A comparison of cohorts of children with cerebral palsy from a population register and hospital admission data: A data linkage study.

BACKGROUND: Administrative health data, such as hospital admission data, are often used in research to identify children/young people with cerebral palsy (CP). OBJECTIVES: To compare sociodemographic, clinical details and mortality of children/young people identified as having CP in either a CP population registry or hospital admission data. METHODS: We identified two cohorts of children/young people (birth years 2001-2010, age at study end or death 2 months to 19 years 6 months) with a diagnosis of CP from either (i) the New South Wales (NSW)/Australian Capital Territory (ACT) CP Register or (ii) NSW hospital admission data (2001-2020). Using record linkage, these data sources were linked to each other and NSW Death, Perinatal, and Disability datasets. We determined the sensitivity and positive predictive value (PPV) of CP diagnosis in hospital admission data compared with the NSW/ACT CP Register (gold standard). We then compared the sociodemographic and clinical characteristics and mortality of the two cohorts available through record linkage using standardised mean difference (SMD). RESULTS: There were 1598 children/young people with CP in the NSW/ACT CP Register and 732-2439 children/young people with CP in hospital admission data, depending on the case definition used. The sensitivity of hospital admission data for diagnosis of CP ranged from 0.40-0.74 and PPV 0.47-0.73. Compared with children/young people with CP identified in the NSW/ACT CP Register, a greater proportion of those identified in hospital admission data (one or more admissions with G80 case definition) were older, lived in major cities, had comorbidities including epilepsy, gastrostomy use, intellectual disability and autism, and died during the study period (SMD > 0.1). CONCLUSIONS: Sociodemographic and clinical characteristics differ between cohorts of children/young people with CP identified using a CP register or hospital admission data. Those identified in hospital admission data have higher rates of comorbidities and death, suggesting some may have progressive conditions and not CP. These differences should be considered when planning and interpreting research using various data sources.

Neonatal magnesium sulphate for neuroprotection: A systematic review and meta-analysis.

AIM: To review the evidence of the effects of neonatal magnesium sulphate for neuroprotection in perinatal asphyxia and hypoxic-ischaemic encephalopathy (HIE). METHOD: This was a systematic review of randomized controlled trials (RCTs) (with meta-analysis) and non-RCTs assessing magnesium sulphate for treating perinatal asphyxia and HIE at 35 weeks or more gestation (primary outcomes: neonatal death and death or long-term major neurodevelopmental disability). RESULTS: Twenty-five RCTs (2099 infants) and four non-RCTs (871 infants) were included, 23 in low- and middle-income countries (LMICs). In RCTs, reductions in neonatal death with magnesium sulphate versus placebo or no treatment (risk ratio [RR] = 0.68; 95% confidence interval [CI] = 0.53-0.86; 13 RCTs), and magnesium sulphate with melatonin versus melatonin alone (RR = 0.74; 95% CI = 0.58-0.95; one RCT) were observed. No difference in neonatal death was seen for magnesium sulphate with therapeutic hypothermia versus therapeutic hypothermia alone (RR = 0.66, 95% CI = 0.34-1.26; three RCTs), or magnesium sulphate versus phenobarbital (RR = 3.00; 95% CI = 0.86-10.46; one RCT). No reduction in death or long-term neurodevelopmental disability (RR = 0.52; 95% CI = 0.14-1.89; one RCT) but reductions in several short-term adverse outcomes were observed with magnesium sulphate. Evidence was low- to very-low certainty because of risk of bias and imprecision. INTERPRETATION: Given the uncertainty of the current evidence, further robust neonatal magnesium sulphate research is justified. This may include high-quality studies to determine stand-alone effects in LMICs and effects with and after therapeutic hypothermia in high-income countries.

Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus.

