Maternal Conditions and Perinatal Characteristics Associated with Autism Spectrum Disorder and Intellectual Disability
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As well as being highly comorbid conditions, autism spectrum disorders (ASD) and intellectual disability (ID) share a number of clinically-relevant phenomena. This raises questions about similarities and overlap in diagnosis and aetiological pathways that may exist for both conditions.
To examine maternal conditions and perinatal factors for children diagnosed with an ASD, with or without ID, and children with ID of unknown cause, compared with unaffected children.
The study population comprised all live singleton births in Western Australia (WA) between January 1984 and December 1999 (N = 383,153). Univariate and multivariate multinomial logistic regression models were applied using a blocked modelling approach to assess the effect of maternal conditions, sociodemographic factors, labour and delivery characteristics and neonatal outcomes.
In univariate analyses mild-moderate ID was associated with
urinary tract infection,
some types of ante-partum haemorrhage,
any type of preterm birth,
poor fetal growth and
need for resuscitation at birth, with all factors showing an increased risk.
Severe ID was positively associated with
poor fetal growth and
need for resuscitation,
as well as any labour or delivery complication.
In the multivariate analysis no maternal conditions or perinatal factors were associated with an increased risk of ASD without ID.
However, pregnancy hypertension and small head circumference were associated with a reduced risk (OR = 0.64, 95% CI: 0.43, 0.94; OR = 0.58, 95% CI: 0.34, 0.96, respectively).
For ASD with ID, threatened abortion before 20 weeks gestation and poor fetal growth were associated with an increased risk.
Findings show that indicators of a poor intrauterine environment are associated with an elevated risk of ID, while for ASD, and particularly ASD without ID, the associations are much weaker.
As such, these findings highlight the importance of accounting for the absence or presence of ID when examining ASD, if we are to improve our understanding of the causal pathways associated with these conditions.
Citation: Langridge AT, Glasson EJ, Nassar N, Jacoby P, Pennell C, et al. (2013) Maternal Conditions and Perinatal Characteristics Associated with Autism Spectrum Disorder and Intellectual Disability. PLoS ONE 8(1): e50963. doi:10.1371/journal.pone.0050963
Editor: Olivier Baud, Hôpital Robert Debré, France
Received: April 27, 2012; Accepted: October 29, 2012; Published: January 7, 2013
Copyright: © 2013 Langridge et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: Funding was provided by the Australian National Health and Medical Research Council (NHMRC, http://www.nhmrc.gov.au) Program Grant (572742), NHMRC Research Fellowship (572568 to HL) and NHMRC Career Development Fellowship (632955 to NN). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.