The prevalence of autism spectrum disorders (ASDs) has increased by nearly 10-fold in the last 2 decades, owing, in part, to earlier diagnosis by community practitioners. Now, a new study in the September 2010 issue of Pediatrics reports that signs of autism may be present as early as 1 month of age.

Researchers evaluated children who received care in the Neonatal Intensive Care Unit (NICU) to assess the early markers and diagnosis of ASD. The authors retrospectively analyzed data from an 11-year period (1994-2005) and found 28 NICU graduates who later received an ASD diagnosis. These babies were matched with 112 age-, gender-, and birth cohort-matched controls who did not have an ASD diagnosis. The behavior and development of all the babies was assessed periodically until they were approximately 2 years old.

At 1 month of age, babies who later received an ASD diagnosis showed abnormal muscle tone and different visual processing performance than non-ASD babies. Specifically, muscle tone in the arms of the ASD babies was lacking, and visual tracking abilities were diminished. At 4 months of age, the babies who later received an ASD diagnosis preferred higher amounts of visual stimulation than control babies, a trait usually observed in newborns. By 7 to 10 months of age, babies later diagnosed with ASD exhibited declines in their motor skills and mental performance, resembling children with central nervous system impairments. By 13 months of age, the developmental patterns of children later diagnosed with ASD diverged markedly from control children without an ASD diagnosis.

If the findings of this study hold true among larger populations of children who did not receive care in the NICU, they may lead to earlier autism diagnoses — and earlier interventions. The better clinicians are able to understand and detect development disabilities, the sooner children and families can receive the care and support they need. The authors of the Pediatrics study contend that intervention by age 2 offers the best outcome.

The incidence of disability and developmental delays among NICU graduates is high, owing to a large number of preterm and low birth weight babies. Such babies have immature and underdeveloped sensory systems, and these systems mature subjected to environmental stress that healthy weight, full term infants do not experience. Therefore, early ways to identify and mitigate developmental and sensory deficits are paramount in the NICU. The gestational age and birth weight of the current cohort was not evaluated, limiting the interpretation of the results to larger, more general populations of babies.

Autism has become an increasingly prevalent public health concern, with approximately 1% of children reporting an ASD diagnosis. The signs of ASD, including atypical social interaction, communication, and behavior, are typically present by 3 years of age, with estimated peak prevalence around 8 years old. Most clinicians and experts believe that autism is the result of genetic factors, environmental influences, and timing. However, there is no identified genetic marker for autism and no environmental triggers have been confirmed. Still, the burden is real, in both economic and emotional terms.

The new study does not advocate that parents of newborns assess muscle tone and visual tracking in 1-month-old infants, but it does emphasize that any parent who is concerned about the development of his or her child should have the child evaluated by a clinician. Continued research is needed to uncover the risk factors and causes of autism, as well as provide support for patients, families, and communities living with ASD.

References

Autism and Developmental Disabilities Monitoring Network Surveillance Year 2006 Principal Investigators, & Centers for Disease Control and Prevention (CDC) (2009). Prevalence of autism spectrum disorders – Autism and Developmental Disabilities Monitoring Network, United States, 2006. MMWR. Surveillance summaries : Morbidity and mortality weekly report. Surveillance summaries / CDC, 58 (10), 1-20 PMID: 20023608

Karmel BZ, Gardner JM, Meade LS, Cohen IL, London E, Flory MJ, Lennon EM, Miroshnichenko I, Rabinowitz S, Parab S, Barone A, & Harin A (2010). Early Medical and Behavioral Characteristics of NICU Infants Later Classified With ASD. Pediatrics, 126 (3), 457-67 PMID: 20679296

Stoltenberg C, Schjølberg S, Bresnahan M, Hornig M, Hirtz D, Dahl C, Lie KK, Reichborn-Kjennerud T, Schreuder P, Alsaker E, Øyen AS, Magnus P, Surén P, Susser E, Lipkin WI, & ABC Study Group (2010). The Autism Birth Cohort: a paradigm for gene-environment-timing research. Molecular psychiatry, 15 (7), 676-80 PMID: 20571529

Vandenberg KA (2007). Individualized developmental care for high risk newborns in the NICU: a practice guideline. Early human development, 83 (7), 433-42 PMID: 17467932