BACKGROUND: Magnesium sulphate is a common therapy in perinatal care. Its benefits when given to women at risk of preterm birth for fetal neuroprotection (prevention of cerebral palsy for children) were shown in a 2009 Cochrane review. Internationally, use of magnesium sulphate for preterm cerebral palsy prevention is now recommended practice. As new randomised controlled trials (RCTs) and longer-term follow-up of prior RCTs have since been conducted, this review updates the previously published version. OBJECTIVES: To assess the effectiveness and safety of magnesium sulphate as a fetal neuroprotective agent when given to women considered to be at risk of preterm birth. SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) on 17 March 2023, as well as reference lists of retrieved studies. SELECTION CRITERIA: We included RCTs and cluster-RCTs of women at risk of preterm birth that assessed prenatal magnesium sulphate for fetal neuroprotection compared with placebo or no treatment. All methods of administration (intravenous, intramuscular, and oral) were eligible. We did not include studies where magnesium sulphate was used with the primary aim of preterm labour tocolysis, or the prevention and/or treatment of eclampsia. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed RCTs for inclusion, extracted data, and assessed risk of bias and trustworthiness. Dichotomous data were presented as summary risk ratios (RR) with 95% confidence intervals (CI), and continuous data were presented as mean differences with 95% CI. We assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS: We included six RCTs (5917 women and their 6759 fetuses alive at randomisation). All RCTs were conducted in high-income countries. The RCTs compared magnesium sulphate with placebo in women at risk of preterm birth at less than 34 weeks' gestation; however, treatment regimens and inclusion/exclusion criteria varied. Though the RCTs were at an overall low risk of bias, the certainty of evidence ranged from high to very low, due to concerns regarding study limitations, imprecision, and inconsistency. Primary outcomes for infants/children: Up to two years' corrected age, magnesium sulphate compared with placebo reduced cerebral palsy (RR 0.71, 95% CI 0.57 to 0.89; 6 RCTs, 6107 children; number needed to treat for additional beneficial outcome (NNTB) 60, 95% CI 41 to 158) and death or cerebral palsy (RR 0.87, 95% CI 0.77 to 0.98; 6 RCTs, 6481 children; NNTB 56, 95% CI 32 to 363) (both high-certainty evidence). Magnesium sulphate probably resulted in little to no difference in death (fetal, neonatal, or later) (RR 0.96, 95% CI 0.82 to 1.13; 6 RCTs, 6759 children); major neurodevelopmental disability (RR 1.09, 95% CI 0.83 to 1.44; 1 RCT, 987 children); or death or major neurodevelopmental disability (RR 0.95, 95% CI 0.85 to 1.07; 3 RCTs, 4279 children) (all moderate-certainty evidence). At early school age, magnesium sulphate may have resulted in little to no difference in death (fetal, neonatal, or later) (RR 0.82, 95% CI 0.66 to 1.02; 2 RCTs, 1758 children); cerebral palsy (RR 0.99, 95% CI 0.69 to 1.41; 2 RCTs, 1038 children); death or cerebral palsy (RR 0.90, 95% CI 0.67 to 1.20; 1 RCT, 503 children); and death or major neurodevelopmental disability (RR 0.81, 95% CI 0.59 to 1.12; 1 RCT, 503 children) (all low-certainty evidence). Magnesium sulphate may also have resulted in little to no difference in major neurodevelopmental disability, but the evidence is very uncertain (average RR 0.92, 95% CI 0.53 to 1.62; 2 RCTs, 940 children; very low-certainty evidence). Secondary outcomes for infants/children: Magnesium sulphate probably reduced severe intraventricular haemorrhage (grade 3 or 4) (RR 0.76, 95% CI 0.60 to 0.98; 5 RCTs, 5885 infants; NNTB 92, 95% CI 55 to 1102; moderate-certainty evidence) and may have resulted in little to no difference in chronic lung disease/bronchopulmonary dysplasia (average RR 0.92, 95% CI 0.77 to 1.10; 5 RCTs, 6689 infants; low-certainty evidence). Primary outcomes for women: Magnesium sulphate may have resulted in little or no difference in severe maternal outcomes potentially related to treatment (death, cardiac arrest, respiratory arrest) (RR 0.32, 95% CI 0.01 to 7.92; 4 RCTs, 5300 women; low-certainty evidence). However, magnesium sulphate probably increased maternal adverse effects severe enough to stop treatment (average RR 3.21, 95% CI 1.88 to 5.48; 3 RCTs, 4736 women; moderate-certainty evidence). Secondary outcomes for women: Magnesium sulphate probably resulted in little to no difference in caesarean section (RR 0.96, 95% CI 0.91 to 1.02; 5 RCTs, 5861 women) and postpartum haemorrhage (RR 0.94, 95% CI 0.80 to 1.09; 2 RCTs, 2495 women) (both moderate-certainty evidence). Breastfeeding at hospital discharge and women's views of treatment were not reported. AUTHORS' CONCLUSIONS: The currently available evidence indicates that magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus, compared with placebo, reduces cerebral palsy, and death or cerebral palsy, in children up to two years' corrected age, and probably reduces severe intraventricular haemorrhage for infants. Magnesium sulphate may result in little to no difference in outcomes in children at school age. While magnesium sulphate may result in little to no difference in severe maternal outcomes (death, cardiac arrest, respiratory arrest), it probably increases maternal adverse effects severe enough to stop treatment. Further research is needed on the longer-term benefits and harms for children, into adolescence and adulthood. Additional studies to determine variation in effects by characteristics of women treated and magnesium sulphate regimens used, along with the generalisability of findings to low- and middle-income countries, should be considered.

