To investigate changes in nutritive sucking patterns, behavioral state, and neurobehavioral development of preterm infants from the 34 weeks postconceptional age (PCA) to term.
Nonexperimental descriptive correlational design was used.
A convenience sample included 66 preterm infants with a gestational age between 24 and 34 weeks at birth. Mean gestational age was 29.7 weeks, with a mean birthweight of 1379 grams. Instruments included the Kron Nutritive Sucking Apparatus, the Anderson Behavioral State Scale (ABSS), and the Brazelton Neonatal Behavioral Assessment Scale (BNBAS). A feeding procedure was administered at 34 and 40 weeks PCA with BNBAS administered at 40 weeks PCA. Data analysis strategies included t-tests, Spearman rho correlations, Wilcoxon matched-pairs signed-ranks test, and a Random Coefficients Model.
There were significant differences in number of sucks (p < 0.001), intensity of sucking pressures (p < 0.001), average time between sucks (p < 0.001), and average time between bursts (p < 0.001) from 34 weeks PCA to term. With maturation, it was noted that the preterm infants were significantly more alert during the sucking protocol from 34 weeks to term (p < 0.001). Yet, infant sucking parameters at 34 weeks PCA and term were not significantly related to the BNBAS or to the infant's state.
These results demonstrate that high risk preterm infants mature significantly in their sucking behaviors and in their ability to maintain a more alert behavioral state from 34 weeks PCA to term. However, unlike full term infants-where state is positively correlated to feeding (sucking) success-the preterm infant state of alertness may not enhance sucking skills at 34 weeks PCA. These infants may be too stressed to manage both feeding and stimulation from the environment that is unavoidable when alert. However, this relationship does appear to change by 40 weeks PCA.
Barbara Medoff-Cooper is a Professor at the University of Pennsylvania, School of Nursing, Philadelphia, Pennsylvania. She can be reached at the University of Pennsylvania, School of Nursing, 420 Guardian Drive, Philadelphia, PA 19104-6096; e-mail: firstname.lastname@example.org
Jacqueline M. McGrath is an Assistant Professor at the School of Nursing, Arizona State University, Tempe, Arizona.
Warren Bilker is an Associate Professor at the University of Pennsylvania, School of Medicine, Philadelphia, Pennsylvania.
Supported by NIH, NINR grant #R01NR02093-04A3.