Prevalence of Cerebral Palsy among 8-Year-Old Children in 2010 and Preliminary Evidence of Trends in Its Relationship to Low Birthweight

BACKGROUND

The public health objective for cerebral palsy (CP) in the United States is to reduce the percentage of children with CP who were born low birthweight (LBW, <2500 g) by 10% between 2006 and 2020. This study reports the prevalence of CP in a constant surveillance area for the years 2006, 2008, and 2010 and describes initial progress towards the CP public health objective.

METHODS

Data on children with CP at age 8 years were ascertained by the Autism and Developmental Disabilities Monitoring (ADDM) Network, a population-based surveillance system that monitored CP in four areas of the United States.

RESULTS

CP prevalence in 2010 was 2.9 per 1000 [95% confidence interval (CI) 2.6, 3.2], down from 3.5 (95% CI 3.2, 3.9) in the same surveillance area in 2006. Among CP cases with no documented postneonatal aetiology, 49.1% (95% CI 42.9, 55.2) were born LBW in 2010 compared with 54.3% (95% CI 48.4, 60.1) in 2006. In 2010, 28.1% (95% CI 22.9, 30.4) were born very low birthweight (VLBW, <1500 g) compared with 35.4% (95% CI 30.0, 41.2) in 2006. The relative risks for associations between CP and both LBW and VLBW also declined, though not significantly, during the study period.

CONCLUSIONS

Declines in the associations between CP and LBW categories may have contributed to declines during the study period in both the prevalence of CP and the percentage of children with CP who were born LBW or VLBW. Ongoing monitoring of these trends is warranted.

Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years--Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2012

Problem/Condition

Autism spectrum disorder (ASD).

Period Covered

2012.

Description of System

The Autism and Developmental Disabilities Monitoring (ADDM) Network is an active surveillance system that provides estimates of the prevalence and characteristics of ASD among children aged 8 years whose parents or guardians reside in 11 ADDM Network sites in the United States (Arkansas, Arizona, Colorado, Georgia, Maryland, Missouri, New Jersey, North Carolina, South Carolina, Utah, and Wisconsin). Surveillance to determine ASD case status is conducted in two phases. The first phase consists of screening and abstracting comprehensive evaluations performed by professional service providers in the community. Data sources identified for record review are categorized as either 1) education source type, including developmental evaluations to determine eligibility for special education services or 2) health care source type, including diagnostic and developmental evaluations. The second phase involves the review of all abstracted evaluations by trained clinicians to determine ASD surveillance case status. A child meets the surveillance case definition for ASD if one or more comprehensive evaluations of that child completed by a qualified professional describes behaviors that are consistent with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision diagnostic criteria for any of the following conditions: autistic disorder, pervasive developmental disorder–not otherwise specified (including atypical autism), or Asperger disorder. This report provides ASD prevalence estimates for children aged 8 years living in catchment areas of the ADDM Network sites in 2012, overall and stratified by sex, race/ethnicity, and the type of source records (education and health records versus health records only). In addition, this report describes the proportion of children with ASD with a score consistent with intellectual disability on a standardized intellectual ability test, the age at which the earliest known comprehensive evaluation was performed, the proportion of children with a previous ASD diagnosis, the specific type of ASD diagnosis, and any special education eligibility classification.