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.

Cerebral palsy registers around the world: A survey.

AIM: To provide a description of cerebral palsy (CP) registers globally, identify which aim to report on CP epidemiology, and report similarities and differences across topics of importance for the sustainability and collaboration between registers. METHOD: Representatives of all known CP registers globally (n = 57) were invited to participate. The online survey included 68 questions across aims, methodologies, output/impact, and stakeholder involvement. Responses were analysed using descriptive statistics. RESULTS: Forty-five registers participated, including three register networks. Twenty were newly established or under development, including 12 in low- and middle-income countries (LMICs). An epidemiological aim was reported by 91% of registers. Funding is received by 85% of registers, most often from not-for-profit organizations. CP definitions are comparable across registers. While the minimum data set of a register network is used by most registers, only 25% of identified items are collected by all three register networks. Ninety per cent of registers measure research activities/output, and 64% measure research impact. People with lived experience are involved in 62% of registers. INTERPRETATION: There has been a recent surge in CP registers globally, particularly in LMICs, which will improve understanding of CP epidemiology. Ongoing efforts to address identified methodological differences are essential to validate comparison of results and support register collaboration.

Declining trends in birth prevalence and severity of singletons with cerebral palsy of prenatal or perinatal origin in Australia: A population-based observational study.

AIM: To investigate temporal trends in birth prevalence, disability severity, and motor type for singletons with prenatal or perinatally acquired cerebral palsy (CP). METHOD: Numerator data, number of children with CP born a singleton between 1995 and 2014, confirmed at 5 years of age, were drawn from three state registers with population-level ascertainment. Birth prevalence estimates and 95% confidence intervals (CI) were calculated per 1000 singleton live births for the three states combined, overall, by gestational age group, by dichotomized disability severity, and spastic laterality. Poisson regression models were used to analyse trends. Using data from all eight registers, trends in the proportional distribution of CP subtypes overall and stratified by gestational age were examined. RESULTS: Birth prevalence of CP declined from 1.8 (95% CI 1.6-2.0) in 1995 to 1996 to 1.2 (95% CI 1.1-1.4) in 2013 to 2014 (average 5% per 2-year epoch, p < 0.001). Declines in birth prevalence were observed across all gestational age groups with the largest decline in children born at <28 weeks (average 8% per epoch, p < 0.001). Prevalence of moderate-severe disability declined for children born at <28 and ≥37 weeks (average 11% and 7% per epoch respectively, p < 0.001). The proportions of bilateral spastic CP declined (p < 0.001) at <28 weeks (p = 0.014) and ≥37 weeks (p < 0.001). The proportion of children with dyskinesia increased (28-31 weeks: p = 0.021, 32-36 weeks: p = 0.001, and ≥37 weeks: p < 0.001). INTERPRETATION: Birth prevalence of CP and moderate-severe disability (<28 and ≥37 weeks) declined in Australian singletons between 1995 and 2014, reflecting changes in prenatal and perinatal care over time. WHAT THIS PAPER ADDS: Declines in birth prevalence of prenatal or perinatally acquired cerebral palsy were observed for singletons born in Australia between 1995 and 2014. These declines were evident across all gestational age groups. Declines in birth prevalence of moderate-severe disability were observed for children born at <28 weeks and ≥37 weeks.

Non-attendance at outpatient clinic appointments by children with cerebral palsy.

