-2012). Information on chronic conditions in mothers and fathers recorded in the Norwegian Patient Registry (2008-2014) was available for a subset of children. CP diagnoses were extracted from the National Insurance Scheme (1990-2014) and the Norwegian Patient Registry (2008-2014). We estimated relative risks (RRs) and 95% confidence intervals (CIs) of CP in offspring of parents with chronic conditions compared with the general population using log binominal regression models.

RESULTS

A total of 1 360 149 Norwegian children, including 3575 children with CP (2.6 per 1000 live births), fulfilled the inclusion criteria. The highest risk of CP was among offspring of mothers with type 2 diabetes (RR 3.2; 95% CI 1.8-5.4), lupus erythematosus (RR 2.7; 95% CI 0.9-8.3), type 1 diabetes (RR 2.2; 95% CI 1.4-3.4), and Crohn disease (RR 2.1; 95% CI 1.0-4.1) during pregnancy. No increased risks were seen for offspring of fathers with chronic conditions.

CONCLUSIONS

Several maternal chronic conditions were associated with increased risk of CP in offspring. Maternal autoimmune disorders carried a particular risk.

Cost effectiveness of buprenorphine vs. methadone for pregnant people with opioid use disorder

OBJECTIVE

To assess the cost effectiveness of buprenorphine versus methadone in the management of opioid use disorder (OUD) during pregnancy.

METHODS

We designed a decision-analytic model to evaluate the costs and outcomes associated with buprenorphine compared to methadone for pregnant people with OUD. We used a theoretical cohort of 22,400 pregnant people, which is an estimation of pregnancies affected by OUD per year in the United States. Outcomes included maternal retention in maintenance treatment, neonatal opioid withdrawal syndrome, preterm birth, fetal growth restriction, cerebral palsy, and maternal overdose in addition to cost and quality-adjusted life-years (QALYs). We used a willingness-to-pay threshold of $100,000/QALY. All model inputs were derived from the literature and varied in sensitivity analyses to assess the robustness of our baseline inputs.

RESULTS

In our theoretical cohort, treatment of OUD with buprenorphine during pregnancy resulted in 2413 fewer cases of neonatal opioid withdrawal syndrome, 1089 fewer preterm births, 299 fewer cases of fetal growth restriction, 32 fewer stillbirths, and 13 fewer cases of cerebral palsy compared to methadone treatment. Despite lower rates of retention, buprenorphine treatment saved nearly 123 million healthcare dollars and resulted in 558 additional QALYs, making it the dominant strategy compared to methadone treatment. Our findings were robust over a wide range of assumptions.

CONCLUSION

Our data suggest that buprenorphine should be considered a cost effective treatment option for OUD in pregnancy, as it is associated with improved neonatal outcomes compared to methadone despite the risk of treatment discontinuation.

Does caesarean delivery in the first pregnancy increase the risk for adverse outcome in the second? A registry-based cohort study on first and second singleton births in Norway

OBJECTIVE

To explore if newborns in the second pregnancy following a previous caesarean delivery (CD) have higher risk of perinatal mortality or cerebral palsy than newborns in pregnancies following a previous vaginal delivery (VD).

DESIGN

Cohort study with information from the Medical Birth Registry of Norway and the Cerebral Palsy Registry of Norway.

SETTING

Births in Norway.

PARTICIPANTS

294 598 women with their first and second singleton delivery during 1996-2015.

MAIN OUTCOME MEASURES

Stillbirth, perinatal mortality, neonatal mortality and cerebral palsy.

RESULTS

Among 294 598 included women, 42 962 (15%) had a CD in their first pregnancy while 251 636 (85%) had a VD. Compared with the second delivery of mothers with a previous VD, the adjusted OR (adjOR), for stillbirth in the second pregnancy following a previous CD was 1.45, 95% CI 1.22 to 1.73; for perinatal death the adjOR was 1.42 (1.22 to 1.73) and for neonatal death 1.13 (0.86 to 1.49). Among children who survived the neonatal period, the adjOR for cerebral palsy was 1.27 (0.99 to 1.64). Secondary outcomes, including small for gestational age, preterm and very preterm birth, uterine rupture and placental complications (eg, postpartum haemorrhage and pre-eclampsia) were more frequent in the subsequent pregnancy following a previous CD compared with a previous VD, in particular for uterine rupture adjOR 86.7 (48.2 to 156.1). Adjustment for potential confounders attenuated the ORs somewhat, but the excess risk in the second pregnancy persisted for all outcomes.