Results

For 2012, the combined estimated prevalence of ASD among the 11 ADDM Network sites was 14.6 per 1,000 (one in 68) children aged 8 years. Estimated prevalence was significantly higher among boys aged 8 years (23.6 per 1,000) than among girls aged 8 years (5.3 per 1,000). Estimated ASD prevalence was significantly higher among non-Hispanic white children aged 8 years (15.5 per 1,000) compared with non-Hispanic black children (13.2 per 1,000), and Hispanic (10.1 per 1,000) children aged 8 years. Estimated prevalence varied widely among the 11 ADDM Network sites, ranging from 8.2 per 1,000 children aged 8 years (in the area of the Maryland site where only health care records were reviewed) to 24.6 per 1,000 children aged 8 years (in New Jersey, where both education and health care records were reviewed). Estimated prevalence was higher in surveillance sites where education records and health records were reviewed compared with sites where health records only were reviewed (17.1 per 1,000 and 10.7 per 1,000 children aged 8 years, respectively; p<0.05). Among children identified with ASD by the ADDM Network, 82% had a previous ASD diagnosis or educational classification; this did not vary by sex or between non-Hispanic white and non-Hispanic black children. A lower percentage of Hispanic children (78%) had a previous ASD diagnosis or classification compared with non-Hispanic white children (82%) and with non-Hispanic black children (84%). The median age at earliest known comprehensive evaluation was 40 months, and 43% of children had received an earliest known comprehensive evaluation by age 36 months. The percentage of children with an earliest known comprehensive evaluation by age 36 months was similar for boys and girls, but was higher for non-Hispanic white children (45%) compared with non-Hispanic black children (40%) and Hispanic children (39%).

Interpretation

Overall estimated ASD prevalence was 14.6 per 1,000 children aged 8 years in the ADDM Network sites in 2012. The higher estimated prevalence among sites that reviewed both education and health records suggests the role of special education systems in providing comprehensive evaluations and services to children with developmental disabilities. Disparities by race/ethnicity in estimated ASD prevalence, particularly for Hispanic children, as well as disparities in the age of earliest comprehensive evaluation and presence of a previous ASD diagnosis or classification, suggest that access to treatment and services might be lacking or delayed for some children.

Public Health Action

The ADDM Network will continue to monitor the prevalence and characteristics of ASD among children aged 8 years living in selected sites across the United States. Recommendations from the ADDM Network include enhancing strategies to 1) lower the age of first evaluation of ASD by community providers in accordance with the Healthy People 2020 goal that children with ASD are evaluated by age 36 months and begin receiving community-based support and services by age 48 months; 2) reduce disparities by race/ethnicity in identified ASD prevalence, the age of first comprehensive evaluation, and presence of a previous ASD diagnosis or classification; and 3) assess the effect on ASD prevalence of the revised ASD diagnostic criteria published in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.

Prevalence of cerebral palsy and intellectual disability among children identified in two U.S. National Surveys, 2011-2013

PURPOSE

Cerebral palsy (CP) and intellectual disability (ID) are developmental disabilities that result in considerable functional limitations. There are few recent and nationally representative prevalence estimates of CP and ID in the United States.

METHODS

We used two U.S. nationally representative surveys, the 2011-2012 National Survey of Children's Health (NSCH) and the 2011-2013 National Health Interview Survey (NHIS), to determine the prevalence of CP and ID based on parent report among children aged 2-17 years.

RESULTS

CP prevalence was 2.6 (95% confidence interval [CI]: 2.1-3.2) per 1000 in the NSCH and 2.9 (95% CI: 2.3-3.7) in the NHIS. ID prevalence was 12.2 (95% CI: 10.7-13.9) and 12.1 (95% CI: 10.8-13.7) in NSCH and NHIS, respectively. For both conditions, the NSCH and NHIS prevalence estimates were similar to each other for nearly all sociodemographic subgroups examined.

CONCLUSIONS

Despite using different modes of data collection, the two surveys produced similar and plausible estimates of CP and ID and offer opportunities to better understand the needs and situations of children with these conditions.

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.

Birth Prevalence of Cerebral Palsy: A Population-Based Study

OBJECTIVE

Population-based data in the United States on trends in cerebral palsy (CP) birth prevalence are limited. The objective of this study was to examine trends in the birth prevalence of congenital spastic CP by birth weight, gestational age, and race/ethnicity in a heterogeneous US metropolitan area.

METHODS

Children with CP were identified by a population-based surveillance system for developmental disabilities (DDs). Children with CP were included if they were born in metropolitan Atlanta, Georgia, from 1985 to 2002, resided there at age 8 years, and did not have a postneonatal etiology (n = 766). Birth weight, gestational age, and race/ethnicity subanalyses were restricted to children with spastic CP (n = 640). Trends were examined by CP subtype, gender, race/ethnicity, co-occurring DDs, birth weight, and gestational age.