AIM: To determine factors that influence non-attendance at outpatient clinics by children with cerebral palsy (CP). METHOD: This was a retrospective cohort study of 1395 children with CP (59.6% male; born 2005 to 2017) identified from the New South Wales (NSW)/Australian Capital Territory CP Register, who had scheduled appointments at outpatient clinics at two NSW tertiary paediatric hospitals between 2012 and 2019. Associations between sociodemographic, clinical, and process-of-care factors and non-attendance were examined using multivariate logistic regression with generalized estimating equations. RESULTS: A total of 5773 (12%) of 50 121 scheduled outpatient days were not attended. Non-attendance increased over time (average increase 5.6% per year, 95% confidence interval [CI]: 3.7-7.3). Older children aged 5 to 9 years (adjusted odds ratio [aOR] 1.11; 95% CI: 1.02-1.22) and 10 to 14 years (aOR 1.17; 95% CI: 1.03-1.34), socioeconomic disadvantage (aOR 1.29; 95% CI: 1.11-1.50), previous non-attendance (aOR 1.38; 95% CI: 1.23-1.53), and recent rescheduled or cancelled appointments (aOR 1.08; 95% CI: 1.01-1.16) were associated with increased likelihood of non-attendance. INTERPRETATION: One in eight outpatient appointments for children with CP were not attended. Non-attendance was associated with increasing age, socioeconomic disadvantage, previous non-attendance, and recent rescheduled or cancelled appointments. Identifying specific barriers and interventions to improve access to outpatient services for these groups is needed. WHAT THIS PAPER ADDS: Twelve per cent of scheduled appointments for children with cerebral palsy are not attended. Proportions of appointments not attended has increased over the last decade. Increasing age and socioeconomic disadvantage increase the likelihood of non-attendance. Previous non-attendance and recent cancelled or rescheduled appointments increase the likelihood of further non-attendance.

Global prevalence of cerebral palsy: A systematic analysis.

AIM: To determine trends and current estimates in regional and global prevalence of cerebral palsy (CP). METHOD: A systematic analysis of data from participating CP registers/surveillance systems and population-based prevalence studies (from birth year 1995) was performed. Quality and risk of bias were assessed for both data sources. Analyses were conducted for pre-/perinatal, postnatal, neonatal, and overall CP. For each region, trends were statistically classified as increasing, decreasing, heterogeneous, or no change, and most recent prevalence estimates with 95% confidence intervals (CI) were calculated. Meta-analyses were conducted to determine current birth prevalence estimates (from birth year 2010). RESULTS: Forty-one regions from 27 countries across five continents were represented. Pre-/perinatal birth prevalence declined significantly across Europe and Australia (11 out of 14 regions), with no change in postneonatal CP. From the limited but increasing data available from regions in low- and middle-income countries (LMICs), birth prevalence for pre-/perinatal CP was as high as 3.4 per 1000 (95% CI 3.0-3.9) live births. Following meta-analyses, birth prevalence for pre-/perinatal CP in regions from high-income countries (HICs) was 1.5 per 1000 (95% CI 1.4-1.6) live births, and 1.6 per 1000 (95% CI 1.5-1.7) live births when postneonatal CP was included. INTERPRETATION: The birth prevalence estimate of CP in HICs declined to 1.6 per 1000 live births. Data available from LMICs indicated markedly higher birth prevalence. WHAT THIS PAPER ADDS: • Birth prevalence of pre-/perinatal cerebral palsy (CP) in high-income countries (HICs) is decreasing. • Current overall CP birth prevalence for HICs is 1.6 per 1000 live births. • Trends in low- and middle-income countries (LMICs) cannot currently be measured. • Current birth prevalence in LMICs is markedly higher than in HICs. • Active surveillance of CP helps to assess the impact of medical advancements and social/economic development. • Population-based data on prevalence and trends of CP are critical to inform policy.

Determinants of Hospital-Based Health Service Utilization in Cerebral Palsy: a Systematic Review.

OBJECTIVE: To systematically review and synthesize evidence of determinants associated with hospital-based health service utilization among individuals with cerebral palsy (CP). DATA SOURCES: Electronic databases MEDLINE, Embase, APA Psycinfo were searched from January 2000 to April 2020. STUDY SELECTION: Observational studies were included that described people with CP, reported quantitative measures of hospital-based health service utilization (inpatient, outpatient, emergency department), and based in high-income countries. We excluded studies that included only subsets of people with CP, or those that only reported therapy service utilization. DATA EXTRACTION: After initial screen, 2 reviewers reviewed full texts for inclusion and performed data extraction and risk of bias assessment using the Newcastle-Ottawa scale. Determinants of health service utilization were identified and categorized using the Andersen behavioral model. DATA SYNTHESIS: Seventeen studies met inclusion criteria. Study quality was high. Twenty-six determinants were reported across 8 Andersen model characteristics. Individual predisposing factors such as sex showed no difference in health service utilization; inpatient admissions decreased with increasing age during childhood and was lower in adults. Increased health service utilization was associated with "individual need" including severe gross motor disability, epilepsy, developmental/ intellectual disability and gastrostomy-use across inpatient, outpatient and emergency department settings. There was little information reported on socio-demographic and health system contextual determinants. CONCLUSIONS: CP health service utilization is associated with age, severity and comorbidities. Improved understanding of determinants of health service utilization can support health service access for people with CP.

