%0 Journal Article %T Consistency between parent report and direct assessment of development in toddlers with autism spectrum disorder and other delays: Does sex assigned at birth matter? %A James S %A Hallur S %A Anbar J %A Matthews N %A Pierce K %A Smith CJ %J Autism Res %V 16 %N 6 %D 06 2023 3 %M 37009713 %F 4.633 %R 10.1002/aur.2927 %X The current study examined differences between parent report and diagnostician direct assessment of receptive language, expressive language, and fine motor abilities in toddlers with autism spectrum disorder (ASD) and other delays. Additionally, this study examined whether parent-diagnostician consistency varied by child diagnosis and sex assigned at birth (SAB). Initial mixed analysis of variances (ANOVAs) were conducted using data from a sample of 646 toddlers to examine whether parent-diagnostician consistency differed by child diagnosis. Matched samples (using child age, SAB, and nonverbal IQ) were then created within each diagnostic group and mixed ANOVAs were conducted to examine if consistency was similar in matched diagnostic subsamples and whether it differed by SAB. Findings from the full sample mostly replicated previous research that has documented consistency between parent report and direct observation regardless of child diagnosis. However, when examined in matched diagnostic subgroups, more nuanced patterns were observed. Parent report of receptive language was lower in ASD and ASD features subgroups and parent report of fine motor skills was lower than direct observation in the ASD, ASD features, and developmental delay groups. When examining the moderating effect of SAB, only expressive language was impacted for children in the ASD group. Results indicate the importance of considering child demographic characteristics and that child SAB may impact parent report and/or diagnostician perception of expressive language.