Non-infectious risk factors for different types of cerebral palsy in term-born babies: a population-based, case-control study

Comparison of outcomes following surgical intervention and inpatient rehabilitation stays in children with cerebral palsy

INTRODUCTION

Literature is limited on functional outcomes in children with cerebral palsy (CP) following surgical procedures and a subsequent inpatient rehabilitation unit (IRU) stay.

OBJECTIVE

To compare functional outcomes and length of stay (LOS) in children with CP following a surgical procedure and IRU stay based on the surgical procedure performed, pattern of involvement, etiology, and Gross Motor Function Classification System (GMFCS) level.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care pediatrics.

PARTICIPANTS

Pediatric patients with CP who underwent one of three surgical procedures followed by an IRU stay.

INTERVENTIONS

Selective dorsal rhizotomy (SDR), single-event multilevel orthopedic surgery (SEMLS), or intrathecal baclofen (ITB) pump implantation and subsequent IRU stay.

MAIN OUTCOME MEASURES

IRU LOS, Functional Independence Measure for Children (WeeFIM) total score, sub-scores, and efficiency.

RESULTS

Children undergoing SDR had a longer LOS (p ≤ .015). Children with spastic diplegia, GMFCS level II, and prematurity-based CP had higher WeeFIM efficiency scores (p ≤ .046, ≤.021, and .034 respectively). Greater changes in WeeFIM™ scores were associated with spastic diplegia, SDR, GMFCS level II, longer LOS, and higher admission scores (p ≤ .045).

CONCLUSIONS

Although statistically and functionally significant improvements in children with CP following surgical interventions and an IRU stay were seen, those with higher WeeFIM change scores tended to have spastic diplegia, to have undergone SDR, GMFCS level II, longer LOS, and higher admission scores.

Maternal body mass index and cerebral palsy in children: A systematic review and dose-response meta-analysis

BACKGROUND

Accumulating studies indicate that maternal obesity is associated with the risk of cerebral palsy (CP); however, their conclusions have been inconsistent.

OBJECTIVES

To quantitatively estimate the association between maternal body mass index (BMI) and CP in offspring.

DATA SOURCES

PubMed, Embase and Web of Science.

STUDY SELECTION AND DATA EXTRACTION

Articles published up to 18 September 2022 were searched that reported the correlation between maternal BMI and CP in children. Two reviewers independently extracted data and critically assessed articles.

SYNTHESIS

Pooled relative risks (RR) and 95% confidence intervals (CI) were estimated by the random-effects model. Subgroup analysis and meta-regression were performed to explore sources of heterogeneity.

RESULTS

In total, 11 articles (8,407,668 participants) were identified for inclusion in our meta-analysis. For maternal underweight, no significant association was found with CP risk (RR 1.11, 95% CI 0.90, 1.38). The risk of CP was increased by 25% (RR 1.25, 95% CI 1.06, 1.47), 38% (RR 1.38, 95% CI 1.18, 1.61) and 127% (RR 2.27, 95% CI 1.82, 2.83) for maternal overweight, obesity and obesity grade 3, respectively. In addition, we observed a positive linear dose-response relationship, with the pooled risk of cerebral palsy in offspring increasing by 3% with each unit increase in maternal BMI.

CONCLUSION

This meta-analysis indicates that the risk of CP in offspring grew with maternal overweight or obesity grades increasing, and was positively correlated with maternal BMI.

Prevalence of cerebral palsy and factors associated with cerebral palsy subtype: A population-based study in Belgium

AIM

To report on the prevalence, neuroimaging patterns, and function of children with cerebral palsy (CP) in Belgium for birth years 2007-2012, and identify distinctive risk indicators and differences in outcome between CP subtypes.

METHODS

Antenatal and perinatal/neonatal factors, motor and speech function, associated impairments, and neuroimaging patterns were extracted from the Belgian Cerebral Palsy Register. Prevalence was estimated per 1000 (overall, ante/perinatal, spastic, dyskinetic CP) or 10,000 (post-neonatal, ataxic CP) live births. Multinomial logistic regression analyses were performed to ascertain the effects of antenatal/perinatal/neonatal factors and neuroimaging patterns on the likelihood of dyskinetic or ataxic CP relative to spastic CP, and test the likelihood of the occurrence of impaired motor and speech function and associated impairments in dyskinetic or ataxic CP relative to spastic CP.

RESULTS

In total, 1127 children with CP were identified in Belgium. The birth prevalence of overall CP was 1.48 per 1000 live births. The likelihood of dyskinetic CP increases if the child was born to a mother aged ≥35 years, mechanically ventilated, and had predominant grey matter injury, while an increased likelihood of ataxic CP is associated with ≥2 previous deliveries. Children with dyskinetic and ataxic CP are more likely to function with impairments in motor, speech, and intellectual abilities.

CONCLUSION

Distinctive risk indicators and differences in outcome between CP subtypes were identified. These factors can be incorporated into clinical practice to facilitate early, accurate, and reliable classification of CP subtype, and may lead to individually tailored neonatal care and other (early) intervention options.