RESULTS

Birth prevalence of spastic CP per 1000 1-year survivors was stable from 1985 to 2002 (1.9 in 1985 to 1.8 in 2002; 0.3% annual average prevalence; 95% confidence interval [CI] -1.1 to 1.8). Whereas no significant trends were observed by gender, subtype, birth weight, or gestational age overall, CP prevalence with co-occurring moderate to severe intellectual disability significantly decreased (-2.6% [95% CI -4.3 to -0.8]). Racial disparities persisted over time between non-Hispanic black and non-Hispanic white children (prevalence ratio 1.8 [95% CI 1.5 to 2.1]). Different patterns emerged for non-Hispanic white and non-Hispanic black children by birth weight and gestational age.

CONCLUSIONS

Given improvements in neonatal survival, evidence of stability of CP prevalence is encouraging. Yet lack of overall decreases supports continued monitoring of trends and increased research and prevention efforts. Racial/ethnic disparities, in particular, warrant further study.

Prevalence and impact of unhealthy weight in a national sample of US adolescents with autism and other learning and behavioral disabilities

We estimated the prevalence of obesity, overweight, and underweight among US adolescents with and without autism and other learning and behavioral developmental disabilities (DDs) and assessed the health consequences of obesity among adolescents with DDs. From the 2008 to 2010 National Health Interview Survey, we selected 9,619 adolescents ages 12-17 years. Parent respondents reported weight, height, presence of DDs and health conditions. We calculated body mass index (BMI) and defined obesity, overweight, and underweight as ≥95th, ≥85th to <95th, and <5th percentiles, respectively, using established criteria. We created mutually-exclusive DD subgroups using the following order of precedence: autism; intellectual disability; attention-deficit-hyperactivity-disorder; learning disorder/other developmental delay. We compared BMI outcomes among adolescents in each DD group versus adolescents without DDs using multivariable logistic regression. Socio-demographic factors and birthweight were included as confounders. Estimates were weighted to reflect the US population. Both obesity and underweight prevalences were higher among adolescents with than without DDs [adjusted prevalence ratios (aPR) 1.5 (1.25-1.75) and 1.5 (1.01-2.20), respectively]. Obesity was elevated among adolescents with all DD types, and was highest among the autism subgroup [aPR 2.1 (1.44-3.16)]. Adolescents with either a DD or obesity had higher prevalences of common respiratory, gastrointestinal, dermatological and neurological conditions/symptoms than nonobese adolescents without DDs. Adolescents with both DDs and obesity had the highest estimates for most conditions. Obesity is high among adolescents with autism and other DDs and poses added chronic health risks. Obesity prevention and management approaches for this vulnerable population subgroup need further consideration.

Autism spectrum disorder symptoms among children enrolled in the Study to Explore Early Development (SEED)

This study examined the phenotypic profiles of children aged 30-68 months in the Study to Explore Early Development (SEED). Children classified as autism spectrum disorder (ASD), developmental delay (DD) with ASD symptoms, DD without ASD symptoms, and population comparison (POP) differed significantly from each other on cognitive, adaptive, behavioral, and social functioning and the presence of parent-reported conditions. Children with ASD and DD with ASD symptoms had mild to severe ASD risk on several measures compared to children with other DD and POP who had little ASD risk across measures. We conclude that children in SEED have varying degrees of ASD impairment and associated deficits. SEED thus provides a valuable sample to explore ASD phenotypes and inform risk factor analyses.

Does Autism Diagnosis Age or Symptom Severity Differ Among Children According to Whether Assisted Reproductive Technology was Used to Achieve Pregnancy?

Previous studies report associations between conception with assisted reproductive technology (ART) and autism. Whether these associations reflect an ascertainment or biologic effect is undetermined. We assessed diagnosis age and initial autism symptom severity among >30,000 children with autism from a linkage study of California Department of Developmental Services records, birth records, and the National ART Surveillance System. Median diagnosis age and symptom severity levels were significantly lower for ART-conceived than non-ART-conceived children. After adjustment for differences in the socio-demographic profiles of the two groups, the diagnosis age differentials were greatly attenuated and there were no differences in autism symptomatology. Thus, ascertainment issues related to SES, not ART per se, are likely the driving influence of the differences we initially observed.