Congenital anomalies in children with postneonatally acquired cerebral palsy: an international data linkage study.

AIM: To describe the major congenital anomalies present in children with postneonatally acquired cerebral palsy (CP), and to compare clinical outcomes and cause of postneonatally acquired CP between children with and without anomalies. METHOD: Data were linked between total population CP and congenital anomaly registers in five European and three Australian regions for children born 1991 to 2009 (n=468 children with postneonatally acquired CP; 255 males, 213 females). Data were pooled and children classified into mutually exclusive categories based on type of congenital anomaly. The proportion of children with congenital anomalies was calculated. Clinical outcomes and cause of postneonatally acquired CP were compared between children with and without anomalies. RESULTS: Major congenital anomalies were reported in 25.6% (95% confidence interval [CI] 21.7-29.9) of children with postneonatally acquired CP. Cardiac anomalies, often severe, were common and present in 14.5% of children with postneonatally acquired CP. Clinical outcomes were not more severe in children with congenital anomalies than those without anomalies. Cause of postneonatally acquired CP differed with the presence of congenital anomalies, with cerebrovascular accidents predominating in the anomaly group. Congenital anomalies were likely associated with cause of postneonatally acquired CP in 77% of children with anomalies. INTERPRETATION: In this large, international study of children with postneonatally acquired CP, congenital anomalies (particularly cardiac anomalies) were common. Future research should determine specific causal pathways to postneonatally acquired CP that include congenital anomalies to identify opportunities for prevention. WHAT THIS PAPER ADDS: One-quarter of children with postneonatally acquired cerebral palsy (CP) have a major congenital anomaly. Cardiac anomalies, often severe, are the most common anomalies. Causes of postneonatally acquired CP differ between children with and without congenital anomalies.

Cerebral palsy in twins and higher multiple births: a Europe-Australia population-based study.

AIM: To describe the birth prevalence, temporal trends, and clinical outcomes of twins, triplets, or quadruplets with cerebral palsy (CP). METHOD: This was a cross-sectional study using data for twins, triplets, and quadruplets with prenatally or perinatally acquired CP and pooled from the Surveillance of Cerebral Palsy in Europe network (born 1992-2009) and Australian Cerebral Palsy Register (born 1993-2009). Children were at least 4 years old at time of registration. Children born in regions with population ascertainment and available denominator data were included in prevalence calculations (n=1033 twins, 81 triplets, and 11 quadruplets). Clinical data from children registered in all participating registers were described, including 2163 twins (56% male), 187 triplets (59% male), and 20 quadruplets (45% male). RESULTS: The birth prevalence of CP was higher with increasing plurality (twins 6.5 per 1000 live births [95% confidence interval {CI} 6.1-6.9], triplets 17.1 [95% CI 13.6-21.2], quadruplets 50.7 [95% CI 25.6-88.9]); however, prevalence by gestational age was similar across all pluralities. Between 1992-1994 and 2007-2009, prevalence of CP among twins declined (p=0.001) but prevalence of CP among triplets did not change significantly over time (p=0.55). The distributions of Gross Motor Function Classification System, epilepsy, and impairments of intellect, vision, and hearing were similar regardless of plurality. INTERPRETATION: The data combined from two CP register networks indicated that triplets and quadruplets had increased risk of CP compared to twins. The higher prevalence of CP in triplets and quadruplets is due to their higher risk of preterm birth. Prevalence of CP among twins significantly declined in Europe and Australia. Clinical outcomes were similar for all multiple births.

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).

Cerebral palsy trends in Australia (1995-2009): a population-based observational study.

