A Randomized Controlled Trial Comparing the Effect of Duration of Manual Expression and Breastfeeding Self-Efficacy on Milk Volumes in Mothers of Premature Infants: The MERIT Study

Abstract

Premature infants in the neonatal intensive care unit (NICU) are extremely vulnerable, and breast milk is best for the well-being of the infant. Most premature infants, however, are not yet able to suck, so other methods are sought to provide the mother’s milk to the baby. These techniques include manual expression and electric breast pumps; however, little is known about the duration of manual expression to optimize milk volumes. In addition, the measurement of self-efficacy has frequently been explored with breastfeeding mothers and is thought to be an important variable to identify mothers at risk for early discontinuation of breastfeeding. The purpose of this study was to determine how the duration of manual expression affects milk volumes and levels of breastfeeding self-efficacy in mothers of premature infants. Mothers were randomly assigned to either three days or seven days of manual expression prior to electric pump expression and instructed to record milk volumes for 14 days. Self-efficacy scores were measured at baseline and 14 days. Breastfeeding self efficacy increased significantly for all mothers in the study but did not differ by study group; 3-day group (Mean=65.7, SD=20.1) as compared to the 7-day group (mean = 72.3, SD =15.4, p=0.458). Follow-up self-efficacy score did not differ by manual expression between the two groups; 3-day group (Mean=76.5, SDF=14.7) as compared to the 7-day group (Mean=80.3, SD=9.3, p=0.751). Milk volumes did not differ by manual expression at follow-up for the 3-day group (Mean =582.7, SD=331.2) as compared to the 7-day group (Mean=700.0, SD=550.0, p=0.770). Results indicate, though not statistically significant, milk volumes are trending toward a clinically meaningful increase in the 7-day manual expression group. Preliminary finding from this study may add to the evidence for the standard of care for premature mothers providing breast milk to their infants. The study interventions, although directly informed by self-efficacy theory, did not result in significant differences in self-efficacy levels according to study group. If the duration of manual expression can be determined, a standardized approach can be established for mothers of premature infants in order to achieve optimal milk volumes.