Physical Therapy Interventions in Children With Cerebral Palsy: A Systematic Review

Cerebral palsy is a group of disorders affecting individuals already from birth. It enormously impacts an individual's physical and emotional life and can bring many challenges to the individual, caregivers, and families. Therefore, it is crucial to investigate interventions that could improve various symptoms in children with cerebral palsy. Our systematic review intends to assess the effect of different exercise and physical therapy interventions in children with cerebral palsy. We used three databases for our article search: PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), and PubMed Central (PMC). The combined number of papers found in all databases was 65,412. We then applied our inclusion and exclusion criteria, filters, key terms, and Medical Subheadings (MeSH). After applying our quality assessment tools, we included nine papers in our systematic review. The studies included in our review used various interventions to assess for improvement in symptoms in individuals with cerebral palsy. Interventions included stretching and resistance exercises, horse riding, biking, core stability exercises, slackline training, a home exercise program using an online tool, sit-to-stand exercise program, and functional training. Many studies have shown that interventions improved symptoms like balance, coordination, gait, and cardiovascular endurance in cerebral palsy. This review suggests that some of the included interventions have great potential to improve the symptoms of cerebral palsy and, therefore, can be a great addition to existing training and rehabilitation programs. Given that studies included a relatively small number of participants and were conducted over a short time, more research with a more significant number of participants over a longer time is necessary.

Lights and shadows on the use of metformin in pregnancy: from the preconception phase to breastfeeding and beyond

During pregnancy, the complex hormonal changes lead to a progressive decrease of insulin sensitivity that can drive the onset of gestational diabetes (GDM) or worsen an already-known condition of insulin resistance like type 2 diabetes, polycystic ovarian syndrome (PCOS), and obesity, with complications for the mother and the fetus. Metformin during pregnancy is proving to be safe in a growing number of studies, although it freely crosses the placenta, leading to a fetal level similar to maternal concentration. The aim of this literature review is to analyze the main available evidence on the use of metformin during, throughout, and beyond pregnancy, including fertilization, lactation, and medium-term effects on offspring. Analyzed studies support the safety and efficacy of metformin during pregnancy. In pregnant women with GDM and type 2 diabetes, metformin improves obstetric and perinatal outcomes. There is no evidence that it prevents GDM in women with pregestational insulin resistance or improves lipid profile and risk of GDM in pregnant women with PCOS or obesity. Metformin could have a role in reducing the risk of preeclampsia in pregnant women with severe obesity, the risk of late miscarriages and preterm delivery in women with PCOS, and the risk of ovarian hyperstimulation syndrome, increasing the clinical pregnancy rate in women with PCOS undergoing in vitro fertilization (IVF/FIVET). Offspring of mothers with GDM exposed to metformin have no significant differences in body composition compared with insulin treatment, while it appears to be protective for metabolic and cardiovascular risk.

Maternal Obesity and Gut Microbiota Are Associated with Fetal Brain Development

Obesity in pregnancy induces metabolic syndrome, low-grade inflammation, altered endocrine factors, placental function, and the maternal gut microbiome. All these factors impact fetal growth and development, including brain development. The lipid metabolic transporters of the maternal-fetal-placental unit are dysregulated in obesity. Consequently, the transport of essential long-chain PUFAs for fetal brain development is disturbed. The mother’s gut microbiota is vital in maintaining postnatal energy homeostasis and maternal-fetal immune competence. Obesity during pregnancy changes the gut microbiota, affecting fetal brain development. Obesity in pregnancy can induce placental and intrauterine inflammation and thus influence the neurodevelopmental outcomes of the offspring. Several epidemiological studies observed an association between maternal obesity and adverse neurodevelopment. This review discusses the effects of maternal obesity and gut microbiota on fetal neurodevelopment outcomes. In addition, the possible mechanisms of the impacts of obesity and gut microbiota on fetal brain development are discussed.

Does motor deficit in children with cerebral palsy correlate with diffusion tensor metrics abnormalities in thalamocortical pathways?

Background

Cerebral palsy (CP) is a group of motor-impairment signs secondary to many disorders that interfere with early brain development and are usually related to white matter injury in children. Most studies are focused on the study of motor tracts, mainly the corticospinal tract (CST). Diffusion tensor imaging (DTI) is a reliable imaging modality providing an appropriate method of detection of white matter microstructure abnormalities. The purpose of this study is to investigate the relationship between DTI observed motor CST injury, sensory pathways (thalamic radiations) injury, and motor functions.

Results

This study shows significant involvement (reduction in DTI fiber count) of the superior thalamic radiation (in severe cases) with atrophy of the anterior thalamic radiations (ATR) or posterior thalamic radiations (PTR) in most cases with a significant reduction in fractional anisotropy (FA) and elevation in mean diffusivity (MD) values. In addition, the degree of motor affection shows a significant negative correlation with FA and a significant positive correlation with MD values. Diffusion tensor imaging shows a significant reduction in FA within the examined tracts between CP and control at the Rt CST, Lt CST, Rt corticothalamic radiation (CTR), and Lt CTR with significant cutoff values of ≤ 0.449, ≤ 0.472, ≤ 0.432, and ≤ 0.44, respectively.

