Measuring human milk intake in preterm infants: Correlation of the Preterm Infant Breastfeeding Behavior Scale (PIBBS) and test weighing

The development of a noninvasive observational instrument that assesses the breastfeeding behaviors of the preterm infant and correlates with milk intake is a desired research and clinical goal. Current breastfeeding assessment instruments evaluate feeding efficiency by observing a group of maternal and infant breastfeeding behaviors. Test weighing evaluates milk intake but does not provide information on the infant\u27s breastfeeding behaviors. A comparison of the scores obtained on the PIBBS against test weights was performed to determine if the PIBBS could predict milk intake in the preterm infant. A convenience sample of 50 breastfeeding mother-preterm infant dyads were studied during a single breastfeeding session using a cross-sectional design. After establishing interrater reliability between the investigator and two lactation specialists, sessions were observed simultaneously by the investigator and one lactation specialist using the PIBBS. At the conclusion of the breastfeeding session the investigator, lactation specialist and the mother rated the session using the PIBBS. The investigator weighed each infant before and after the breastfeeding session using an integrated, electronic infant scale. Interrater agreement between the investigator and trained lactation specialists averaged substantial chance-corrected agreement (kappa = 0.73, p = .01). Agreement between the mothers and the investigator and the individual lactation specialists ranged from chance to slight chance-corrected agreement (kappa mean = 0.14). Therefore, this study demonstrated that the PIBBS, when used by trained lactation specialists, is a reliable instrument for evaluating preterm infants\u27 breastfeeding behaviors. The correlation between the investigator\u27s PIBBS scores and the infants\u27 milk intake was statistically significant but the magnitude of the correlation was low (r = 0.48, p = .01). In a hierarchical regression analysis the PIBBS score was the only statistically significant predictor after infant\u27s post menstrual age (PMA) and breastfeeding experience (BFE) were controlled and explained approximately 20% of the variance in the volume of milk intake. In conclusion, the PIBBS is not a valid instrument to predict the volume of milk intake consumed by the preterm infant during breastfeeding