Parental obesity and risk of autism spectrum disorder.
OBJECTIVE
The objective of the study was to investigate the associations among maternal prepregnancy BMI, paternal BMI, and the risk of autism spectrum disorders (ASDs) in children.


METHODS
The study sample of 92 909 children was derived from the population-based, prospective Norwegian Mother and Child Cohort Study. The age range was 4.0 through 13.1 (mean 7.4) years. Relative risks of ASDs were estimated by odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression models.


RESULTS
At the end of follow-up on December 31, 2012, 419 children in the study sample had been diagnosed with ASDs: 162 with autistic disorder, 103 with Asperger disorder, and 154 with pervasive developmental disorder not otherwise specified. Maternal obesity (BMI ≥30) was only weakly associated with ASD risk, whereas paternal obesity was associated with an increased risk of autistic disorder and Asperger disorder. The risk of autistic disorder was 0.27% (25 of 9267) in children of obese fathers and 0.14% (59 of 41 603) in children of fathers with normal weight (BMI <25), generating an adjusted OR of 1.73 (95% CI: 1.07-2.82). For Asperger disorder, analyses were limited to children aged ≥7 years (n = 50 116). The risk was 0.38% (18 of 4761) in children of obese fathers and 0.18% (42 of 22 736) in children of normal-weight fathers, and the adjusted OR was 2.01 (95% CI: 1.13-3.57). No associations were found for pervasive developmental disorder not otherwise specified.


CONCLUSIONS
Paternal obesity is an independent risk factor for ASDs in children. The associations should be investigated further in genetic and epigenetic studies.
Norwegian Institute of Public Health, Oslo, Norway; Centre for Paediatric Epidemiology and Biostatistics, UCL Institute of Child Health, London, United Kingdom; pal.suren@fhi.no.
Pål
P
Surén
Norwegian Institute of Public Health, Oslo, Norway; Mailman School of Public Health, Columbia University, New York, New York;
Nina
N
Gunnes
Norwegian Institute of Public Health, Oslo, Norway; Mailman School of Public Health, Columbia University, New York, New York;
Christine
C
Roth
Mailman School of Public Health, Columbia University, New York, New York; New York State Psychiatric Institute, New York, New York;
Michaeline
M
Bresnahan
Mailman School of Public Health, Columbia University, New York, New York;
Mady
M
Hornig
National Institute of Neurologic Disorders and Stroke, Bethesda, Maryland;
Deborah
D
Hirtz
Norwegian Institute of Public Health, Oslo, Norway;
Kari Kveim
KK
Lie
Mailman School of Public Health, Columbia University, New York, New York;
W Ian
WI
Lipkin
Norwegian Institute of Public Health, Oslo, Norway;
Per
P
Magnus
Norwegian Institute of Public Health, Oslo, Norway; Institute of Psychiatry, University of Oslo, Oslo, Norway;
Ted
T
Reichborn-Kjennerud
Norwegian Institute of Public Health, Oslo, Norway;
Synnve
S
Schjølberg
Mailman School of Public Health, Columbia University, New York, New York; New York State Psychiatric Institute, New York, New York;
Ezra
E
Susser
Norwegian Institute of Public Health, Oslo, Norway; Nic Waals Institute, Lovisenberg Hospital, Oslo, Norway;
Anne-Siri
AS
Oyen
MRC Centre for Causal Analysis in Translational Epidemiology, University of Bristol, Bristol, United Kingdom; and.
George Davey
GD
Smith
Norwegian Institute of Public Health, Oslo, Norway; Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway.
Camilla
C
Stoltenberg
D000293:Adolescent; D020817:Asperger Syndrome / Q000453:epidemiology* / Q000209:etiology*; D015992:Body Mass Index; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000453:epidemiology* / Q000209:etiology*; D002675:Child, Preschool; D015331:Cohort Studies; D005220:Fathers; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D009035:Mothers; D009664:Norway; D009765:Obesity / Q000150:complications* / Q000453:epidemiology*; D016742:Preconception Care; D011446:Prospective Studies; D012306:Risk; D013223:Statistics as Topic
Asperger disorder; PDD-NOS; autism spectrum disorder; autistic disorder; child cohort study; parental BMI; parental obesity