CONCLUSION

A previous CD was in this study associated with increased risk for stillbirth and perinatal death compared with a previous VD. Although less robust, we also found that a previous CD was associated with a slightly increased risk of cerebral palsy among children surviving the neonatal period. The aetiology behind these associations needs further investigation.

School Age Neurological and Cognitive Outcomes of Fetal Growth Retardation or Small for Gestational Age Birth Weight

Children who were growth restricted in utero (FGR) and are born small for gestational age (SGA) may experience poorer long term neurological and cognitive outcomes. Those also born preterm may have particular difficulties. The objective of this paper was to review the literature on school age neurocognitive outcome for term and preterm children that was published in the last 15 years. Considering term born children first, there is evidence that these children are at higher risk for Cerebral Palsy (CP) than those born appropriate for gestational age (AGA); information on neuromotor function in the absence of CP is somewhat contradictory. With regards to cognitive outcome, the most common finding was that being born SGA and/or FGR at term does not impact negatively on general intellectual functioning, commonly assessed by IQ scores. There was some indication that they may experience particular problems with attention. With regards to children born preterm, the risk of CP appears not to be increased compared to those preterms born AGA. For preterm children who do not develop CP, motor outcome is more affected by post-natal and post-neonatal brain growth than intrauterine growth. In contrast to term born children, preterm SGA and/or FGR children are at increased risk of cognitive and behavioral difficulties, and in common with term born children, are at higher risk than their AGA counterparts of difficulties with attentional control. In conclusion, preterm born SGA and/or FGR children are at higher risk of neurodevelopmental problems in the school years. It is important to continue to follow up children into the school age years because these difficulties may take time to emerge, and may be more visible in the more demanding school environment.

Combined Analysis of Interleukin-10 Gene Polymorphisms and Protein Expression in Children With Cerebral Palsy

Background

Interleukin-10 (IL-10) is an important anti-inflammatory and immunosuppressive cytokine, and it has indispensable functions in both the onset and development of inflammatory disorders. The association between persistent inflammation and the development of cerebral palsy (CP) has attracted much attention.

Objective

The purpose of this study was to investigate whether IL-10 gene polymorphisms and plasma protein expression are associated with CP and to analyze the role of IL-10 in CP.

Methods

A total of 282 CP patients and 197 healthy controls were genotyped for IL-10 polymorphisms (rs1554286, rs1518111, rs3024490, rs1800871, and rs1800896). Among them, 95 CP patients and 93 healthy controls were selected for plasma IL-10 measurement.

Results

The differences in the rs3024490 (p = 0.033) and rs1800871 (p = 0.033) allele frequencies of IL-10 were determined between CP patients and controls. The frequencies of allele and genotype between CP patients with spastic tetraplegia and normal controls of IL-10 polymorphisms showed significant differences for rs1554286, rs151811, rs3024490, rs1800871, and rs1800896 (p_allele = 0.015, 0.009, 0.006, 0.003, and 0.006, p_genotype = 0.039, 0.018, 0.027, 0.012, and 0.03, respectively). The plasma IL-10 protein level in CP patients was higher than normal controls (9.13 ± 0.77 vs. 6.73 ± 0.63 pg/ml, p = 0.017). IL-10 polymorphisms and protein association analysis showed that the TT genotype had higher plasma IL-10 protein levels compared to the GG + GT genotype at rs3024490 (11.14 ± 7.27 vs. 7.44 ± 6.95 pg/ml, p = 0.045, respectively) in CP cases.

Conclusion

These findings provide an important contribution toward explaining the pleiotropic role of IL-10 in the complex etiology of CP.

