Factors Contributing to Autism in Preterm Children Assessed
Preterm births may have higher risk of autism due to prenatal and neonatal complications
WEDNESDAY, Oct. 21 (HealthDay News) -- The higher risk of autistic disorders related to premature birth may be largely due to higher rates of prenatal and neonatal complications, according to research completed in Sweden and published online Oct. 19 in Pediatrics.
Susanne Buchmayer, M.D., of the Karolinska Institute in Stockholm, Sweden, and colleagues analyzed data from a case-control study of 1,216 subjects with autistic disorders born between 1987 and 2002, and 6,080 matched controls.
The researchers found that subjects born very or moderately preterm had a higher risk of autistic disorders (odds ratios, 2.05 and 1.55, respectively). Adjustment for neonatal and prenatal factors resulted in odds ratios of 0.98 and 1.25, respectively. The increased risk in preterm children could be explained by maternal morbidity, birth factors, and neonatal complications. Women with preeclampsia had a greater than 50 percent risk of autism in offspring. In addition, factors such as intracranial bleeding, cerebral edema, or seizures greatly increased autistic risk.
"The increased risk of autistic disorders related to preterm birth is mediated primarily by prenatal and neonatal complications that occur more commonly among preterm infants," the authors conclude. "Our study also indicates that there may be differences in risk factors for autistic disorders among preterm and term infants."