The role of socio-economic status and perinatal factors in racial disparities in the risk of cerebral palsy

AIM

To determine whether racial disparities in cerebral palsy (CP) risk among US children persist after controlling for socio-economic status (SES) (here indicated by maternal education) and perinatal risk factors.

METHOD

A population-based birth cohort study was conducted using the Autism and Developmental Disabilities Monitoring Network surveillance and birth data for 8-year-old children residing in multi-county areas in Alabama, Georgia, Missouri, and Wisconsin between 2002 and 2008. The birth cohort comparison group included 458 027 children and the case group included 1570 children with CP, 1202 with available birth records. χ(2) tests were performed to evaluate associations and logistic regression was used to calculate relative risks (RR) and adjusted odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

The risk of spastic CP was more than 50% higher for black versus white children (RR 1.52, 95% CI 1.33-1.73), and this greater risk persisted after adjustment for SES (OR 1.35, 95% CI 1.18-1.55), but not after further adjustment for preterm birth and size for gestational age. The protective effect of maternal education remained after adjustment for race/ethnicity and perinatal factors.

INTERPRETATION

Maternal education appears to independently affect CP risk but does not fully explain existing racial disparities in CP prevalence in the US.

Age at Autism Spectrum Disorder (ASD) Diagnosis by Race, Ethnicity, and Primary Household Language Among Children with Special Health Care Needs, United States, 2009-2010

We examined prevalence of diagnosed autism spectrum disorder (ASD) and age at diagnosis according to child's race/ethnicity and primary household language. From the 2009-2010 National Survey of Children with Special Health Care Needs, we identified 2729 3-17-year-old US children whose parent reported a current ASD diagnosis. We compared ASD prevalence, mean diagnosis age, and percentage with later diagnoses (≥5 years) across racial/ethnic/primary household language groups: non-Hispanic-white, any language (NHW); non-Hispanic-black, any language (NHB); Hispanic-any-race, English (Hispanic-English); and Hispanic-any-race, other language (Hispanic-Other). We assessed findings by parent-reported ASD severity level and adjusted for family sociodemographics. ASD prevalence estimates were 15.3 (NHW), 10.4 (NHB), 14.1 (Hispanic-English), and 5.2 (Hispanic-Other) per 1000 children. Mean diagnosis age was comparable across racial/ethnic/language groups for 3-4-year-olds. For 5-17-year-olds, diagnosis age varied by race/ethnicity/language and also by ASD severity. In this group, NHW children with mild/moderate ASD had a significantly higher proportion (50.8 %) of later diagnoses than NHB (33.5 %) or Hispanic-Other children (18.0 %). However, NHW children with severe ASD had a comparable or lower (albeit non-significant) proportion (16.4 %) of later diagnoses than NHB (37.8 %), Hispanic-English (30.8 %), and Hispanic-Other children (12.0 %). While NHW children have comparable ASD prevalence and diagnosis age distributions as Hispanic-English children, they have both higher prevalence and proportion of later diagnoses than NHB and Hispanic-Other children. The diagnosis age findings were limited to mild/moderate cases only. Thus, the prevalence disparity might be primarily driven by under-representation (potentially under-identification) of older children with mild/moderate ASD in the two minority groups.

Trends in the prevalence of autism spectrum disorder, cerebral palsy, hearing loss, intellectual disability, and vision impairment, metropolitan atlanta, 1991-2010

This study examined the prevalence and characteristics of autism spectrum disorder (ASD), cerebral palsy (CP), hearing loss (HL), intellectual disability (ID), and vision impairment (VI) over a 15-20 year time period, with specific focus on concurrent changes in ASD and ID prevalence. We used data from a population-based developmental disabilities surveillance program for 8-year-olds in metropolitan Atlanta. From 1991-2010, prevalence estimates of ID and HL were stable with slight increases in VI prevalence. CP prevalence was constant from 1993-2010. The average annual increase in ASD prevalence was 9.3% per year from 1996-2010, with a 269% increase from 4.2 per 1,000 in 1996 to 15.5 per 1,000 in 2010. From 2000-2010, the prevalence of ID without ASD was stable; during the same time, the prevalence of ASD with and without co-occurring ID increased by an average of 6.6% and 9.6% per year, respectively. ASD prevalence increases were found among both males and females, and among nearly all racial/ethnic subgroups and levels of intellectual ability. Average annual prevalence estimates from 1991-2010 underscore the significant community resources needed to provide early intervention and ongoing supports for children with ID (13.0 per 1,000), CP, (3.5 per 1,000), HL (1.4 per 1,000) and VI (1.3 in 1,000), with a growing urgency for children with ASD.

