Risk of Autism Spectrum Disorders in Low Birth Weight and Small for Gestational Age Infants

Objective To examine the relationship between birth weight, gestational age, small for gestational age (SGA), and 3 of the most common autism spectrum disorder (ASD) subtypes. Study design In this population-based case-control study conducted in Finland, 4713 cases born between 1987 and 2005 with International Classification of Diseases -diagnoses of childhood autism, Asperger syndrome, or pervasive developmental disorder (PDD), were ascertained from the Finnish Hospital Discharge Register. Four controls, individually matched on sex, date of birth, and place of birth, were selected from the Finnish Medical Birth Register for each case. Conditional logistic regression models were used to assess whether birth weight and gestational age information predicted ASD after controlling for maternal age, parity, smoking during pregnancy, and psychiatric history, as well as for infant's major congenital anomalies. Results Very low ( Conclusions The finding that low birth weight, prematurity, and SGA were related to childhood autism and PDD but not to Asperger syndrome suggests that prenatal factors related to these exposures may differ for these ASD subtypes, which may have preventive implications.