Conclusions

This study demonstrates disruption of thalamocortical and corticospinal tracts in CP patients, which reflects that both sensory and motor tract affection have a valuable role in the pathophysiology of motor dysfunction in CP patients.

Analysis of Selected Risk Factors Depending on the Type of Cerebral Palsy

Background: Cerebral palsy (CP) is not a defined, separate disease classification, but a set of etiologically diverse symptoms that change with the child's age. According to the up-to-date definition, CP is a group of permanent but not unchanging disorders of movement and/or posture and motor function, which are due to a nonprogressive interference, lesion, or abnormality of the developing/immature brain. CP is one of the most frequent causes of motor disability in children. The aim of the present study was to analyze whether selected risk factors may vary depending on particular types of CP. Methods: 181 children with CP (aged 4-17 years), hospitalized at the Department of Pediatrics and Developmental Age Neurology in Katowice in the years 2008-2016 were retrospectively analyzed in the present study. The assumed risk factors of CP were divided into two groups: 1-pre-conception and prenatal (mother's age, family history of epilepsy, burdened obstetric history, mother's systemic diseases, pregnancy order, multiple pregnancy, duration of pregnancy, bleedings from the genital tract during gestation, arterial hypertension during pregnancy, infections during pregnancy, preterm contractions, maintained pregnancy, premature rupture of membranes, abruptio placentae, and others), 2-perinatal and postnatal (mode of delivery, birth weight, Apgar score at the first and fifth minute, neonatal convulsions, respiratory failure, infections in neonatal and infant period, and intraventricular bleeding). The division into particular CP types was based on Ingram's classification. Results: The following risk factors were the most frequent in the total group: respiratory failure, infections, intraventricular bleeding, and prematurity. Among the analyzed preconception and prenatal factors, the duration of pregnancy and preterm contractions during pregnancy significantly differentiated the subgroups of patients depending on the type of CP. The prevalence of almost all analyzed perinatal, neonatal, and infant-related risk factors (i.e., birth weight, Apgar score at the first and fifth minute, neonatal convulsions, respiratory failure, infections in neonatal and infant period, and intraventricular bleeding) significantly differed between CP types, apart from the mode of delivery. However, in multivariate regression, only intraventricular bleeding was an independent predictor for tetraplegic CP type when compared to joined extrapyramidal and ataxic types (OR = 2.801, p = 0.028). Conclusions: As CP is a syndrome of multifactorial etiology, the identification of CP risk factors entails the need for careful observation and comprehensive care of children in the risk group. The presence of certain risk factors may be a prognostic indicator for particular types of CP. The knowledge about the association between the risk factor(s) and the CP type could be a very useful tool for pediatricians looking after the child at risk of developmental disorders.

Intrauterine growth restriction followed by oxygen support uniquely interferes with genetic regulators of myelination

Intrauterine growth restriction (IUGR) and oxygen exposure in isolation and combination adversely affect the developing brain, putting infants at risk for neurodevelopmental disability including cerebral palsy. Rodent models of IUGR and postnatal hyperoxia have demonstrated oligodendroglial injury with subsequent white matter injury (WMI) and motor dysfunction. Here we investigate transcriptomic dysregulation in IUGR with and without hyperoxia exposure to account for the abnormal brain structure and function previously documented. We performed RNA sequencing and analysis using a mouse model of IUGR and found that IUGR, hyperoxia, and the combination of IUGR with hyperoxia (IUGR/hyperoxia) produced distinct changes in gene expression. IUGR in isolation demonstrated the fewest differentially expressed genes compared to control. In contrast, we detected several gene alterations in IUGR/hyperoxia; genes involved in myelination were strikingly downregulated. We also identified changes to specific regulators including TCF7L2, BDNF, SOX2, and DGCR8, through Ingenuity Pathway Analysis, that may contribute to impaired myelination in IUGR/hyperoxia. Our findings show that IUGR with hyperoxia induces unique transcriptional changes in the developing brain. These indicate mechanisms for increased risk for WMI in IUGR infants exposed to oxygen and suggest potential therapeutic targets to improve motor outcomes.Significance StatementThis study demonstrates that perinatal exposures of IUGR and/or postnatal hyperoxia result in distinct transcriptomic changes in the developing brain. In particular, we found that genes involved in normal developmental myelination, myelin maintenance, and remyelination were most dysregulated when IUGR was combined with hyperoxia. Understanding how multiple risk factors lead to WMI is the first step in developing future therapeutic interventions. Additionally, because oxygen exposure is often unavoidable after birth, an understanding of gene perturbations in this setting will increase our awareness of the need for tight control of oxygen use to minimize future motor disability.

Intrauterine cytomegalovirus infection: a possible risk for cerebral palsy and related to its clinical features, neuroimaging findings: a retrospective study

Background

Abundant clinical evidences indicate that the increased risk of cerebral palsy (CP) may be associated with the intrauterine exposure to maternal infection. Cytomegalovirus (CMV) is a common cause of CP. However, little is known about the relationship between the intrauterine exposure of the fetus to CMV infection and CP. This study aims to explore the relationships between intrauterine CMV infection and clinical symptoms, classification, intelligence development and brain neuroimaging findings in children with CP.

