Beyond Traditional Milestones: Questioning Developmental Framework for Children With Down Syndrome

The study of Baumer et al1 on developmental milestones for children with Down syndrome (DS) raises several issues to which we would like to draw attention.The study attempts to establish condition-specific developmental benchmarks for children with DS, reinforcing outdated stereotypes and perpetuating the myth that development follows a predictable, linear path. This approach may mislead clinicians and families by suggesting that the developmental trajectories of children with DS can be assessed using the same standards as those for neurotypical children.The developmental milestones of Baumer et al (eg, walking and talking) reinforce an ableist perspective, reducing development to a checklist of tasks within a specific timeframe. This view does not capture the nuances and complexity of any child’s development.2 Each child’s journey is unique, and their development must be understood within their broader environment and interactions. As illustrated by the World Health Organization’s International Classification of Functioning, Disability and Health, known as the ICF Framework,3 a strengths-based view that emphasizes functionality over arbitrary milestones offers a more holistic understanding. Development must be seen as a dynamic process, requiring individualized support and a focus on functional engagement rather than strict milestone attainment.By framing certain delays as “typical,” such as the expectation that children with DS should achieve 2-word phrases by age 7 years, the study risks fostering clinical complacency. This thinking misses the capacity for “communication” by alternate means and risks preventing clinicians from pursuing early interventions crucial to addressing co-occurring conditions, such as language or sensory impairments. Normalizing delays easily leads to missed opportunities for developmental support.Development is not solely a biological process, it is deeply influenced by social, educational, and environmental factors, including the quality of children’s care, therapy, and education. Baumer et al fail to account for these critical influences, overlooking how every child’s broader context affects their progress. As Bull’s (2024) commentary highlights, there is still much work to be done to fully understand the diverse developmental trajectories of children with DS. This includes addressing comorbidities and acknowledging the essential role of caregivers in promoting developmental skills.4The Lancet viewpoint raises ethical concerns about the standardization of developmental norms in a population as varied as children with DS.5 Overreliance on milestone-based standards risks creating a deficit-based view of development, focusing on what children “cannot do” rather than celebrating their strengths. This approach may limit opportunities for children with DS to engage fully with their environment and reach their potential.In conclusion, the promotion of milestones by Baumer et al perpetuates the myth of “normal” development and risks reinforcing harmful stereotypes about children with DS. The study takes an unintended step backward by reinforcing outdated medical thinking that views developmental delays as inherent deficits. By focusing on a milestones-based approach, it misses opportunities to identify meaningful research directions that could improve the quality of life for these children and their families. Instead, a holistic, strengths-based approach that emphasizes early intervention and social context would better support the full potential of children with DS, embracing the diversity of their abilities.