Association of assisted reproductive technology (ART) treatment and parental infertility diagnosis with autism in ART-conceived children

STUDY QUESTION

Are assisted reproductive technology (ART) treatment factors or infertility diagnoses associated with autism among ART-conceived children?

SUMMARY ANSWER

Our study suggests that the incidence of autism diagnosis in ART-conceived children during the first 5 years of life was higher when intracytoplasmic sperm injection (ICSI) was used compared with conventional IVF, and lower when parents had unexplained infertility (among singletons) or tubal factor infertility (among multiples) compared with other types of infertility.

WHAT IS KNOWN ALREADY

Some studies found an increased risk of autism among ART-conceived infants compared with spontaneously-conceived infants. However, few studies, and none in the USA, have examined the associations between types of ART procedures and parental infertility diagnoses with autism among ART-conceived children.

STUDY DESIGN, SIZE, DURATION

Population-based retrospective cohort study using linkages between National ART Surveillance System (NASS) data for 1996-2006, California Birth Certificate data for 1997-2006, and California Department of Developmental Services (DDS) Autism Caseload data for 1997-2011.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All live born ART-conceived infants born in California in 1997-2006 (n = 42 383) with 5-year observation period were included in the study. We assessed the annual incidence of autism diagnosis documented in DDS, which includes information on the vast majority of persons with autism in California, and the association of autism diagnosis with ART treatment factors and infertility diagnoses.

MAIN RESULTS AND THE ROLE OF CHANCE

Among ART-conceived singletons born in California between 1997 and 2006, the incidence of autism diagnosis remained at ∼0.8% (P for trend 0.19) and was lower with parental diagnosis of unexplained infertility (adjusted hazard risk ratio [aHRR]; 95% confidence interval: 0.38; 0.15-0.94) and higher when ICSI was used (aHRR 1.65; 1.08-2.52), when compared with cases without these patient and treatment characteristics. Among ART-conceived multiples, the incidence of autism diagnosis between 1997 and 2006 remained at ∼1.2% (P for trend 0.93) and was lower with parental diagnosis of tubal factor infertility (aHRR 0.56; 0.35-0.90) and higher when ICSI was used (aHRR 1.71; 1.10-2.66).

LIMITATIONS, REASONS FOR CAUTION

Study limitations include imperfect data linkages, lack of data on embryo quality and possible underestimation of autism diagnosis cases. Limitations of the observational study design could affect the analysis by the possibility of residual confounders. Since information about ICSI use was missing for most frozen/thawed embryo transfer cycles, our findings of association of ICSI use and autism diagnosis can only be generalizable to fresh embryo transfer cycles.

WIDER IMPLICATIONS OF THE FINDINGS

Our study provides additional evidence of the association between some types of ART procedures with autism diagnosis. Additional research is required to explain the increased risk of autism diagnosis with ICSI use, as well as studies on the effectiveness and safety of ICSI.

Urbanicity and autism spectrum disorders

The etiology of autism spectrum disorders (ASD) is for the majority of cases unknown and more studies of risk factors are needed. Geographic variation in ASD occurrence has been observed, and urban residence has been suggested to serve as a proxy for etiologic and identification factors in ASD. We examined the association between urbanicity level and ASD at birth and during childhood. The study used a Danish register-based cohort of more than 800,000 children of which nearly 4,000 children were diagnosed with ASD. We found a dose-response association with greater level of urbanicity and risk of ASD. This association was found for residence at birth as well as residence during childhood. Further, we found an increased risk of ASD in children who moved to a higher level of urbanicity after birth. Also, earlier age of ASD diagnosis in urban areas was observed. While we could not directly examine the specific reasons behind these associations, our results demonstrating particularly strong associations between ASD diagnosis and post-birth migration suggest the influence of identification-related factors such as access to services might have a substantive role on the ASD differentials we observed.

