Detection of autism in infants prior to 18 months of age

Abstract

Introduction: In 2021, the third edition of the Child Health Booklet was published in Brazil, containing a positive novelty: the M-CHAT-R/F checklist, focused on the detection of Autism Spectrum Disorder (ASD) in children aged 16 to 30 months. The Booklet recommends screening for autism at the 18-month checkup. However, younger children have shown typical symptoms, such as delayed language development, non-responsiveness and lack of eye contact. In this regard, it is important to detect the signs of ASD early to diagnose and intervene as soon as possible. Objectives: To assess the feasibility of screening for autism in children under 18 months. Methods: Search terms were: “screening”, “autism” and “early detection”. Open articles in English and Spanish from 2013 to 2023 were selected in the PubMed and CAPES databases. We identified seven community-based papers in our review. Results: We found 9 tests able to early detect signs of autism: PREAUT (at 4 and/or 9 months), CIRTEA (0–12 months), FYI (6-16 months), ITC (6– 24 months), ADOS-2 (1 year to adult), TASI (12–36 months), SACS-R (12, 18, and 24 months consultations), CSBS-DP-IT (6–24 months) and M-CHAT-R/F (16–30 months). In the selected articles with Sensitivity (Se) data available, most tests used on infants under 1 year showed low sensitivity. However, early and repeated screening with a combination of tools facilitates early diagnosis and increases mean sensitivity: PREAUT at 4 and 9 months and CHAT at 24 resulted in a Se of 73%; CIRTEA + CHAT in a Se of 100% and SACS-R + SACS- PR (the latter at 31–60 months) in a Se of 96%. Conclusion: Despite the recommendation to screen for autism at 18 months, we found that screening can be done earlier, including in the first year of life. In addition, although mostly, a definitive diagnosis can’t be obtained at such an age, it is already possible to identify signs of atypical neurodevelopment in infants, and therefore allow earlier intervention.