BackgroundA growing body of research suggests that fine motor abilities are associated with skills in a variety of domains in both typical and atypical development. In this study, we investigated developmental trajectories of fine motor skills between 6 and 24 months in relation to expressive language outcomes at 36 months in infants at high and low familial risk for autism spectrum disorder (ASD).MethodsParticipants included 71 high-risk infants without ASD diagnoses, 30 high-risk infants later diagnosed with ASD, and 69 low-risk infants without ASD diagnoses. As part of a prospective, longitudinal study, fine motor skills were assessed at 6, 12, 18, and 24 months of age and expressive language outcomes at 36 months using the Mullen Scales of Early Learning. Diagnosis of ASD was determined at the infant’s last visit to the lab (18, 24, or 36 months) using the Autism Diagnostic Observation Schedule.ResultsHierarchical linear modeling revealed that high-risk infants who later developed ASD showed significantly slower growth in fine motor skills between 6 and 24 months, compared to their typically developing peers. In contrast to group differences in growth from age 6 months, cross-sectional group differences emerged only in the second year of life. Also, fine motor skills at 6 months predicted expressive language outcomes at 3 years of age.ConclusionsThese results highlight the importance of utilizing longitudinal approaches in measuring early fine motor skills to reveal subtle group differences in infancy between ASD high-risk and low-risk infant populations and to predict their subsequent language outcomes.Electronic supplementary materialThe online version of this article (10.1186/s11689-018-9231-3) contains supplementary material, which is available to authorized users.

We investigated gesture production in infants at high and low risk for autism spectrum disorder (ASD) and caregiver responsiveness between 12 and 24 months of age and assessed the extent to which early gesture predicts later language and ASD outcomes. Participants included 55 high-risk infants, 21 of whom later met criteria for ASD, 34 low-risk infants, and their caregivers. Results indicated that (a) infants with ASD outcomes used fewer gestures and a lower proportion of developmentally advanced gesture-speech combinations; (b) caregivers of all the infants provided similar rates of contingent responses to their infants' gestures; and (c) gesture production at 12 months predicted subsequent receptive language and ASD outcomes within the high-risk group.

We examined the language input of parents of infants at high and low familial risk for autism spectrum disorder (ASD) and investigated reciprocal associations between parent input and child language skills in the first 2 years of life. Parent‐infant dyads (high‐risk: n = 53; low‐risk: n = 33), 19 of whom included an infant later diagnosed with ASD, were videotaped during free play interactions at 12, 18, and 24 months. Measures of parent input were derived from parent–child interactions. Children's language skills were assessed using the Mullen Scales of Early Learning at 12, 18, and 24 months. Results suggested that (a) parents of high‐ and low‐risk infants produced similar word tokens, word types, and proportions of contingent verbal responses, but parents of high‐risk infants used shorter mean length of utterances (MLU) than parents of low‐risk infants at 18 and 24 months; (b) parents' MLU at 18 months was positively associated with their infants' language at the subsequent visit after 6 months, regardless of group; and (c) infants' language at 18 months was positively associated with parents' MLU at the subsequent visit after 6 months in the high‐risk group only. These findings contribute to our understanding of the mechanisms underlying early language learning of high‐risk infants who have an increased risk for language delays and deficits. Autism Res 2020, 13: 1168‐1183. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryParents provide an important source of language input to their children. In this study, we looked at parent input to infants at high‐ and low‐risk for autism spectrum disorder and relations between parent input and child language in the first 2 years of life. We found that parents of high‐ and low‐risk infants provided similar quantity and quality of input, except shorter average length of utterances at 18 and 24 months in the high‐risk group. Also, there were bidirectional relations between parent input and child language at 18 and 24 months in high‐risk pairs, suggesting that parents and children collectively shape the early language environment.

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