Complications in the first 5 years following cataract surgery in infants with and without intraocular lens implantation in the Infant Aphakia Treatment Study

PURPOSE

To compare rates and severity of complications between infants undergoing cataract surgery with and without intraocular lens (IOL) implantation.

DESIGN

Prospective randomized clinical trial.

METHODS

A total of 114 infants were enrolled in the Infant Aphakia Treatment Study, a randomized, multi-center (12) clinical trial comparing the treatment of unilateral aphakia in patients under 7 months of age with a primary IOL implant or contact lens. The rate, character, and severity of intraoperative complications, adverse events, and additional intraocular surgeries during the first 5 postoperative years in the 2 groups were examined.

RESULTS

There were more patients with intraoperative complications (28% vs 11%, P = .031), adverse events (81% vs 56%, P = .008), and more additional intraocular surgeries (72% vs 16%, P < .0001) in the IOL group than in the contact lens group. However, the number of patients with adverse events in the contact lens group increased (15 to 24) in postoperative years 2-5 compared to the first postoperative year, while it decreased (44 to 14) in years 2-5 compared to the first postoperative year in the IOL group. If only one half of the patients in the contact lens (aphakic) group eventually undergo secondary IOL implantation, the number of additional intraocular surgeries in the 2 groups will be approximately equal.

CONCLUSION

The increased rate of complications, adverse events, and additional intraocular surgeries associated with IOL implantation in infants <7 months of age militates toward leaving babies aphakic if it is considered likely that the family will be successful with contact lens correction.

Population attributable fractions for three perinatal risk factors for autism spectrum disorders, 2002 and 2008 autism and developmental disabilities monitoring network

PURPOSE

Numerous studies establish associations between adverse perinatal outcomes/complications and autism spectrum disorder (ASD). There has been little assessment of population attributable fractions (PAFs).

METHODS

We estimated average ASD PAFs for preterm birth (PTB), small for gestational age (SGA), and Cesarean delivery (CD) in a U.S. population. Average PAF methodology accounts for risk factor co-occurrence. ASD cases were singleton non-Hispanic white, non-Hispanic black, and Hispanic children born in 1994 (n = 703) or 2000 (n = 1339) who resided in 48 U.S. counties included within eight Autism and Developmental Disabilities Monitoring Network sites. Cases were matched on birth year, sex, and maternal county of residence, race-ethnicity, age, and education to 20 controls from U.S. natality files.

RESULTS

For the 1994 cohort, average PAFs were 4.2%, 0.9%, and 7.9% for PTB, SGA, and CD, respectively. The summary PAF was 13.0% (1.7%-19.5%). For the 2000 cohort, average PAFs were 2.0%, 3.1%, and 6.7% for PTB, SGA, and CD, respectively, with a summary PAF of 11.8% (7.5%-15.9%).

CONCLUSIONS

Three perinatal risk factors notably contribute to ASD risk in a U.S. population. Because each factor represents multiple etiologic pathways, PAF estimates are best interpreted as the proportion of ASD attributable to having a suboptimal perinatal environment resulting in PTB, SGA, and/or CD.

Exclusion of progressive brain disorders of childhood for a cerebral palsy monitoring system: a public health perspective

BACKGROUND

Cerebral palsy (CP) is defined by its nonprogressive features. Therefore, a standard definition and list of progressive disorders to exclude would be useful for CP monitoring and epidemiologic studies.

METHODS

We reviewed the literature on this topic to 1) develop selection criteria for progressive brain disorders of childhood for public health surveillance purposes, 2) identify categories of disorders likely to include individual conditions that are progressive, and 3) ascertain information about the relative frequency and natural history of candidate disorders.

RESULTS

Based on 19 criteria that we developed, we ascertained a total of 104 progressive brain disorders of childhood, almost all of which were Mendelian disorders.