Neonatal hypoxia of the second twin after vaginal delivery of the first twin: what matters?. J Matern Fetal Neonatal Med 2018. [PMID: 29527962 DOI: 10.1080/14767058.2018.1451510]

Objective: Optimal management of twin deliveries is controversial. We aimed to assess potential risk factors correlated to the development of hypoxia in the second twin after vaginal delivery of the first twin. Study design: This is a retrospective observational study including diamniotic twin pregnancies delivering at our Institution at 35 weeks of gestational age or more, weighing ≥1800 g. Hypoxia was defined as at least one of the following: Apgar score <5 at 10 minute, neonatal resuscitation for >10 minutes, neonatal acidosis (pH ≤7 and/or BE ≥12 mmol/L). Results: A number of 275 diamniotic twin pregnancies met the inclusion criteria and were divided within the following groups: (1) second twin not developing neonatal hypoxia (n = 265); and (2) second twin developing neonatal hypoxia (n = 10). The rate of second twins with neonatal hypoxia during the study period was 3.6% (10/275). Abnormal cardiotocography during the intertwin delivery interval, defined as ACOG category III, was significantly correlated to second twin hypoxia. Of interest, there was no significant difference in the intertwin delivery interval between the study groups. In addition, breech presentation of the second twin did not show to be a risk factor for neonatal hypoxia. None of the second twins developing neonatal hypoxia was reported to have encephalopathy (follow up of at least 24 months). At multivariate analysis, only abnormal cardiotocography was an independent risk factor for second twin hypoxia (OR 17.8, 95% CI 4.1-77.2). Conclusions: In our study, neonatal hypoxia was significantly correlated to abnormal cardiotocography, while intertwin delivery interval was not correlated to the development of this adverse neonatal outcome.

Completeness and correctness of cerebral palsy diagnoses in two health registers: implications for estimating prevalence

AIM

To assess completeness and correctness of cerebral palsy (CP) diagnoses in the Cerebral Palsy Register of Norway (CPRN) and the Norwegian Patient Register (NPR), and to estimate CP prevalence.

METHOD

Among 747 883 Norwegian residents born from 1996 to 2007, 2231 had a diagnosis of CP in the NPR while 1441 were registered in the CPRN. Children registered in the CPRN were considered to have a valid CP diagnosis. For those with a diagnosis of CP only in the NPR, two paediatricians reviewed the hospital records. The prevalence rate of CP with 95% confidence intervals (CI) was calculated on the basis of the combined data sets.

RESULTS

One thousand three hundred and ninety-eight children were registered with a diagnosis of CP in both registers, 43 children were only registered in the CPRN, and 824 only in the NPR. The review of hospital records revealed that 464 (59.5%) had CP. Thus, the NPR was 98% complete, and for 86% the diagnosis was correct. The completeness of the CPRN was 76%, while the diagnosis was considered correct for all children (100%). The resulting prevalence of CP was 2.5 (95% CI 2.4-2.7) per 1000.

INTERPRETATION

To gain accurate estimates of prevalence rates of CP, it is essential to combine data sources and to validate register data.

Decreasing prevalence in cerebral palsy: a multi-site European population-based study, 1980 to 2003

AIM

To monitor the trends in prevalence of cerebral palsy (CP) by birthweight in Europe, 1980 to 2003.

METHOD

Data were collated from 20 population-based registers contributing to the Surveillance of Cerebral Palsy in Europe database. Trend analyses were conducted in four birthweight groups: <1000g (extremely low birthweight [ELBW]); 1000 to 1499g (very low birthweight [VLBW]); 1500 to 2499g (moderately low birthweight [MLBW]); and >2499g (normal birthweight [NBW]).

RESULTS

The overall prevalence of CP decreased from 1.90 to 1.77 per 1000 live births, p<0.001, with a mean annual fall of 0.7% (95% confidence interval [CI] -0.3% to -1.0%). Prevalence in NBW children showed a non-significant trend from 1.17 to 0.89 per 1000 live births (p=0.22). Prevalence in MLBW children decreased from 8.5 to 6.2 per 1000 live births (p<0.001), but not linearly. Prevalence in VLBW children also declined from 70.9 to 35.9 per 1000 live births (p<0.001) with a mean annual fall of 3.4% (95% CI -2.4% to -4.3%). Prevalence in ELBW children remained stable, at a mean rate of 42.4 per 1000 live births.

INTERPRETATION

The decline in prevalence of CP in children of VLBW continues, and confirms that previously reported. For the first time, there is also a significant decline among those of MLBW, resulting in a significant overall decrease in the prevalence of CP.

