Screening for autism in very premature babies more accurate at 30 months

A large number of positive screens for autism spectrum disorder (ASD) at 18 months in infants who were born very preterm actually may be because of cognitive and language delay, according to research presented at the 2011 Pediatric Academic Societies meeting in Denver.

The American Academy of Pediatrics currently recommends screening all children aged 18 to 24 months for ASD; those who test positive should have a formal assessment.

Researchers studied the rate of positive ASD screens at 18 and 30 months in extremely preterm infants (born

Infants born extremely premature at Women and Infants Hospital of Rhode Island were followed at 18 and 30 months and screened. At 18 months, 152 children were screened; at 30 months, 116 were screened. A diagnostic assessment was completed in children with 1 or more positive screens at 30 months.

Eighteen percent of those screened for ASD at 18 months had at least 1 positive screen; 10% screened at 30 months had 1 or more positive tests. Positive screens at 18 or 30 months were linked to cognitive and language delay. All the children who had 3 positive screens at 30 months were diagnosed later with ASD.

The lower rate of screen positives for ASD at 30 months suggests that many positive 18-month screens could be false positives because of high rates of language and cognitive impairment, say the researchers. They acknowledge that although these findings indicate that later screening and multiple screening data points improve screening accuracy, further work is needed.

Researchers are seeking funding for a multicenter study of at least 500 preterm children in order to determine the true rate of ASD in this population, the rate of false-positive screens at 18 and 30 months, and the optimal time to screen infants for ASD.

Stephens BE, Watson VE, Tucker R, Sheinkopf SJ, Vohr BR. Screening for autism spectrum disorder at 18 vs. 30 months in extremely preterm infants. Poster presented at: Pediatric Academic Societies and Asian Society of Pediatric Research Joint Meeting; April 30-May 3, 2011; Denver, CO. Abstract 2705.2.