Methods

In this study, 147 children with CP in recent 6 years were retrospectively analyzed (average age: 14.76 ± 3.07months; sex (M/F): 103/44). 148 children had CMV IgG and IgM positive sera identified by TORCH examination were selected as the control group (average age: 15.10 ± 3.21months; sex (M/F): 102/46), which also undergo the examination of CMV-DNA in urine. The age and sex of children in the control group were matched with those in the CP group. CMV-DNA in urine was detected by CMV fluorescence quantitative PCR, and t-test was performed to analyze the number of copies. For the CP group, standardized rehabilitation treatment was performed and the function of gross motor was evaluated by GMFM scale before and after treatment. The Gesell developmental scale (GDS) was used to assess the level of intellectual development. The classification of CP was conducted and the results of magnetic resonance imaging were analyzed. Finally, the correlations between the copy number of CMV-DNA and the clinical characteristics of children with CP were evaluated by the method of Pearson and Spearman correlation analysis.

Results

The level of CMV infection was negatively correlated with the developmental quotient (DQ) of children with CP. Negative association was found between the level of CMV infection and the level of the gross motor development. The level of CMV infection was positively related with the occurrence probability of spastic quadriplegia. However, no associations were found between the abnormalities of brain tissue and the number of CMV copies. Moreover, CMV infection might add the difficulty of the rehabilitation treatment.

Conclusions

CMV infection is a risk factor for the occurrence of CP in children. Pregnancy examination should be strengthened. Early detection and control of CMV infection may contribute to the rehabilitation of children with CP and reduce the disability and social burden.

Associations between antenatal and perinatal risk factors and cerebral palsy: a Swedish cohort study

OBJECTIVES

To investigate known and suggested risk factors associated with cerebral palsy in a Swedish birth cohort, stratified by gestational age.

SETTING

Information on all births between 1995 and 2014 in Skåne, the southernmost region in Sweden, was extracted from the national birth register.

PARTICIPANTS

The cohort comprised a total of 215 217 children. Information on confirmed cerebral palsy and subtype was collected from the national quality register for cerebral palsy (Cerebral Palsy Follow-up Surveillance Programme).

PRIMARY AND SECONDARY OUTCOME MEASURES

We calculated the prevalence of risk factors suggested to be associated with cerebral palsy and used logistic regression models to investigate the associations between potential risk factors and cerebral palsy. All analyses were stratified by gestational age; term (≥37 weeks), moderately or late preterm (32-36 weeks) and very preterm (<32 weeks).

RESULTS

In all, 381 (0.2 %) children were assigned a cerebral palsy diagnosis. Among term children, maternal preobesity/obesity, small for gestational age, malformations, induction, elective and emergency caesarian section, Apgar <7 at 5 min and admission to neonatal care were significantly associated with cerebral palsy (all p values<0.05). Among children born moderately or late preterm, small for gestational age, malformations, elective and emergency caesarian section and admission to neonatal care were all associated with cerebral palsy (all p values <0.05), whereas among children born very preterm no factors were significantly associated with the outcome (all p values>0.05).

CONCLUSION

Our results support and strengthen previous findings on factors associated with cerebral palsy. The complete lack of significant associations among children born very preterm probably depends on to the small number of children with cerebral palsy in this group.

Cerebral Palsy: Current Opinions on Definition, Epidemiology, Risk Factors, Classification and Treatment Options

Cerebral palsy (CP) is one of the most frequent causes of motor disability in children. According to the up-to-date definition, CP is a group of permanent disorders of the development of movement and posture, causing activity limitations that are attributed to non-progressive disturbances that occurred in the developing foetal or infant brain. The CP definition has evolved over time; the problem is aetiologically and clinically very heterogeneous. According to European data, the average frequency of CP is 2.08 per 1000 live births, but in the group of children born with a body weight below 1500 g, the frequency is 70 times higher when compared with the group of children with a body weight over 2500 g at birth. The risk factors for CP can be divided into pre-conception, prenatal, perinatal and postnatal ones. CP commonly co-exists with epilepsy, in particular drug-resistant epilepsy, but also with mental retardation, visual and hearing impairment, as well as feeding and behavioral disorders. The degree of motor problem varies from mild to very severe making the child totally dependent on caregivers. Cerebral palsy is divided into forms depending on the type of motor disorders which dominate the clinical presentation; the traditional classifications by Ingram and Hagberg have now been replaced by the Surveillance of Cerebral Palsy in Europe classification which divides CP into spastic, dyskinetic and ataxic forms. Although cerebral palsy is a clinical diagnosis, modern diagnostic imaging provides information that allows the division of the results of magnetic resonance imaging in children with cerebral palsy into five groups according to the magnetic resonance imaging classification system. Just as the clinical presentation and the factors predisposing for CP are very diverse, treatment is also a very complex problem. Modern treatment of spasticity includes both botulinum toxin therapies and surgical techniques, eg, rhizotomy. The authors present current views on definitions, risk factors, diagnostics and treatment of CP as well as comorbid problems, eg, drug-resistant epilepsy.

