The World Health Organization defines preterm infants (PTIs) as those born before 37 weeks of gestation [1]. Preterm birth is associated with an increased risk of adverse neurodevelopmental outcomes, including impairments in motor, cognitive, language, and behavioral domains that may persist into adolescence and adulthood, affecting academic performance, mental health, and functional outcomes [2-5]. Early identification of developmental delays and timely intervention are essential to mitigate these risks and promote optimal developmental trajectories.

Early intervention programs, including sensorimotor stimulation and family-centered care, have been shown to improve outcomes in PTIs, particularly when initiated during critical periods of brain development [6,7]. However, in low- and middle-income settings, access to such services remains limited. In Brazil, especially in the northeastern region, structural challenges such as limited health care resources, shortage of trained professionals, and poor integration of care networks often result in delayed or absent developmental follow-up [8-10]. Previous studies conducted in this context have highlighted important gaps in care. Analyses of health system data have shown that a small proportion of PTIs receive early stimulation services during the first year of life (previous unpublished analyses conducted by our group; Multimedia Appendix 1). Additionally, low adherence to postdischarge follow-up (previous unpublished analyses conducted by our group; Multimedia Appendix 1) and limited family understanding of prematurity and neurodevelopment have been reported [11], suggesting barriers to continuity of care and early intervention. Together, these findings indicate a potential gap between hospital discharge and access to developmental monitoring and support.

Despite the recognized importance of early monitoring, there is limited evidence on the feasibility of conducting longitudinal developmental assessments of PTIs in resource-limited settings. Understanding the practical challenges of recruitment, retention, and assessment implementation is essential for designing larger studies and effective intervention programs. Therefore, this study aimed to evaluate the feasibility of recruiting, retention, and longitudinal developmental assessment of PTIs from hospitalization to 3 months of corrected age (CA) in a resource-limited setting in Northeastern Brazil as well as to generate preliminary data on early neurodevelopmental outcomes.

This feasibility study evaluated the recruitment, retention, and implementation of longitudinal developmental assessments in PTIs in a resource-limited setting in Northeastern Brazil. The findings demonstrated moderate recruitment rates, high acceptability of study procedures among retained participants, and substantial challenges in retention and completeness of assessments over time. Additionally, preliminary developmental results suggested a decline in motor performance after hospital discharge and a high proportion of infants at risk for neurodevelopmental impairment.

The moderate recruitment rate observed in this study is consistent with previous feasibility studies involving PTIs in similar contexts. Recruitment in neonatal populations is often influenced by parental stress, clinical instability of infants, and logistical constraints during hospitalization [18]. Additionally, in this study, participant invitation occurred within the first week of the infant’s life, a period characterized by heightened emotional vulnerability among mothers following preterm birth. This early postpartum phase is frequently associated with increased levels of stress, anxiety, and psychological distress, which may negatively impact decision-making and willingness to participate in research [19].

However, the most critical feasibility challenge identified in this study was the high attrition rate after hospital discharge, which reflects a well-documented barrier in longitudinal follow-up programs for PTIs [20]. In this study, 40% of the follow-up losses were due to participant withdrawal and loss of contact. This may be partially explained by the geographical characteristics of the study setting, as the referral maternity hospital serves a large territorial area of approximately 3565 km² across 15 municipalities. Greater distance between participants’ residences and health care facilities has been consistently associated with reduced adherence to follow-up and continuity of care, particularly in vulnerable populations, due to transportation difficulties, costs, and access barriers [21]. In addition, recent evidence highlights that maintaining participation in follow-up programs is particularly challenging in low- and middle-income countries due to socioeconomic factors, transportation barriers, and limited integration of post-discharge care services [22]. A recent feasibility study conducted in Brazil using a hybrid (telehealth and in-person) follow-up model reported higher retention rates and improved adherence, suggesting that alternative follow-up strategies may mitigate these challenges [23]. Similarly, digital and web-based follow-up tools have been proposed as feasible solutions to improve continuity of care and parental engagement in early developmental monitoring [24]. The use of such health technologies may represent a promising and effective alternative for monitoring PTIs in this context, particularly by reducing geographic and logistical barriers to follow-up. In Brazil, data from the TIC Domicílios 2024 report indicate that a substantial proportion of the population, including those in more socioeconomically vulnerable regions, access the internet primarily through mobile phones, which may facilitate the implementation of digital health strategies for follow-up and monitoring [25].

In contrast to retention, acceptability of the study procedures was high among participants who remained in the study, as all caregiver-infant dyads attended follow-up visits and agreed to participate in the assessments. This finding aligns with previous research demonstrating high parental satisfaction and engagement in structured developmental follow-up, including remote or video-based assessments [26]. These results suggest that, once barriers to access are overcome, caregivers are willing to engage in early developmental monitoring. Additionally, a study conducted in the same region reported that caregivers of PTIs have a limited understanding of prematurity and its associated neurodevelopmental outcomes [11]. This suggests that investing in strategies to improve caregiver knowledge, particularly during hospitalization, may further enhance acceptability and engagement in developmental monitoring programs.

The reduced completeness of assessments observed in this study, partially due to infant illness, highlights the clinical vulnerability of this population. PTIs are at increased risk of medical complications and rehospitalization, which can interfere with scheduled follow-up and data collection [5]. This challenge has also been reported in longitudinal studies of PTI, where health instability contributes to missing data and follow-up discontinuity [20].

Regarding developmental outcomes, the observed decline in motor performance between hospital discharge and 3 months of CA is clinically relevant. Early developmental care and continuous monitoring are essential to identify and address emerging delays. In Brazil, referral to early intervention and rehabilitation services for high-risk infants often occurs after the recommended screening window for early neurodevelopmental milestones (4 months of CA) due to systemic barriers in the integration of care networks, creating a gap in stimulation during the critical period of rapid neurological development [27-29]. Recent reviews emphasize that structured follow-up programs with early detection and intervention can significantly improve neurodevelopmental outcomes in PTIs [7]. The absence of postdischarge rehabilitation in this study population may have contributed to the observed decline, reinforcing the importance of continuity of care after hospital discharge.

Taken together, these findings suggest that the main barriers to feasibility in this context are not related to the acceptability of the procedures themselves but rather to external and contextual factors affecting follow-up continuity. This distinction is critical for the design of future studies and interventions. This study has several limitations that should be considered. First, the small sample size and the reduced number of participants completing follow-up (n=10, with only 8 completing all assessments) limit the generalizability of the findings and preclude inferential statistical analysis. Second, the high attrition rate may have introduced selection bias, as participants who completed follow-up may differ systematically from those lost to follow-up. Third, the study was conducted in a single center, which may limit the applicability of the findings to other settings. Although telehealth strategies were identified as promising approaches to improve retention, they were not implemented in this study due to resource and infrastructure limitations at the time of data collection. Future studies should consider incorporating hybrid or remote monitoring strategies to enhance feasibility.

This study demonstrates that the longitudinal developmental monitoring of PTIs in a resource-limited setting is feasible, with moderate recruitment and high acceptability of procedures. However, significant challenges related to retention and completeness of assessments were identified, particularly after hospital discharge. These findings highlight the need for strategies to improve follow-up continuity, such as alternative care models and strengthened postdischarge support. Future larger-scale studies are warranted to evaluate the effectiveness of such strategies and to further investigate early developmental outcomes in this population.