AIM: To investigate trends in birth prevalence of cerebral palsy (CP) overall and by gestational age, and examine the distribution of motor type, spastic topography, and severity using Australian CP Register data from 1995 to 2009. METHOD: Prenatal and perinatal CP data were collated from state/territory CP registers. Birth prevalence estimates per 1000 live births and per 1000 neonatal survivors (NNS) were calculated in five epochs. Data from three state registers with population-level ascertainment were used to investigate birth prevalence trends by gestational age using Poisson regression. Distribution of motor type, spastic topography, and moderate to severe disability (IQ≤50 and/or Gross Motor Function Classification System levels III-V) were evaluated within birthweight categories. RESULTS: Birth prevalence of CP varied across population-level states but within each state declined significantly over time (p<0.05). Birth prevalence per 1000 neonatal survivors declined amongst children born before 28 weeks (South Australia, Victoria p<0.001) and those born at or after 37 weeks (Victoria p<0.001, Western Australia p<0.002). Across Australia the percentage of children with bilateral spastic CP declined amongst those born less than 1000g. The percentage of children with moderate to severe disability decreased (48%-34%, p<0.001). INTERPRETATION: Birth prevalence of CP declined. Encouragingly, the percentage of children with CP whose disability was moderate to severe also decreased. WHAT THIS PAPER ADDS: Birth prevalence of cerebral palsy (CP) differed but declined across Australian states (1995-2009). Australian CP birth prevalence declined significantly amongst children born before 28 weeks and those born at or after 37 weeks. The percentage of children with moderate to severe disability decreased.

Cerebral palsy after assisted reproductive technology: a cohort study.

AIM: To calculate the birth prevalence of cerebral palsy (CP) after assisted reproductive technology (ART) and compare the clinical outcomes of children with CP after ART or natural conception. METHOD: This cohort study used linked CP and ART register data from live births in Western Australia (1994-2002). Birth prevalence was calculated and data analysed using descriptive statistics and logistic regression. It was adjusted for confounding variables and stratified by plurality and gestational age. RESULTS: In total, 211 660 live births were included; prevalence of CP was increased in children born after ART (7.2/1000 live births compared with naturally conceived births, 2.5/1000). Odds of CP were doubled for singletons; when stratified by gestational age odds were only increased in the under 32-week group. Prevalence of CP was increased in ART (9.9/1000 live births) and naturally conceived twins (8.4/1000 live births). Clinical outcomes were similar between ART and naturally conceived children. INTERPRETATION: The birth prevalence of CP is increased two-fold after ART. After stratification for gestational age and plurality, residual risk remains in singletons born very preterm. Birth prevalence of CP will be tracked over time to identify any impact of changes to clinical practice. WHAT THIS PAPER ADDS: In Western Australia, assisted reproductive technology (ART) increases birth prevalence of cerebral palsy (CP), mediated mostly by preterm and multiple births. Preterm birth alone does not account for the doubled odds of CP for ART singletons born very preterm. Clinical outcomes are similar between ART and naturally conceived children with CP.

An international survey of cerebral palsy registers and surveillance systems.

AIM: To describe cerebral palsy (CP) surveillance programmes and identify similarities and differences in governance and funding, aims and scope, definition, inclusion/exclusion criteria, ascertainment and data collection, to enhance the potential for research collaboration. METHOD: Representatives from 38 CP surveillance programmes were invited to participate in an online survey and submit their data collection forms. Descriptive statistics were used to summarize information submitted. RESULTS: Twenty-seven surveillance programmes participated (25 functioning registers, two closed owing to lack of funding). Their aims spanned five domains: resource for CP research, surveillance, aetiology/prevention, service planning, and information provision (in descending order of frequency). Published definitions guided decision making for the definition of CP and case eligibility for most programmes. Consent, case identification, and data collection methods varied widely. Ten key data items were collected by all programmes and a further seven by at least 80% of programmes. All programmes reported an interest in research collaboration. INTERPRETATION: Despite variability in methodologies, similarities exist across programmes in terms of their aims, definitions, and data collected. These findings will facilitate harmonization of data and collaborative research efforts, which are so necessary on account of the heterogeneity and relatively low prevalence of CP.

Temporal trends in cerebral palsy by impairment severity and birth gestation.

AIM: Our aim was to build on previous research indicating that rates of cerebral palsy (CP) in the Australian state of Victoria are declining, and examine whether severity of impairments is also decreasing. METHOD: Data on individuals with CP were extracted from the Victorian Cerebral Palsy Register for birth years 1983 to 2009. The yearly rates of dichotomized categories for gross motor function, motor laterality, intellectual impairment, and epilepsy per 1000 neonatal survivors and proportions in the CP cohort were tabulated and plotted by birth gestation. Linear regression modelling was used to fit prediction curves; likelihood ratio tests were used to test for differences in trends between impairment severity groups. RESULTS: Since the mid-1990s, CP rates declined in neonatal survivors of birth at all gestations. Our data suggest that the decreasing CP rates were associated with relatively greater decreases in the rates of Gross Motor Function Classification System levels III to V, bilateral CP, epilepsy, and intellectual impairment (all p<0.005). Some variation was seen between birth gestation groups. INTERPRETATION: Declines in rates of CP of all levels of severity and complexity from the mid-1990s provides 'real-world' support for the effectiveness of concurrent neuroprotective strategies and continual innovation in perinatal practices.

