Table 5.
Motor functioning
| Study | Age at different assessments (in months) | Total number of participants | Number of EL siblings | Number of siblings with ASD outcome | Number of siblings with TD outcome | Number of siblings with another outcomea | Topic | Assessment method | Diagnostic instruments | Difference EL-ASD vs EL-TD and/or predicts ASD diagnosis | Main findings |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Brian et al. (2008) Canada [46] | 6–12, 18, 36 | 228 | 155 | 35 | 120 | Motor control, general motor behaviour | ADOS-G, AOSI | ADOS-G, ADI-R, expert clinical judgment according to DSM-IV-TR | Yes |
At time 1 (6-12 m): no motor impairment was identified in any participant At time 2 (18 m): EL-ASD showed atypical motor behaviour compared to EL-TD and to TL and abnormal motor control compared to TL Motor control predicted, with other dimensions, ASD at 36 m |
|
| Choi et al. (2018) US [48] | 6, 12, 18, 24, 36 | 170 | 101 | 30 | 71 | - | Fine motor milestones | MSEL | ADOS-G | Yes |
At 12 m no difference between EL-ASD, EL-TD and TL EL-ASD had lower fine motor skills than EL-TD at 12 m and than TL at 18 m EL-ASD had lower growth rate than TL but not compared to EL-TD from 6 to 24 m |
| Estes et al. (2015) US [26] | 6, 12, 24 | 308 | 210 | 31 | 161 | 18 | Fine and gross motor milestones | MSEL | ADOS, ADI-R, expert clinical judgment | No |
At 6 m EL-Autism had lower gross motor scores than TL At 24 m EL-Autism had lower scores in both Gross and Fine motor scales than EL-TD and TL. EL-ASD had lower scores in Fine motor scale than TL |
| Kaur et al. (2015) US [43] | 6, 9, 12, 15, 18, 24 | 32 | 16 (2 preterm) | 3 (2 preterm) | 8 | 5 | Fine motor milestones (grasping, dropping, mouthing) | Infants seated in a booster seat. Objects presented: a rattle, a koosh ball, a rigid ball | ASQ-3, M-CHAT, follow-up inquiries with parents | No |
Grasping: EL showed less grasping of the rigid ball at 6 m than TL. Between 6 and 9 m TL had reduced grasping of the rigid ball; EL had increased grasping of the rigid ball and rattle. Between 9 and 12 m TL increased grasping of the rattle and EL increased grasping of the koosh ball Dropping: EL at 6 m showed much less dropping of the rigid ball, more dropping of objects from 6 to 9 m but lower level of dropping from 12 to 15 m compared to TL. TL showed increased dropping of objects from 6 to 9 m, while EL had delayed increase in dropping from 12 to 15 m Mouthing: EL showed less mouthing of the rattle at 6 m and more mouthing of the rattle and rigid ball at 15 m compared to TL |
| Iverson et al. (2019) US [63] | 6, 36 | 625 | 437 | 69 | 317 | 51 | Fine and gross motor milestones | MSEL | ADOS, expert clinical judgment according to DSM-IV-TR | Yes | Fine motor but not gross motor scores at 6 m predicted ASD at 36 m |
| Landa et al. (2006) US [47] | 6, 14, 24 | 87 | 87 | 24 | 52 | 11 | Fine and gross motor milestones | MSEL | ADOS-G, expert clinical judgment according to DSM-IV | Yes |
At 14 m EL-ASD had a lower score than EL-TD in Gross motor and Fine motor scales EL-ASD showed a lower increase over time than EL-TD |
| Landa et al. (2012) US [41] | 6, 14, 18, 24, 30, 36 | 204 | 204 | 52 | 121 | 31 | Fine and gross motor milestones | MSEL | ADOS-G, expert clinical judgment | Yes |
EL-ASD were more likely assigned to the developmental slowing class (typical functioning at 6 m followed by attenuation in developmental rate and severe delay in fine and gross motor development) compared to EL-TD EL-Other (BAP) were assigned to normative class or language/motor delay class (fine motor delay at 6 m followed by normative development in all areas except in gross and fine motor development) |
| LeBarton et al. (2019) US [64] | 6, 24, 30, 36 | 140 | 89 | 20 | 69 | – | Fine (visual-motor integration, grasping) and gross (stationary) motor milestones | Peabody Developmental Motor Scales – 2 (PDMS2) | ADOS-G | Yes |
At 6 m EL-ASD showed worse visual-motor integration than TL; no significant between-group difference at 6 m in stationary and grasping was found Visual-motor integration at 6 m predicted ASD at 24–36 m |
| Libertus et al. (2014) US [42] | 6, 36 | 129 | 107 | 22 | 57 | 28 | Fine and gross motor milestones | MSEL | ADOS-G, expert clinical judgment according to DSM-IV | No |
At 6 m: for gross motor development, no between-group difference was found for fine motor development, significantly higher scores in TL than EL-TD, EL-Other and EL-ASD were found. Post-hoc comparison showed no differences between the 3 EL subgroups |
| Nickel et al. (2013) US [27] | 6, 9, 12, 14, 18, 21, 24, 36 | 40 | 22 | 4 (EL-Autism) | 18 | – | Posture | Home videos videotaped and coded | ADOS-G, expert clinical judgment according to DSM-IV | Yes | From 6 to 12 m EL-Autism were seen in half as many different postures as EL-TD and TL (positions at 6 m: prone, supine, sit supported, sit unsupported, all-4) but by 14 m differences were no longer visible |
| Sacrey et al. (2018) Canada [49] | 6, 9, 12, 15, 18, 24, 3 | 30 | 10 | 10 | 10 | – | Fine and gross motor milestones: reach-to-grasp movement (orient, lift, pronate, grasp) | Videos during AOSI, ADOS-G, videotaped and scored using the Skilled Reaching Rating Scale | ADOS-G, ADI-R, expert clinical blind assessment according to DSM-IV-TR | Yes |
EL-ASD had worse reach-to-grasp scores than EL-TD and TL (which did not differ); no group × age interaction was found EL-ASD showed: worse orient and lift than TL but did not differ from EL-TD worse pronate scores than EL-TD and TL no difference in grasp from any other group Improvement in orienting started between 9 and 12 m and in lifting and pronate from 6 m |
aAtypical outcome: deficit in general cognition, motor functioning, language delay, Broader Autism Phenotype (BAP, social communication delay)