Screening for Autism Spectrum Disorders in Very Low Birth Weight Preterm Infants

Background:  Very low birth weight preterm infants are a high-risk group for ASD, although there is no agreement about the rate. ASD signs can be detected earlier in infancy, but screening that population in different moments can lead to different results, due to developmental delays that may be present.

Objectives:  to screen very low birth weight preterm infants for ASD signs between 18 and 24 month of corrected age, and reassess the sample, 12 month later in order to verify the permanence or not of the ASD signs.

Methods:  60 families of very low birth weight preterm infants between 18 and 24 month of corrected age answered the M-CHAT questionnaire (Robins et al, 2001). After 12 months, the same families answered de ABC questionnaire (Krug et al, 1980). 

Results:  Screening the very low birth weight preterm infants at 18 to 24 month found a rate of 6,7% of positive results for ASD. A second screening, performed one year later found a rate of 5,2% of positive results, although not all the same children of the first evaluation presented those signs: in the first screening with M-CHAT, girls and boys had positive screening for ASD signs, and in the second screening, with the ABC questionnaire, only boys. Comparison of the positive screening results in both moments, show a low degree of agreement between the questionnaires, Fisher test, p=0,196, Kappa agreement coefficient =0,241 (p=0,063). Positive-screening children were evaluated by diagnosis protocol, and 3,5% of our sample met de DSM-5 (2013) criteria for ASD

Conclusions:  : Very low birth weight preterm infants are an ASD risk group; although the rates can be lower than former reports. Screening at age of 18 months allows identification of developmental delays, independently of a future ASD diagnosis. However, a single screening at this age, can lead to false-positive results, due to developmental delays common to the premature condition. A second screening, around 30 month of age is recommended, which also guaranties inclusion of regressive ASD cases.