DISCUSSION

Our list is meant for CP surveillance programs and does not represent a complete catalog of progressive genetic conditions, nor is the list meant to comprehensively characterize disorders that might be mistaken for cerebral palsy. The criteria for progressive disorders that we developed could be applied by public health investigators in the future, as more children with very rare conditions are followed and new candidate disorders are identified.

Maternal infections during pregnancy and cerebral palsy: a population-based cohort study

BACKGROUND

Cerebral palsy (CP) is a common motor disability in childhood. We examined the association between maternal infections during pregnancy and the risk of congenital CP in the child.

METHODS

Liveborn singletons in Denmark between 1997 and 2003 were identified from the Danish National Birth Registry and followed from 1 year of life until 2008. Redemption of antibiotics from the National Register of Medicinal Product Statistics and maternal infections reported by the National Hospital Register were used as markers of maternal infection during pregnancy. CP diagnoses were obtained from the Danish Cerebral Palsy Registry. Adjusted hazard ratio (HR) and 95% confidence interval (CI) were estimated by Cox proportional hazard models.

RESULTS

Of the 440 564 singletons with follow-up data, 840 were diagnosed with congenital CP. Maternal genito-urinary tract infections (HR 2.1, 95% CI 1.4, 3.2) were associated with CP in all births, in term births (HR 1.9, 95% CI 1.1, 3.2), in children with spastic CP (HR 2.1, 95% CI 1.4, 3.3), and among first-born children (HR 1.9, 95% CI 1.4, 3.3). Overall, we found associations between redeemed nitrofurantoin (HR 1.7, 95% CI 1.1, 2.8) and CP. Among trimester-specific exposures, CP risk was associated with prescriptions redeemed in the first trimester for any antibacterials, beta-lactam antibacterials, and nitrofurantoin, an antibiotic commonly used to treat lower urinary tract infection, and genito-urinary tract infections in the third trimester.

CONCLUSION

Genito-urinary tract infections and antibiotic use during pregnancy were associated with increased risks of CP, indicating that some maternal infections or causes of maternal infections present in prenatal life may be part of a causal pathway leading to CP.

Congenital cerebral palsy and prenatal exposure to self-reported maternal infections, fever, or smoking

OBJECTIVE

The objective of the study was to investigate the association between maternal self-reported infections, fever, and smoking in the prenatal period and the subsequent risk for congenital cerebral palsy (CP).

STUDY DESIGN

We included the 81,066 mothers of singletons born between 1996 and 2003 who participated in the Danish National Birth Cohort. Children were followed up through December 2008. Information on maternal infections, fever, smoking, and other demographic and lifestyle factors during pregnancy were reported by mothers in computer-assisted telephone interviews in early and midgestation. We identified 139 CP cases including 121 cases of spastic CP (sCP) as confirmed by the Danish National Cerebral Palsy Register. Cox proportional hazards regression models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

Self-reported vaginal infections were associated with an increased risk of CP and sCP (aHR, 1.52; 95% CI, 1.04-2.24; and aHR, 1.73; 95% CI, 1.16-2.60, respectively) and particularly untreated vaginal infections were associated with an increased risk of sCP (aHR, 1.95; 95% CI, 1.16-3.26). Fever was associated with the risk of CP (aHR, 1.53; 95% CI, 1.06-2.21). Smoking 10 or more cigarettes per day during pregnancy was also associated with sCP (aHR, 1.80; 95% CI, 1.10-2.94). There was a modest excess in risk for children exposed to both heavy smoking and vaginal infections. No other self-reported infections were significantly associated with CP.

CONCLUSION

Self-reported vaginal infections, fever, and smoking 10 or more cigarettes per day during pregnancy were associated with a higher risk of overall CP and/or sCP.

Childhood vision impairment, hearing loss and co-occurring autism spectrum disorder

BACKGROUND

Limited population-based data on prevalence of childhood vision impairment (VI) and hearing loss (HL), and their co-occurrence with autism spectrum disorder (ASD) exists.