Genes determining the severity of cerebral palsy: the role of single nucleotide polymorphisms on the amount and structure of apolipoprotein E

AIM

Apolipoprotein E (apoE) influences repair and other processes in the brain, and the apoE4 variant is a risk factor for Alzheimer's disease and for prolonged recovery following traumatic brain injury. We previously reported that specific single nucleotide polymorphisms in the APOE or TOMM40 genes affecting the structure and production of apoE were associated with epilepsy, more impaired hand function and gastrostomy tube feeding in children with cerebral palsy (CP). This study explored how various combinations of the same polymorphisms may affect these clinical manifestations.

METHODS

Successful DNA analyses of APOE and TOMM40 were carried out on 227 children. The CP Register of Norway provided details of gross and fine motor function, epilepsy and gastrostomy tube feeding. Possible associations between these clinical manifestations and various combinations of the APOEε2, ε3 or ε4 alleles and of the rs59007384 polymorphism in the TOMM40 gene were explored.

RESULTS

Epilepsy, impaired fine motor function and gastrostomy tube feeding were less common in children carrying the combination of rs59007384 GG and APOEε2 or ε3 than in children with other combinations.

CONCLUSION

Our findings suggest that specific combinations of genes influence the structure and production of apoE differently and affect the clinical manifestations of CP.

Child apolipoprotein E gene variants and risk of cerebral palsy: estimation from case-parent triads

OBJECTIVE

To use case-parent triad data to investigate if cerebral palsy (CP) is associated with variants of the APOE gene, the rs59007384 SNP of the TOMM40 gene or combined haplotypes of the two genes.

STUDY DESIGN

DNA was analyzed in buccal swabs from 235 children with CP, their parents and a sibling. The relative risks (RR) with 95% confidence intervals (CI) that the children would have a distribution of APOE genotypes, rs59007384 variants or combined haplotypes deviating from Mendelian inheritance were estimated.

RESULTS

Children with CP were more likely than expected to carry the APOEε3 allele (RR 7.5; CI: 0.99-53.7 for heterozygotes and 10.3; CI: 1.4-79.6 for homozygotes), and to have the haplotype of APOEε3 and rs59007384 G (RR 2.4; CI: 1-5.7 for heterozygotes, RR 3.7; CI: 1.4-9.5 for homozygotes) whereas the distribution was as expected for rs59007384 alone. In the subgroup analyses the findings were confined to children born preterm. Among siblings the distribution of these genes was as expected according to Mendelian inheritance.

CONCLUSION

We speculate that children with APOEε2/APOEε4 alleles are more likely to die following cerebral injury in utero, resulting in a higher than expected proportion of children with CP carrying the APOEε3 allele.

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.

Cerebral palsy in Al-Quseir City, Egypt: prevalence, subtypes, and risk factors

Cerebral palsy (CP) is the most frequent cause of motor handicap. The present door-to-door survey was conducted in Al-Quseir City, Egypt, to investigate the epidemiology of CP. All inhabitants were screened by three neurologists. Medical and neurological examinations were performed for all residents and suspected cases of CP were confirmed by meticulous neurological assessment, brain magnetic resonance imaging, electroencephalography, and testing with the Stanford-Binet Intelligence Scale. Forty-six of 12,788 children aged ≤18 years were found to have CP, yielding a childhood prevalence of 3.6 (95% confidence interval 1.48-2.59) per 1,000 live births. Five adults (aged 19-40 years) among 13,056 inhabitants had CP, giving an adult prevalence of 0.4 (95% confidence interval 0.04-0.72) per 1,000. The risk factors for CP identified in this study were premature birth, low birth weight, neonatal jaundice, neonatal seizures, and recurrent abortion in mothers of children with CP.

Mediators of the association between pre-eclampsia and cerebral palsy: population based cohort study

OBJECTIVE

To test the hypothesis that pre-eclampsia is a risk factor for cerebral palsy mediated through preterm birth and being born small for gestational age.

DESIGN

Population based cohort study.

SETTING

Clinical data from the Norwegian Cerebral Palsy Registry were linked with perinatal data prospectively recorded by the Medical Birth Registry of Norway.

PARTICIPANTS

All singleton babies who survived the neonatal period during 1996-2006 (849 children with cerebral palsy and 616,658 control children).

