Perinatal risk factors and infantile autism.
OBJECTIVE
Suboptimal conditions during pregnancy and birth have been suggested as a cause of infantile autism. We have studied the association between obstetric factors and infantile autism.


METHODS
A population-based, matched case-control study of infantile autism. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI).


RESULTS
The risk of infantile autism was increased for mothers aged >35 years, with foreign citizenship, and mothers who used medicine during pregnancy. A higher risk of infantile autism was seen among children with low birth weight and with congenital malformations. Birth interventions, pathological cardiotocography, green amnion fluid and acidosis during delivery were not associated with increased risk for infantile autism.


CONCLUSIONS
Our findings suggest that suboptimal birth conditions are not an independent risk factor for infantile autism. A high prevalence of low birth weight and birth defects among autism cases seems to explain the suboptimal birth outcome.
Maimburg
R D
RD
Department of Epidemiology and Social Medicine, Institute of Public Health, University of Aarhus, Vennelyst Boulevard 6, 8000 Aarhus C, Denmark. rmai@soci.au.dk
Vaeth
M
M
D000138:Acidosis / Q000453:epidemiology; D000653:Amniotic Fluid / Q000382:microbiology; D001321:Autistic Disorder / Q000453:epidemiology*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D015931:Intensive Care, Neonatal / Q000706:statistics & numerical data; D010500:Perinatology; D011159:Population Surveillance / Q000379:methods; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D012042:Registries; D012307:Risk Factors