Birth Complications and Autism
The first scientific review of research on birth-related risk factors for autism has identified conditions that may contribute to the neurobiological disorder. Sixty different birth-related conditions were explored; the following thirteen conditions and complications were identified as having the strongest association with increased risk of autism: abnormal birth presentations (e.g., breech), umbilical-cord complications, fetal distress, birth injury or trauma, multiple birth, maternal bleeding, summer birth (possibly associated with pregnancy during winter flu season), low birth weight or small for gestational age, physical birth defects, low 5-minute Apgar score, myconium aspiration, feeding difficulties, and newborn anemia or hyperbilirubinemia. Many of the factors identified as increasing risk for autism were associated with hypoxia (low levels of oxygen in the brain). The review did not find an association between use of anesthesia during delivery, assisted vaginal delivery, post-term birth, high birth weight, and large or small head circumference and risk of autism. It is possible that risk may only be increased for infants who have suboptimal births in combination with genetic vulnerabilities. Pediatricians can use this information to better identify and monitor babies at risk for autism.
The study, entitled Perinatal and Neonatal Risk Factors for Autism: A Comprehensive Meta-analysis, was published online July, 11, 2011 in the journal Pediatrics.
(http://pediatrics.aappublications.org/content/128/2/344)