Impact of parental over- and underweight on the health of offspring

Parental excess weight and especially pregestational maternal obesity and excessive weight gain during pregnancy have been related to an increased risk of metabolic (obesity, type 2 diabetes, cardiovascular disease, metabolic syndrome) and nonmetabolic (cancer, osteoporosis, asthma, neurologic alterations) diseases in the offspring, probably mediated by epigenetic mechanisms of fetal programming. Maternal underweight is less common in developed societies, but the discrepancy between a poor nutritional environment in utero and a normal or excessive postnatal food supply with rapid growth catch-up appears to be the main candidate mechanism of the development of chronic diseases during the offspring's adulthood. The role of the postnatal environment in both scenarios (parental overweight or underweight) also seems to influence the offspring's health. Lifestyle interventions before and during pregnancy in both parents, but especially in the mother, as well as in children after birth, are advisable to counteract the many undesirable chronic conditions described.

Maternal obesity and risk of cerebral palsy in children: a systematic review and meta-analysis

AIM

Several studies have examined the links between maternal obesity and the risk of cerebral palsy (CP) in children, with inconsistent results. The aim of our study was to investigate whether maternal obesity is associated with increased risk of CP in offspring by using meta-analysis.

METHOD

PubMed and Web of Science were searched until August 2017. Observational studies relevant to the maternal obesity and risk of CP in children were extracted and compiled. Meta-analyses were performed for different obesity levels and pooled odds ratios (ORs) and 95% confidence intervals (CIs) were reported.

RESULTS

A total of five cohort studies involving 12 324 cases and 7 919 288 participants were included in our meta-analysis. The pooled crude and adjusted ORs (95% CIs) were 1.65 (1.38-1.98) and 1.51 (1.24-1.84) respectively. Additionally, the pooled OR (95% CI) for CP in offspring in relation to maternal obesity class I (body mass index [BMI] 30.0-34.9), class II (BMI 35.0-39.9), and class III (BMI≥40.0) compared with normal weight during prepregnancy or pregnancy was 1.31 (1.15-1.50), 1.65 (1.34-2.02), and 2.37 (1.91-2.94) respectively.

INTERPRETATION

This meta-analysis demonstrated that increasing grades of maternal obesity are associated with a higher risk of CP in offspring.

WHAT THIS PAPER ADDS

Meta-analysis demonstrates a significant positive association between maternal obesity and the risk of cerebral palsy (CP) in children. Subgroup analysis indicates that higher grades of maternal obesity are associated with increasing risk of CP.

Intrauterine Growth Restriction and Hyperoxia as a Cause of White Matter Injury

Intrauterine growth restriction (IUGR) is estimated to occur in 5% of pregnancies, with placental insufficiency being the most common cause in developed countries. While it is known that white matter injury occurs in premature infants, the extent of IUGR on white matter injury is less defined in term infants. We used a novel murine model that utilizes a thromboxane A2 (TXA2) analog (U46619), a potent vasoconstrictor, to induce maternal hypertension and mimic human placental insufficiency-induced IUGR to study the white matter. We also investigated the role of hyperoxia as an additional risk factor for white matter injury, as IUGR infants are at increased risk of respiratory comorbidities leading to increased oxygen exposure. We found that TXA2 analog-induced IUGR results in white matter injury as demonstrated by altered myelin structure and changes in the oligodendroglial cell/oligodendrocyte population. In addition, our study demonstrates that hyperoxia exposure independently results in white matter perturbation. To our knowledge, this is the first study to report single and combined effects of IUGR with hyperoxia impacting the white matter and motor function. These results draw attention to the need for close monitoring of motor development in IUGR babies following hospital discharge as well as highlighting the importance of limiting, as clinically feasible, the degree of oxygen overexposure to potentially improve motor outcomes in this population of infants.

Association between maternal overweight or obesity and cerebral palsy in children: A meta-analysis

CONTEXT

There is no consensus regarding the association between maternal obesity or overweight and cerebral palsy (CP) in children.

OBJECTIVES

To investigate whether maternal obesity or overweight is associated with CP and identify the factors that explain the differences in the study results.

DATA SOURCES

We conducted a meta-analysis of studies published in English with titles or abstracts that discussed the relationships between maternal obesity or overweight and CP before August 23, 2017, using Ovid Medline, EMBASE and Web of Science.

STUDY SELECTION

Of 2699 initially identified studies, 8 studies that addressed the association between maternal obesity and CP met our final inclusion criteria.

DATA EXTRACTION

Information from the individual studies was abstracted using standardized forms by 2 independent observers who were blinded to the authors' names and journal titles.

DATA SYNTHESIS

According to a random effects model, maternal overweight was significantly associated with CP in offspring [RR = 1.29 (95% CI, 1.04-1.60), heterogeneity (I2 = 45.5%, P = 0.103)]; maternal obesity was significantly associated with CP in offspring [RR = 1.45 (95% CI, 1.25-1.69), heterogeneity (I2 = 24.1%, P = 0.253)]; and maternal obesity III was significantly associated with CP in offspring [RR = 2.25 (95% CI, 1.82-2.79), heterogeneity (I2 = 0%, P = 0.589)]. However, maternal underweight was not significantly associated with CP in offspring [RR = 1.11 (95% CI, 0.88-1.38), low heterogeneity (I2 = 0%, P = 0.435)]. Factors that explained the differences in the meta-analysis results included study design, study location, and whether individual studies adjusted for potential confounders.

