Assessment & Research

Early developmental profiles among infants with Down syndrome.

Onnivello et al. (2023) · Journal of intellectual disability research : JIDR 2023
★ The Verdict

Down syndrome infants already split into three Bayley-III delay levels—use them to set initial therapy intensity.

✓ Read this if BCBAs who assess or treat babies with Down syndrome in early-intervention programs.
✗ Skip if Practitioners who only serve school-age or adult clients.

01Research in Context

01

What this study did

Researchers gave the Bayley-III to 75 babies with Down syndrome. The babies were 4 to 18 months old.

They used latent profile analysis to see if the scores formed clear groups.

02

What they found

Three groups showed up: mild delay, moderate delay, and pronounced delay. Each baby fit one group.

The groups were already visible before the first birthday.

03

How this fits with other research

Fernández-Alcaraz et al. (2020) tested adults with Down syndrome and found a flat profile. Verbal and visual skills stayed together. The baby groups seem to fade by adulthood.

Eggleston et al. (2018) tracked the same HA-ID adults for five years. They showed that heavy medical needs, not early profile, predicted later mortality. Early Bayley group did not map onto later health risk.

Konstantareas et al. (1999) showed the Stanford-Binet IV is reliable in adults. Together, these papers say: use Bayley-III to plan baby therapy, but re-test later because profiles can shift.

04

Why it matters

You can sort babies into mild, moderate, or pronounced delay right after diagnosis. Start speech, OT, and ABA at the dose each group needs. Re-check skills every six months; the flat adult profile tells us these early groups are not life-long labels.

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Run a Bayley-III on your next Down syndrome intake under 18 months and match therapy hours to the mild, moderate, or pronounced profile.

02At a glance

Intervention
not applicable
Design
other
Sample size
75
Population
down syndrome
Finding
not reported

03Original abstract

BACKGROUND: Down syndrome (DS) generally predisposes children to a pattern of relative developmental strengths and challenges, but within-syndrome heterogeneity is also commonly observed across many dimensions. The present research examines whether heterogeneity in developmental presentation can be detected during infancy in DS and whether factors associated with differing profiles can be identified. METHODS: Infants with DS (n = 75; age range: 3.9-17.6 months) were administered the Bayley Scales of Infant Development III (Bayley-III). A primary caregiver provided information regarding developmental history and family demographics. Latent profile analysis was conducted to identify whether early profiles were present across the five Bayley-III domains. RESULTS: Three developmental profiles were observable within the sample: a 'Mild Delay' Profile, an 'Moderate Delay' Profile and a 'Pronounced Delay' Profile. In addition, chronological age, having received heart surgery and having received occupational therapy were associated with probability of profile membership. CONCLUSIONS: Findings from this study contribute to the growing knowledgebase regarding heterogenous presentations associated with DS and can inform early intervention planning.

Journal of intellectual disability research : JIDR, 2023 · doi:10.1111/jir.12997