Background: Although various methods have been used to objectively evaluate an infant’s sucking behavior during breast- and bottle-feeding, variations in instruments and technologies currently employed make it difficult to compare findings across breast and bottle-feeding conditions. Therefore, we developed a new method, the Infant Sucking Measurement System (ISMS) that provides a consistent assessment of sucking across breast and bottle-feeding. The purpose of this study was to present preliminary findings of the feasibility and validity of the ISMS.
Methods: In Phase 1, we examined the ability of the ISMS to differentiate different levels of negative pressure generated by an artificial sucking condition using a breast pump. In Phase 2, we tested the feasibility and validity of the ISMS with data obtained from four mothers and their healthy full-term infants (two bottle-feedings and two breastfeedings). Intraoral pressures were measured using the ISMS along with a video camera simultaneously recording the infant’s cheek movements. Mothers provided feedback for improvement of the ISMS design. Following each observation, the team reviewed the findings and refined the system; refinements were trialed with the next study. To test the validity of the ISMS, a one-minute period with the highest quality ISMS signal was selected from each feeding to examine the synchrony between ISMS intraoral pressure measurements and coded cheek movements.
Results: The ISMS differential pressures when low, medium, and high suction pressures were applied by a breast pump were 18.8, 29.6, and 40.3 kPa, respectively. The agreement between direct observation of sucking and ISMS data was high (mean: 90.6%, range: 84.6-100%). With a series of modifications, we found that the ISMS was a feasible method of reliably measuring intraoral pressure during breast-feeding; however, further testing is necessary to optimize methods of securing the catheter to the bottle nipple.
Conclusions: Preliminary data support the validity of the ISMS for identifying sucks and quantifying intraoral pressure generated by sucks in both breast and bottle-feeding. Although further modifications are needed to improve the attachment of the device to the bottle nipple, our initial results support further investigation of the ISMS for use in high-risk infants to evaluate sucking behaviors.