CONCLUSION

This study suggests that maternal obesity and overweight increase the risk of CP in offspring. Further studies are required to confirm these results and determine the influence of variables across studies.

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.

Are Extremely Low Gestational Age Newborns Born to Obese Women at Increased Risk of Cerebral Palsy at 2 Years?

The authors hypothesized that the risk of cerebral palsy at 2 years in children born extremely preterm to overweight and obese women is increased relative to the risk among children born to neither overweight nor obese women. In a multicenter prospective cohort study, the authors created multinomial logistic regression models of the risk of diparetic, quadriparetic, and hemiparetic cerebral palsy that included the prepregnancy body mass index of mothers of 1014 children born extremely preterm, cerebral palsy diagnoses of children at 2 years, as well as information about potential confounders. Overweight and obese women were not at increased risk of giving birth to a child who had cerebral palsy. The risk ratios associated with overweight varied between 1.1 for quadriparesis (95% CI = 0.5, 2.1) to 2.0 for hemiparesis (95% CI = 0.4, 9.8). The risk ratios associated with obesity varied between 0.7 for diparesis (95% CI = 0.2, 2.5) to 2.5 for hemiparesis (95% CI = 0.4, 13).

SGA as a Risk Factor for Cerebral Palsy in Moderate to Late Preterm Infants: a System Review and Meta-analysis

Small for gestational age (SGA) is an established risk factor for cerebral palsy (CP) in term infants. However, there is conflicting data on the association between SGA and CP in moderate to late preterm infants. The aim of the article was to explore the relationship between SGA and CP in the moderate to late preterm infants and its strength by meta-analysis. We performed a system search in OVID (EMBASE and MEDLINE) and WANFANG from inception to May 2016. The study-specific risk estimates were pooled using the random-effect model. A total of seven studies were included in the meta-analysis, consisting of three cohort and four case-control studies. A statistically significant association was found between SGA and CP in moderate to late premature infants (OR: 2.34; 95% CI: 1.43-3.82). The association were higher in the several subgroups: 34-36 week gestational age (OR: 3.47; 95% CI: 1.29-9.31), SGA < 2SDs (OR: 3.48; 95% CI: 1.86-6.49), and malformation included in CP (OR: 3.00; 95% CI: 1.71-5.26). In moderate to late premature infants, SGA is a convenient and reliable predictor for CP. More studies are needed to explore the underlying mechanisms between SGA and CP association.

Maternal obesity and neurodevelopmental and psychiatric disorders in offspring

There is a growing body of evidence from both human epidemiologic and animal studies that prenatal and lactational exposure to maternal obesity and high-fat diet are associated with neurodevelopmental and psychiatric disorders in offspring. These disorders include cognitive impairment, autism spectrum disorders, attention deficit hyperactivity disorder, cerebral palsy, anxiety and depression, schizophrenia, and eating disorders. This review synthesizes human and animal data linking maternal obesity and high-fat diet consumption to abnormal fetal brain development and neurodevelopmental and psychiatric morbidity in offspring. In addition, it highlights key mechanisms by which maternal obesity and maternal diet might impact fetal and offspring neurodevelopment, including neuroinflammation; increased oxidative stress, dysregulated insulin, glucose, and leptin signaling; dysregulated serotonergic and dopaminergic signaling; and perturbations in synaptic plasticity. Finally, the review summarizes available evidence regarding investigational therapeutic approaches to mitigate the harmful effects of maternal obesity on fetal and offspring neurodevelopment. © 2016 John Wiley & Sons, Ltd.

Maternal Prepregnancy BMI and Risk of Cerebral Palsy in Offspring

OBJECTIVES

To investigate the association between maternal pre-pregnancy BMI and risk of cerebral palsy (CP) in offspring.

METHODS

The study population consisted of 188 788 children in the Mothers and Babies in Norway and Denmark CP study, using data from 2 population-based, prospective birth cohorts: the Norwegian Mother and Child Cohort Study and the Danish National Birth Cohort. Prepregnancy BMI was classified as underweight (BMI <18.5), lower normal weight (BMI 18.5-22.9), upper normal weight (BMI 23.0-24.9), overweight (BMI 25.0-29.9), and obese (BMI ≥30). CP diagnoses were obtained from the national CP registries. Associations between maternal prepregnancy BMI and CP in offspring were investigated by using log-binomial regression models.

RESULTS

The 2 cohorts had 390 eligible cases of CP (2.1 per 1000 live-born children). Compared with mothers in the lower normal weight group, mothers in the upper normal group had a 40% excess risk of having a child with CP (relative risk [RR], 1.35; 95% confidence interval [CI], 1.03-1.78). Excess risk was 60% (RR, 1.56; 95% CI, 1.21-2.01) for overweight mothers and 60% (RR, 1.55; 95% CI 1.11-2.18) for obese mothers. The risk of CP increased ∼4% for each unit increase in BMI (RR, 1.04; 95% CI, 1.02-1.06). Estimates changed little with adjustment for mother's occupational status, age, and smoking habits.