MAIN OUTCOME MEASURES

Cerebral palsy and cerebral palsy subtypes.

RESULTS

Children exposed to pre-eclampsia had an excess risk of cerebral palsy (unadjusted odds ratio 2.5, 95% confidence interval 2.0 to 3.2) compared with unexposed children. Among children born at term (≥ 37 weeks), exposure to pre-eclampsia was not associated with an excess risk of cerebral palsy in babies not born small for gestational age (1.2, 0.7 to 2.0), whereas children exposed to pre-eclampsia and born small for gestational age had a significantly increased risk of cerebral palsy (3.2, 1.5 to 6.7). Non-small for gestational age babies born very preterm (<32 weeks) and exposed to pre-eclampsia had a reduced risk of cerebral palsy compared with unexposed children born at the same gestational age (0.5, 0.3 to 0.8), although the risk was not statistically significantly reduced among children exposed to pre-eclampsia and born small for gestational age (0.7, 0.4 to 1.3). Exposure to pre-eclampsia was not associated with a specific cerebral palsy subtype.

CONCLUSIONS

Exposure to pre-eclampsia was associated with an increased risk of cerebral palsy, and this association was mediated through the children being born preterm or small for gestational age, or both. Among children born at term, pre-eclampsia was a risk factor for cerebral palsy only when the children were small for gestational age.

Apolipoprotein E polymorphisms and severity of cerebral palsy: a cross-sectional study in 255 children in Norway

AIM

The aim of this study was to examine whether the presence of the apolipoprotein E (ApoE) allele APOEε4 is associated with less severe manifestations of cerebral palsy (CP), consistent with the suggested beneficial effect of this allele on neurodevelopment in children.

METHOD

ApoE genotyping was performed on buccal epithelial cells from 255 children (141 males 114 females; mean age 12y, SD 2y 3mo, range 9-17y) recorded in the Cerebral Palsy Register of Norway. The main outcome measure of CP severity was the Gross Motor Function Classification System (GMFCS). Secondary outcome measures were fine motor function, epilepsy, and the need for gastrostomy tube feeding (GTF).

RESULTS

There was no association between the APOEε4 genotype and GMFCS levels (odds ratio [OR] 1.15; 95% confidence interval [CI] 0.66-1.99). However, the APOEε4 genotype was more often present among children with epilepsy (OR 2.2; 95% CI 1.1-4.2) and/or receiving GTF (OR 2.7; 95% CI 1.1-6.6). Among children with unilateral CP, the presence of APOEε4 was associated with more severe fine motor impairment (OR 2.6; 95% CI 1.3-6.9).

INTERPRETATION

Our main hypothesis that APOEε4 would have a protective effect on neurodevelopment was not supported. Instead, subgroup analyses suggested an adverse effect of the APOEε4 genotype on the developing brain after injury.

Cerebral palsy and neonatal death in term singletons born small for gestational age

BACKGROUND AND OBJECTIVES

To investigate the probable timing of events leading to cerebral palsy (CP) in singletons born small for gestational age (SGA) at term, taking neonatal death into consideration.

METHODS

In this registry-based cohort study, data on 400 488 singletons born during 1996-2003 were abstracted from the Medical Birth and the CP registries of Norway. Among 36 604 SGA children (birth weight <10th percentile), 104 died in the neonatal period and 69 developed CP. Apgar scores at 5 minutes, risk factors, MRI findings, and CP subtypes were used to assess the timing of events leading to CP or neonatal death.

RESULTS

Intrapartum origin of CP was considered in 5 SGA children (7%; 95% confidence interval: 3-16) in comparison with 31 of 263 (12%; 95% confidence interval: 8-16) non-SGA children (P = .28). The proportions of children who died in the neonatal period after a probable intrapartum event did not differ between the groups when children with congenital malformations were excluded. Probable antenatal events leading to CP and neonatal death were more common among SGA than non-SGA children (P < .001).

CONCLUSIONS

In ~90% of children born SGA the event leading to CP is of probable antenatal origin. The low proportion of SGA children with CP after a probable intrapartum event was not outweighed by a higher neonatal mortality rate when congenital malformations were excluded. The higher risk of CP among SGA than among non-SGA children is probably due to a higher prevalence of antenatal risk factors.