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.

A special supplement: findings from the Australian Cerebral Palsy Register, birth years 1993 to 2006.

AIM: To briefly outline the strengths and limitations of cerebral palsy (CP) registers, and to report on findings of the Australian Cerebral Palsy Register (ACPR) pertaining to a population cohort of children with CP. METHOD: De-identified data were extracted from the ACPR for people with CP in birth years 1993 to 2006, from South Australia, Victoria, and Western Australia. Live birth prevalence of CP was estimated and risk factors described. RESULTS: The overall birth prevalence of CP (including those whose CP was postneonatally acquired) for the 1993 to 2006 birth cohort was 2.1 per 1000 live births (95% confidence interval [CI] 2.0-2.2). Excluding cases with a known postneonatal cause, the birth prevalence for pre/perinatally acquired CP was 2.0 per 1000 live births (95% CI 1.9-2.1). A downward trend in rates of CP in those born extremely preterm was evident over at least three consecutive periods across all three regions. Most (58.6%) children were born at term (≥ 37 wks). Male sex, early gestational age, low birthweight, and multiple birth were risk factors for CP. INTERPRETATION: Overall rates of CP did not change during this period. The proportion of those with CP born extremely preterm decreased. The ACPR Group will investigate whether this pattern continues when data pertaining to the next birth cohort for all three regions becomes available.

Magnesium Sulfate Before Preterm Birth for Neuroprotection: An Updated Cochrane Systematic Review.

OBJECTIVE: To systematically review the evidence for the effectiveness and safety of magnesium sulfate as a fetal neuroprotective agent when given to individuals at risk of preterm birth. DATA SOURCES: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (through March 17, 2023), and reference lists of relevant studies. METHODS OF STUDY SELECTION: Randomized controlled trials (RCTs) assessing magnesium sulfate for fetal neuroprotection in pregnant participants at risk of imminent preterm birth were eligible. Two authors assessed RCTs for inclusion, extracted data, and evaluated risk of bias, trustworthiness, and evidence certainty (GRADE [Grading of Recommendations Assessment, Development and Evaluation]). TABULATION, INTEGRATION, AND RESULTS: We included six RCTs (5,917 pregnant participants and 6,759 fetuses at less than 34 weeks of gestation at randomization). They were conducted in high-income countries (two in the United States, two across Australia and New Zealand, and one each in Denmark and France) and commenced between 1995 and 2018. Primary outcomes: up to 2 years of corrected age, magnesium sulfate compared with placebo reduced the risk of cerebral palsy (risk ratio [RR] 0.71, 95% CI, 0.57-0.89; six RCTs, 6,107 children) and death or cerebral palsy (RR 0.87, 95% CI, 0.77-0.98; six RCTs, 6,481 children) (high-certainty evidence). Magnesium sulfate had little or no effect on death up to 2 years of corrected age (moderate-certainty evidence) or these outcomes at school age (low-certainty evidence). Although there was little or no effect on death or cardiac or respiratory arrest for pregnant individuals (low-certainty evidence), magnesium sulfate increased adverse effects severe enough to stop treatment (RR 3.21, 95% CI, 1.88-5.48; three RCTs, 4,736 participants; moderate-certainty evidence). Secondary outcome: magnesium sulfate reduced the risk of severe neonatal intraventricular hemorrhage (moderate-certainty evidence). CONCLUSION: Magnesium sulfate for preterm fetal neuroprotection reduces cerebral palsy and death or cerebral palsy for children. Further research is required on longer-term benefits and harms for children, effect variation by participant and treatment characteristics, and the generalizability of findings to low- and middle-income countries. SYSTEMATIC REVIEW REGISTRATION: The review protocol was based on a standard Cochrane Pregnancy and Childbirth template and our previous Cochrane Systematic Review (doi: 10.1002/14651858.CD004661.pub3; published before the introduction of PROSPERO).