CONCLUSIONS

Higher prepregnancy maternal BMI was associated with increased risk of CP in offspring.

Motor vehicle crashes during pregnancy and cerebral palsy during infancy: a longitudinal cohort analysis

OBJECTIVES

To assess the incidence of cerebral palsy among children born to mothers who had their pregnancy complicated by a motor vehicle crash.

DESIGN

Retrospective longitudinal cohort analysis of children born from 1 April 2002 to 31 March 2012 in Ontario, Canada.

PARTICIPANTS

Cases defined as pregnancies complicated by a motor vehicle crash and controls as remaining pregnancies with no crash.

MAIN OUTCOME

Subsequent diagnosis of cerebral palsy by age 3 years.

RESULTS

A total of 1 325 660 newborns were analysed, of whom 7933 were involved in a motor vehicle crash during pregnancy. A total of 2328 were subsequently diagnosed with cerebral palsy, equal to an absolute risk of 1.8 per 1000 newborns. For the entire cohort, motor vehicle crashes correlated with a 29% increased risk of subsequent cerebral palsy that was not statistically significant (95% CI -16 to +110, p=0.274). The increased risk was only significant for those with preterm birth who showed an 89% increased risk of subsequent cerebral palsy associated with a motor vehicle crash (95% CI +7 to +266, p=0.037). No significant increase was apparent for those with a term delivery (95% CI -62 to +79, p=0.510). A propensity score-matched analysis of preterm births (n=4384) yielded a 138% increased relative risk of cerebral palsy associated with a motor vehicle crash (95% CI +27 to +349, p=0.007), equal to an absolute increase of about 10.9 additional cases per 1000 newborns (18.2 vs 7.3, p=0.010).

CONCLUSIONS

Motor vehicle crashes during pregnancy may be associated with an increased risk of cerebral palsy among the subgroup of cases with preterm birth. The increase highlights a specific role for traffic safety advice in prenatal care.

Assessing the fetal effects of maternal obesity via transcriptomic analysis of cord blood: a prospective case-control study

OBJECTIVE

To analyse fetal gene expression at term using umbilical cord blood, in order to provide insights into the effects of maternal obesity on human development.

DESIGN

Prospective case-control study.

SETTING

Academic tertiary care centre.

POPULATION

Eight obese (body mass index ≥30 kg/m(2)) and eight lean (body mass index <25 kg/m(2)) pregnant women undergoing prelabour caesarean delivery at term.

METHODS

Women were matched for gestational age and fetal sex. Cord blood RNA was extracted and hybridised to gene expression arrays. Differentially regulated genes were identified using paired t-tests and the Benjamini-Hochberg correction. Functional analyses were performed using Ingenuity Pathway Analysis, BioGPS and Gene Set Enrichment Analysis with a fetal-specific annotation. Z-scores ≥2.0 or P-values <0.01 were considered significant.

MAIN OUTCOME MEASURE

Functions of differentially regulated genes in fetuses of obese women.

RESULTS

A total of 701 differentially regulated genes were identified, producing an expression profile implicating neurodegeneration, decreased survival of sensory neurons, and decreased neurogenesis in the fetuses of obese women. Upstream regulators related to inflammatory signalling were significantly activated; those related to insulin receptor signalling, lipid homeostasis, regulation of axonal guidance, and cellular response to oxidative stress were significantly inhibited. Of 26 tissue-specific genes that were differentially regulated in fetuses of obese women, six mapped to the fetal brain.

CONCLUSION

Maternal obesity affects fetal gene expression at term, implicating dysregulated brain development, inflammatory and immune signalling, glucose and lipid homeostasis, and oxidative stress. This may have implications for postnatal neurodevelopment and metabolism.

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.

Effects of Maternal Obesity on Fetal Programming: Molecular Approaches

Maternal obesity has become a worldwide epidemic. Obesity and a high-fat diet have been shown to have deleterious effects on fetal programming, predisposing offspring to adverse cardiometabolic and neurodevelopmental outcomes. Although large epidemiological studies have shown an association between maternal obesity and adverse outcomes for offspring, the underlying mechanisms remain unclear. Molecular approaches have played a key role in elucidating the mechanistic underpinnings of fetal malprogramming in the setting of maternal obesity. These approaches include, among others, characterization of epigenetic modifications, microRNA expression, the gut microbiome, the transcriptome, and evaluation of specific mRNA expression via quantitative reverse transcription polmerase chain reaction (RT-qPCR) in fetuses and offspring of obese females. This work will review the data from animal models and human fluids/cells regarding the effects of maternal obesity on fetal and offspring neurodevelopment and cardiometabolic outcomes, with a particular focus on molecular approaches.

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.

Fetal growth restriction and risk of cerebral palsy in singletons born after at least 35 weeks' gestation

OBJECTIVE

The objective of the study was to improve the understanding of etiological paths to cerebral palsy (CP) that include fetal growth restriction by examining factors associated with growth restriction that modify CP risk.

