Developmental care for promoting development and preventing morbidity in preterm infants

Preterm infants experience a range of morbidity related to the immaturity of their organ systems and to concurrent disease states. There is concern that an unfavourable environment in the neonatal intensive care unit (NICU) may compound this morbidity. Modification of the environment could minimize the iatrogenic effects. Developmental care is a broad category of interventions designed to minimize the stress of the NICU environment. These interventions may include elements such as control of external stimuli (vestibular, auditory, visual, tactile), clustering of nursery care activities, and positioning or swaddling of the preterm infant. Individual strategies have also been combined to form programs, such as the 'Newborn Individualized Developmental Care and Assessment Program' (NIDCAP) (Als 1986).

In preterm infants, do developmental care interventions reduce neurodevelopmental delay, poor weight gain, length of hospital stay, length of mechanical ventilation, physiological stress and other clinically relevant adverse outcomes?

The Neonatal Review Group search strategy was utilized. Searches were made of MEDLINE from 1966 to June, 2005 and of CINAHL, The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2005), and conference and symposia proceedings in the English language from 1990 to June, 2005. A search of EMBASE was also made from 2003 to June 2005. A list of all relevant articles was sent to two experts in the field to identify any omissions or additional unpublished studies.

Randomized trials in which elements of developmental care are compared to routine nursery care for infants < 37 weeks gestation and that measured clinically relevant outcomes. Reports were in English or a language for which a translator was available. Computerized searches were conducted and all potentially relevant titles and abstracts were extracted. Retrieved articles were assessed for relevance independently by two reviewers, based on predetermined criteria. Articles that met all criteria for relevance were assessed for methodological quality based on predetermined criteria. Articles judged to have the appropriate quality by both reviewers were included in the analysis.

Data were extracted independently by the two authors. Meta-analyses were conducted for each intervention where the same outcome measures and/or instruments were used within comparable time points.

This review detected 36 eligible randomized controlled trials involving four major groups of developmental care interventions, 19 sub-groups and multiple clinical outcomes. In addition, the long-term outcomes of a previously included trial were added to the review. The results of the review indicate that developmental care interventions demonstrate limited benefit to preterm infants with respect to: decreased moderate-severe chronic lung disease, decreased incidence of necrotizing enterocolitis and improved family outcome. Conversely, an increase in mild lung disease and an increase in the length of stay were demonstrated in infants receiving developmental care compared to controls. There is also very limited evidence of the long-term positive effect of NIDCAP on behavior and movement at 5 years corrected age but no effect on cognition. Other individualized developmental care interventions have also demonstrated some effect in enhancing neurodevelopmental outcome. Although a limited number of other benefits were demonstrated, those results were from single studies with small sample sizes. The lack of blinding of the assessors was a significant methodological flaw in half of the studies. The cost of the interventions and personnel was not considered in any of the studies.

Because of the inclusion of multiple interventions in most studies, the determination of the effect of any single intervention is difficult. Although there is evidence of limited benefit of developmental care interventions overall, and no major harmful effects reported, there were a large number of outcomes for which no or conflicting effects were demonstrated. The single trials that did show a significant effect of an intervention on a major clinical outcome were based on small sample sizes, and the findings were often not supported in other small trials. Before a clear direction for practice can be supported, evidence demonstrating more consistent effects of developmental care interventions on important short- and long-term clinical outcomes is needed. The economic impact of the implementation and maintenance of developmental care practices should be considered by individual institutions.