Autism spectrum disorders and prematurity: a review across gestational age subgroups

Autism spectrum disorders (ASDs) are increasingly recognized as a public health problem. According to the Centers for Disease Control and Prevention, the prevalence for ASD is now 1 in 88. The prevalence of ASDs in children has increased over the past 2 decades, nearly doubling the prevalence since the Centers for Disease Control and Prevention began tracking these numbers. Infants are defined as premature when birth takes place before 37 weeks' gestation (259 days from the first day of the mother's last menstrual period). More than 4 million live births occur in the United States each year. Preterm births account for approximately half a million of those births. The rate of premature birth has increased by more than 20% between 1990 and 2006. Cognitive impairment and atypical brain development are thought to be sequelae of preterm delivery. Low birth weight and preterm birth place these infants at higher risk for disturbances in social interaction, communication, and other psychoaffective disorders in adulthood. Major advances in the field of early autism detection include validated screening tools to facilitate early screening for children with ASD as well as those considered to be at high risk for the disorder. Given the significant maternal and neonatal morbidities that are often coupled with prematurity, understanding the prevalence and risk factors that are implicated in changes in the fetal brain may provide researchers with vital links to autism in this population.