STUDY DESIGN

In a total population of singletons born at or after 35 weeks, there were 493 children with CP and 508 matched controls for whom appropriateness of fetal growth could be estimated. Fetal growth was considered markedly restricted if birthweight was more than 2 SD below optimal for gender, gestation, maternal height, and parity. We examined maternal blood pressure in pregnancy, smoking, birth asphyxia, and major birth defects recognized by age 6 years as potential modifiers of CP risk in growth-restricted births.

RESULTS

More than 80% of term and late preterm markedly growth-restricted singletons were born following a normotensive pregnancy and were at statistically significantly increased risk of CP (odds ratio, 4.81; 95% confidence interval, 2.7-8.5), whereas growth-restricted births following a hypertensive pregnancy were not. Neither a clinical diagnosis of birth asphyxia nor potentially asphyxiating birth events occurred more frequently among growth-restricted than among appropriately grown infants with CP. Major birth defects, particularly cerebral defects, occurred in an increasing proportion of CP with increasing growth deficit. The factor most predictive of CP in growth-restricted singletons was a major birth defect, present in 53% of markedly growth-restricted neonates with later CP. Defects observed in CP were similar whether growth restricted or not, except for an excess of isolated congenital microcephaly in those born growth restricted. The highest observed CP risk was in infants with both growth restriction and a major birth defect (8.9% of total CP in this gestational age group, 0.4% of controls: odds ratio, 30.9; 95% confidence interval, 7.0-136).

CONCLUSION

The risk of CP was increased in antenatally growth-restricted singletons born at or near term to normotensive mothers. In growth-restricted singletons, a major birth defect was the dominant predictor, associated with a 30-fold increase in odds of CP. Identification of birth defects in the growth-restricted fetus or neonate may provide significant prognostic information.

Maternal diagnosis of obesity and risk of cerebral palsy in the child

OBJECTIVE

To examine the association between maternal hospital diagnoses of obesity and risk of cerebral palsy (CP) in the child.

STUDY DESIGN

For all California hospital births from 1991-2001, we linked infant and maternal hospitalization discharge abstracts to California Department of Developmental Services records of children receiving services for CP. We identified maternal hospital discharge diagnoses of obesity (International Classification of Diseases, 9th edition 646.1, 278.00, or 278.01) and morbid obesity (International Classification of Diseases, 9th edition 278.01), and performed logistic regression to explore the relationship between maternal obesity diagnoses and CP.

RESULTS

Among 6.2 million births, 67 200 (1.1%) mothers were diagnosed with obesity, and 7878 (0.1%) with morbid obesity; 8798 (0.14%) children had CP. A maternal diagnosis of obesity (relative risk [RR] 1.30, 95% CI 1.09-1.55) or morbid obesity (RR 2.70, 95% CI 1.89-3.86) was associated with increased risk of CP. In multivariable analysis adjusting for maternal race, age, education, prenatal care, insurance status, and infant sex, both obesity (OR 1.27, 95% CI 1.06-1.52) and morbid obesity (OR 2.56, 95% CI 1.79-3.66) remained independently associated with CP. On stratified analyses, the association of obesity (RR 1.72, 95% CI 1.25-2.35) or morbid obesity (RR 3.79, 95% CI 2.35-6.10) with CP was only significant among women who were hospitalized prior to the birth admission. Adjusting for potential comorbidities and complications of obesity did not eliminate this association.

CONCLUSIONS

Maternal obesity may confer an increased risk of CP in some cases. Further studies are needed to confirm this finding.

Cerebral palsy and perinatal infection in children born at term

OBJECTIVE

To investigate the link between infection-related risk factors for cerebral palsy subtypes in children born at term.

METHODS

A case-control study was performed in a population-based series of children with cerebral palsy born at term (n=309) matched with a control group (n=618). The cases were divided into cerebral palsy subtypes: spastic hemiplegia, spastic diplegia, spastic tetraplegia, and dyskinetic cerebral palsy. All forms of spastic cerebral palsy were also analyzed together. All records were examined for maternal and neonatal signs of infection. Univariate and adjusted analyses were performed.

RESULTS

Infection-related risk factors were shown to be independent risk factors for spastic cerebral palsy in the adjusted analyses. This was especially pronounced in the subgroup with spastic hemiplegia in which bacterial growth in urine during pregnancy (n=11 [7.5%], odds ratio [OR] 4.7, 95% confidence interval [CI] 1.5-15.2), any infectious disease during pregnancy (n=57 [39.0%], OR 2.9, 95% CI 1.7-4.8), severe infection during pregnancy (n=12 [8.2%], OR 15.4, 95% CI 3.0-78.1), antibiotic therapy once during pregnancy (n=33 [22.6%], OR 6.3, 95% CI 3.0-15.2) as well as several times during pregnancy (n=9 [6.2%], OR 15.6, 95% CI 1.8-134.2) constituted strong independent risk factors. However, only neonatal infection (n=11 [9.1%], OR 14.7, 95% CI 1.7-126.5) was independently significantly associated with an increased risk of spastic diplegia and tetraplegia.

CONCLUSIONS

Infection-related factors are strong independent risk factors for the subgroup with spastic hemiplegia in children with cerebral palsy born at term. The finding is less pronounced in the subgroups with spastic diplegia or tetraplegia.

LEVEL OF EVIDENCE

II.