Developmental Care Does Not Alter Sleep and Development of Premature Infants

Abstract

Objective. The Neonatal Individualized Developmental Care Program (NIDCAP) for very low birth weight (VLBW) preterm infants has been suggested by Als et al to improve several medical outcome variables such as time on ventilator, time to nipple feed, the duration of hospital stay, better behavioral performance on Assessment of Preterm Infants' Behavior (APIB), and improved neurodevelopmental outcomes. We have tested the hypothesis of whether the infants who had received NIDCAP would show advanced sleep-wake pattern, behavioral, and neurodevelopmental outcome. Methods. Thirty-five VLBW infants were randomly assigned to receive NIDCAP or routine infant care. The goals for NIDCAP intervention were to enhance comfort and stability and to reduce stress and agitation for the preterm infants by: a) altering the environment by decreasing excess light and noise in the neonatal intensive care unit (NICU) and by using covers over the incubators and cribs; b) use of positioning aids such as boundary supports, nests, and buntings to promote a balance of flexion and extension postures; c) modification of direct hands-on caregiving to maximize preparation of infants for, tolerance of, and facilitation of recovery from interventions; d) promotion of self-regulatory behaviors such as holding on, grasping, and sucking; e) attention to the readiness for and the ability to take oral feedings; and f) involving parents in the care of their infants as much as possible. The infants' sleep was recorded at 36 weeks postconceptional age (PCA) and at 3 months corrected age (CA) using the Motility Monitoring System (MMS), an automated, nonintrusive procedure for determining sleep state from movement and respiration patterns. Behavioral and developmental outcome was assessed by the Neurobehavioral Assessment of the Preterm Infant (NAPI) at 36 weeks PCA, the APIB at 42 weeks PCA, and by the Bayley Scales of Infant Development (BSID) at 4, 12, and 24 months CA. Results. Sleep developmental measures at 3 months CA showed a clear developmental change compared with 36 weeks PCA. These include: increased amount of quiet sleep, reduced active sleep and indeterminate sleep, decreased arousal, and transitions during sleep. Longest sleep period at night showed a clear developmental effect (increased) when comparing nighttime sleep pattern of infants at 3 months with those at 36 weeks of age. Day-night rhythm of sleep-wake increased significantly from 36 weeks PCA to 3 months CA. However, neither of these sleep developmental changes showed any significant effects of NIDCAP intervention. Although all APIB measures showed better organized behavior in NIDCAP patients, neither NAPI nor Bayley showed any developmental advantages for the intervention group. The neurodevelopmental outcome measured by the Bayley at 4, 12, and 24 months CA showed 64% of the NIDCAP intervention group at the lowest possible score compared with 33% of the control group. These findings could not be explained by the occurrence of intraventricular hemorrhage or the socioeconomic status of the parents, which showed no significant group effect. Conclusion. The results of this study, including measures of sleep maturation and neurodevelopmental outcome up to 2 years of age did not demonstrate that the NIDCAP intervention results in increased maturity or development. Buehler et al (Pediatrics. 1995;96:923–932) have reported that premature infants (N = 12; mean gestational age 32 weeks, mean birth weight 1700 g) who received developmental care compared with a similar group of infants who received routine care showed better organized behavioral performance on an APIB assessment at 42 weeks PCA. None of the medical outcome measures were significantly different in this study. Although our APIB results are in agreement, the results of the NAPI, the Bayley and sleep measures do not show an increase in neurodevelopmental maturation. In the earlier report by Als et al (Journal of the American Medical Association.1994;272:853–858), both medical and neurofunctional improvements were found in very low birth weight premature infants (mean gestational age 27 weeks, mean birth weight ∼870 g) in which 20 infants who received NIDCAP were compared with 18 infants who received routine care. At 42 weeks PCA the APIB was better in the intervention group as was the Bayley at 6 months CA. Later neurodevelopmental assessments in this study population have not been reported. Furthermore, as was indicated in the editorial by Merenstein in the same issue of the Journal of the American Medical Association, a significant problem with the study was that the number of intraventricular hemorrhages was higher in the control group (10 of 18 vs 1 of 20) and the study was conducted before the widespread use of surfactant and prenatal steroids. The study was performed in a single nursery with nurses who volunteered for developmental intervention and cared for the experimental group. No assessment was performed on differences in nursing, intervention, lighting, or sound between the two groups. Apnea, bradycardia, and desaturation data were not reported also. NIDCAP has been shown to reduce stress and agitation in the infants in our study (Heller C, et al. Journal of Perinatology.1997;17:107–112); however, there was no difference in the incidence of apnea or bradycardia. Additional studies are needed to determine which specific interventions facilitate recovery in the high-risk preterm infant when interventions are efficacious, what may be adverse or ineffective, and what mechanisms are involved. Distinctions should be made between medical improvement, neurobehavioral responses (APIB), and neurodevelopmental maturation. Not only the duration of NICU hospitalization, but indeed, long-term outcomes must be carefully evaluated. We recommend that clinicians should be aware that preterm infants who have received NIDCAP during their hospitalization do not appear to be more mature at the time of discharge home.