Highlights of the Study
Long-term Efficacy
Children who received the Enhanced Developmental Intervention (EDI) showed significantly higher median scores in executive function domains compared to those receiving usual care at a 7-year follow-up.
Parent-Led Success
The study underscores the efficacy of training parents as primary agents of developmental support, starting from the neonatal intensive care unit (NICU) through the first two years of life.
Broad Impact
Improvements were observed across multiple domains, including auditory attention, inhibition, design fluency, and motor persistence, with medium to large effect sizes reported.
Scalability
Conducted in a low-to-middle-income setting, the results suggest that EDI models are both feasible and effective in diverse socioeconomic environments.
The Cognitive Vulnerability of Very Preterm Infants
Children born very preterm (VPT; <32 weeks' gestation) or with very low birth weight (VLBW; <1500 g) face a heightened risk of neurodevelopmental impairments. Among the most pervasive challenges are deficits in executive function (EF). Often described as the brain's 'CEO,' executive function encompasses a suite of top-down mental processes—including working memory, inhibitory control, and cognitive flexibility—necessary for goal-directed behavior, social-emotional regulation, and academic success.
The vulnerability of these functions in VPT children is linked to the disruption of critical periods of brain development, particularly white matter connectivity and the maturation of the prefrontal cortex. While early childhood interventions have long been utilized to support motor and cognitive development, their long-term impact on the more complex, higher-order executive functions at school age has remained a subject of clinical debate. There is a pressing need for evidence-based interventions that can be initiated early and sustained over time to bridge the developmental gap.
Study Design and Methodological Rigor
This study was a secondary analysis of a randomized clinical trial (RCT) conducted at a single center in Porto Alegre, Brazil. The trial enrolled infants born at fewer than 32 weeks of gestation or with a birth weight below 1500 g between 2016 and 2019.
The Intervention: EDI vs. Usual Care
The Enhanced Developmental Intervention (EDI) was designed as a parent-led program. It began in the NICU, focusing on sensitive caregiving and environmental stimulation, and continued at home through the first two years of the child’s life. In contrast, the control group received ‘usual care,’ which consisted of standard pediatric follow-up and neonatal care without the structured, parent-led developmental coaching.
Assessment and Endpoints
Follow-up assessments were conducted between July 2023 and August 2024, when the children reached a mean age of seven years. The primary outcomes were measured using the Developmental Neuropsychological Assessment, Second Edition (NEPSY-II), a gold-standard tool for evaluating neuropsychological development in children. Specifically, the researchers focused on subtests for:
1. Auditory Attention
2. Inhibition
3. Design Fluency
4. Motor Persistence
To ensure objectivity, the examiners were masked to the original group allocation. The researchers employed the Mann-Whitney U test to compare median scaled scores and binary logistic regression to evaluate performance classifications, applying a Bonferroni correction to maintain statistical stringency.
Analyzing the Results: Significant Gains in Executive Function
The analysis included 80 children, representing 96% of the original eligible cohort, highlighting an impressive retention rate for a long-term follow-up study. The demographic and baseline clinical characteristics were well-balanced between the EDI and usual care groups.
Quantitative Improvements
The results were striking. In the primary analysis of median scaled scores, children in the EDI group outperformed their counterparts in the usual care group across every domain assessed:
– Auditory Attention and Inhibition: Median scores reached 12–14 in the EDI group compared to 2–9 in the usual care group.
– Effect Sizes: The rank-biserial correlation (r) ranged from 0.44 to 0.77, indicating medium to large effect sizes.
– Statistical Significance: All primary comparisons remained significant (P < .001) even after the rigorous Bonferroni correction (P < .0125).
Performance Classification
When evaluating the odds of achieving ‘expected’ performance levels, the EDI group showed a particularly strong advantage in design fluency. The odds ratio (OR) was 11.3 (95% CI, 4.08-31.7; P < .001), suggesting that the intervention vastly increased the likelihood of a child reaching age-appropriate milestones in non-verbal problem-solving and creativity. While the other three domains also trended toward better performance in the EDI group, the binary performance classification did not reach statistical significance, likely due to the high sensitivity of the median score analysis compared to categorical thresholds.
Expert Commentary and Clinical Implications
The findings from this trial provide robust evidence for the ‘first 1000 days’ theory of neurodevelopment. By engaging parents early—starting in the high-stress environment of the NICU—the EDI model leverages the primary caregiver’s role as a constant developmental catalyst.
Mechanistic Insights
Why does early parent-led intervention have such a lasting effect? Experts suggest that EDI likely fosters ‘serve-and-return’ interactions, which are essential for building neural pathways. By teaching parents how to interpret infant cues and provide appropriate stimulation, the intervention may mitigate the toxic stress associated with premature birth and NICU stays, thereby protecting the developing prefrontal circuits.
Socioeconomic Considerations
A critical takeaway from this study is its setting in Brazil. Many high-intensity developmental programs are resource-heavy and difficult to implement in low- and middle-income countries (LMICs). The success of a parent-led model in Porto Alegre demonstrates that empowering families with coaching and guidance can be a cost-effective strategy to improve long-term outcomes for preterm infants globally.
Study Limitations
Despite the positive results, the researchers acknowledge certain limitations. As a secondary analysis, the study may not have been originally powered for these specific school-age neuropsychological endpoints. Furthermore, the single-center design may limit the generalizability of the results to different healthcare systems. However, the high follow-up rate and the use of standardized NEPSY-II assessments lend significant weight to the findings.
Conclusion and Future Directions
The study by Tarouco et al. confirms that the benefits of early developmental intervention extend far beyond the toddler years. For children born very preterm, the EDI model offers a pathway toward improved executive function, which is a critical predictor of future academic achievement and social integration.
Clinicians should consider these findings when designing post-discharge care for preterm infants. Moving toward a model that prioritizes parent training and long-term developmental support could significantly alter the life trajectory of this vulnerable population. Future research should focus on multi-center trials and exploring whether these EF gains translate into better school performance and lower rates of ADHD or other behavioral disorders in adolescence.
Funding and Registration
This research was registered at ClinicalTrials.gov with the identifier NCT02835612. The study was supported by regional health research funding agencies in Brazil.
References
1. Tarouco ML, Procianoy RS, O’Shea TM, Silveira RC. Parent-Led Early Intervention in Very Preterm Infants and Executive Function at School Age: Secondary Analysis of a Randomized Clinical Trial. JAMA Pediatr. Published online January 20, 2026. doi:10.1001/jamapediatrics.2025.5866.
2. Anderson PJ. Neuropsychological outcomes of children born very preterm. Semin Fetal Neonatal Med. 2014;19(2):90-96.
3. Spittle AJ, Orton J, Anderson PJ, Boyd R, Doyle LW. Early developmental intervention programmes provided post-discharge from hospital for preventing motor and cognitive impairment in preterm infants. Cochrane Database Syst Rev. 2015;(11):CD005495.
