Parent-mediated early intervention in infants and toddlers at elevated likelihood for autism: a systematic review of randomized controlled trials

The current prevalence of Autism Spectrum Disorder (ASD) has risen to 1 in 31, according to a recent report of the USA Centers for Disease Control and Prevention. While prodromal signs of ASD can be observed during the first months of life, most care approaches usually require a diagnosis before children can receive autism-specialized intervention services. A novel approach consists in providing parent-mediated intervention to infants higher likelihood for autism with the aim to decrease disability and perhaps impacting on developmental trajectory. The aim of this review is to summarize evidence on outcomes from Randomized Control Trials (RCTs) of parent-mediated early interventions in infants with very early ASD signs and/or with an elevated likelihood for ASD, in order to inform clinical practice. A systematic literature search was performed by using the following databases from 2014 until 17 February 2025: Pubmed, EMBASE, Scopus, Web of Science, OVID (PsycInfo). Papers were selected based on the following inclusion criteria: i) RCT studies; ii) Mean age of children enrolled in RCT studies <= 18 months; iii) English language published studies; iv) Infants presenting autistic signs or infants at elevated likelihood for ASD. Eleven studies were included and analyzed in regard to sample characteristics, enrollment strategies, outcome measures and intervention types.