Original articlePopulation impact of preterm birth and low birth weight on developmental disabilities in US children
Introduction
Developmental disabilities (DDs) are chronic conditions associated with significant impairments in physical, cognitive, behavioral, and/or speech/language functioning. The prevalence of DDs in US children is estimated at 15% overall [1] and ranges from less than 1% (e.g., cerebral palsy [CP]) [2] to 9% (e.g., attention-deficit-hyperactivity disorder [ADHD]) [3]. In addition to functional limitations, children with DDs have increased prevalence of many health conditions including asthma, eczema, gastrointestinal disorders, and obesity [4], [5]. Although the causes of a few DDs are well defined (e.g., intellectual disability [ID] linked to select genetic conditions or fetal alcohol syndrome), for most DDs, etiology is complex and multifactorial [6], [7], [8], [9], [10].
Although numerous studies document associations between preterm birth (PTB) and low birth weight (LBW) and DDs such as CP [8], [11], [12], ID [12], [13], [14], [15], [16], [17], autism spectrum disorder (ASD) [12], [13], [18], ADHD [12], [19], [20], learning disability (LD) [12], [21], and general developmental delay [12], [22], [23], there is limited assessment of population impacts. Studies of population attributable fractions (PAFs) in US populations include an assessment of the Georgia Pregnancy Risk Assessment Monitoring System which estimated 42% of CP cases and 13% of ID cases were attributable to LBW [24], an assessment of North Dakota registry data which estimated 8% of ASD cases were attributable to low gestation and 8% were attributable to LBW [25], and an assessment of the Autism and Developmental Disabilities Monitoring Network which estimated 12% of ASD cases were attributable to PTB, LBW, and Cesarean delivery [26]. Studies from other countries of the impacts of various pregnancy complications and/or outcomes on ASD [27], ADHD [20], and developmental delays [28] reported moderate PAFs for the various perinatal factors studied. These past studies had notable limitations. Most did not assess the known overlap between the perinatal factors studied, all only assessed one or two DDs, and none assessed potential effects from co-occurring DDs. A high proportion of children with DDs meet diagnostic criteria for multiple DDs [29], [30]. Boulet et al. [29] reported that 43%–96% of US children with specific DD diagnoses had more than one DD diagnosis.
Using data from the 2011–2012 National Survey of Children's Health (NSCH), we assessed associations and population impacts of PTB and LBW on subsequent DDs including CP, ID, ASD, ADHD, LD, behavioral or conduct problems or disorder (BCD), and other developmental delay. In addition to assessing a broad array of DDs side by side, we designed analyses to account for DD co-occurrence and examined a finer gradation of PTB and LBW risk than prior studies. To our knowledge, this is the largest and most comprehensive assessment of PAFs for DDs in a US population and the first-to-consider DD co-occurrence.
Section snippets
Study population
The NSCH is a periodic random-digit-dial health survey of US noninstitutionalized children. Households are the primary sampling unit; from contacted households with children, one child is randomly selected. The survey is administered to a parent or guardian knowledgeable about the selected child's health. The overall response rate for the 2011–2012 NSCH was 23% [31]. Nonresponse was more common for cell-phone numbers than landlines. Among contacted households with children, the interview
Results
Overall, 13.9% of children had one or more DD. Individual estimates ranged from 0.24% for CP to 8.2% for ADHD (Table 1). The percentage range for mutually exclusive DD categories was narrower: 0.24% for CP to 5.6% for ADHD. Overall, 49% of children with DDs had greater than 1 DD and 23% had greater than 2 DDs. Thus, only 57% of children with ID, 34% of children with LD, and 13% of children with other developmental delay, were included in the respective mutually exclusive groups for these DDs.
Discussion
In this US nationally representative sample of children, PTB explained more than 50% of CP diagnoses, 15%–20% of ID and other developmental delay diagnoses, and 10%–15% of ASD and LD diagnoses. For CP, both aRRs and component PAFs showed a dose-response pattern: VLBW-PTBs explained substantially more CP than MLBW-PTBs, which explained substantially more CP than NBW-PTBs. For ASD, ID, LD, and other developmental delay, the VLBW-Preterm, MLBW-Preterm, and NBW-Preterm contributions were more
Conclusion
Despite recent declines, PTB remains common; 11.6% of US births in 2012 were preterm and 3.4% were very preterm (<37 and <34-week gestation, respectively) [34]. This study demonstrates the sizable contribution of PTB on child neurodevelopment. Efforts to control PTB are complex. Moreover, while our findings are informative on a population level, they do not indicate which PTB etiologic subgroups most contribute to the associations between PTB and DDs. Nonetheless, these findings highlight the
Acknowledgment
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease and Control and Prevention.
References (40)
- et al.
Trends in the parent-report of health care provider-diagnosed and medicated attention-deficit/hyperactivity disorder: United States, 2003-2011
J Am Acad Child Adolesc Psychiatry
(2014) - et al.
Concurrent medical conditions and health care use and needs among children with learning and behavioral developmental disabilities, National Health Interview Survey, 2006-2010
Res Dev Disabil
(2012) - et al.
Have secular changes in perinatal risk factors contributed to the recent autism prevalence increase? Development and application of a mathematical assessment model
Ann Epidemiol
(2011) - et al.
Developmental delay in moderately preterm-born children with low socioeconomic status: risks multiply
J Pediatr
(2013) - et al.
A comparison of the effects of parental risk markers on pre- and perinatal variables in multiple patient cohorts with fetal alcohol syndrome, autism, Tourette syndrome, and sudden infant death syndrome: an enviromic analysis
Neurotoxicol Teratol
(2003) - et al.
Population attributable fractions for three perinatal risk factors for autism spectrum disorders, 2002 and 2008 Autism and Developmental Disabilities Monitoring Network
Ann Epidemiol
(2014) - et al.
Obstetric risk factors and autism spectrum disorders in Finland
J Pediatr
(2014) - et al.
Associations of preterm births with child health and development: Japanese population-based study
J Pediatr
(2013) Concepts and pitfalls in measuring and interpreting attributable fractions, prevented fractions, and causation probabilities
Ann Epidemiol
(2015)- et al.
Trends in the prevalence of developmental disabilities in US children 1997-2008
Pediatrics
(2011)
Trends in the prevalence of autism spectrum disorder, cerebral palsy, hearing loss, intellectual disability, and vision impairment, metropolitan Atlanta, 1991-2010
PLOS One
Prevalence and impact of unhealthy weight in a national sample of US adolescent children with autism and other learning and behavioral disabilities
Matern Child Health J
What have we learnt about the causes of ADHD?
J Child Psychol Psychiatry
Changing concepts and findings on autism
J Autism Dev Disord
A systematic review of risk factors for cerebral palsy in children born at term in developed countries
Dev Med Child Neurol
Genetic causes of developmental disorders
Curr Opin Neurol
Understanding the complex etiologies of developmental disorders: behavioral and molecular genetic approaches
J Dev Behav Pediatr
Prevalence, type, distribution, and severity of cerebral palsy in relation to gestational age: a meta-analytic review
Dev Med Child Neurol
Birth weight and health and developmental outcomes in US children, 1997-2005
Matern Child Health J
Comparison of perinatal risk factors associated with autism spectrum disorder (ASD), intellectual disability (ID), and co-occurring ASD and ID
J Autism Dev Disord
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