OBJECTIVE

To examine prevalence and characteristics of VI, HL and co-occurring ASD among 8-year-olds in metropolitan Atlanta 2000-2008.

METHODS

We used data from the population-based Metropolitan Atlanta Developmental Disabilities Surveillance Program. Prevalence, birth and parental characteristics, presence and severity of other co-occurring developmental disabilities, and age of earliest identification of ASD, were examined for children with VI and HL, by co-occurring ASD.

RESULTS

VI and HL prevalences were 1.2 and 1.3 per 1000 8-year-olds, respectively. Approximately 6-7% of children with VI or HL had co-occurring ASD. Children with VI or HL with co-occurring ASD differed from those without co-occurring ASD by select birth characteristics and the presence of other co-occurring DDs. The median age of earliest known ASD diagnosis was significantly later among children with VI and ASD compared to children with ASD without VI (79 vs. 56 months). Children with HL and ASD were first evaluated by a community provider significantly earlier than those with ASD without HL (40 vs. 50 months).

CONCLUSIONS

The frequency of co-occurring ASD with VI and HL is higher than the population prevalence of ASD. The significant delays in diagnosis of ASD in children with VI and lack of earlier diagnosis of ASD among children with HL despite earlier evaluation highlight the importance of developing screening tools for early identification of ASD among children with VI and HL.

The role of migration and choice of denominator on the prevalence of cerebral palsy

AIM

Differential migration and choice of denominator have been hypothesized to contribute to differences between period prevalence and birth prevalence of cerebral palsy (CP). The purpose of this study was to evaluate the effects of migration and choice of denominator on the prevalence of CP.

METHOD

Data from the Metropolitan Atlanta Developmental Disabilities Surveillance Program and census and birth certificate files were used to calculate various CP prevalence estimates for 2000.

RESULTS

The overall CP period prevalence was 3.2 (95% confidence interval [CI] 2.7-3.8) per 1000 8-year-olds and was similar for those born in Atlanta who resided there at age 8 years (3.3; 95% CI 2.7-4.1) and those born outside Atlanta who moved into Atlanta by age 8 years (3.0; 95% CI 2.3-3.9). CP prevalence in these two migration strata was similar by sex and race/ethnicity. CP birth prevalence of 8-year-olds in Atlanta in 2000 was 2.0 (95% CI 1.6-2.5) per 1000 live births in 1992.

INTERPRETATION

The authors found no evidence to support the hypothesis that differential in-migration explained higher period than birth prevalence of CP in Atlanta. Comparability of CP prevalence across geographic areas will be enhanced if future studies report both period and birth prevalence.

Dental care among young adults with intellectual disability

Dental care among young adults with intellectual disability (ID) is poorly documented and largely unmet. By using population-based data from the Metropolitan Atlanta Developmental Disabilities Follow-Up Study, we assessed factors associated with at least one or two dental visits per year among young adults with and without ID. Significantly fewer young adults with ID (45%) visited a dentist at least once per year, compared with those without ID (58%). ID severity and the presence of co-occurring developmental disabilities predicted dental care use. Sociodemographics, daily functioning, societal participation, dental services, and dental health factors were examined as predictors of dental care frequency. Our findings can help focus efforts toward improving the frequency of dental care visits among young adults with ID.

The Study to Explore Early Development (SEED): a multisite epidemiologic study of autism by the Centers for Autism and Developmental Disabilities Research and Epidemiology (CADDRE) network

The Study to Explore Early Development (SEED), a multisite investigation addressing knowledge gaps in autism phenotype and etiology, aims to: (1) characterize the autism behavioral phenotype and associated developmental, medical, and behavioral conditions and (2) investigate genetic and environmental risks with emphasis on immunologic, hormonal, gastrointestinal, and sociodemographic characteristics. SEED uses a case-control design with population-based ascertainment of children aged 2-5 years with an autism spectrum disorder (ASD) and children in two control groups-one from the general population and one with non-ASD developmental problems. Data from parent-completed questionnaires, interviews, clinical evaluations, biospecimen sampling, and medical record abstraction focus on the prenatal and early postnatal periods. SEED is a valuable resource for testing hypotheses regarding ASD characteristics and causes.