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.
Table of Contents
Introduction -- Review of the literature -- Theoretical framework and methodology -- Results -- Discussion -- Appendix A. Institutional Approval Letter -- Appendix B. Breastfeeding Mothers’ Demographic Data -- Appendix C. Breastfeeding Self-Efficacy Scale for Mothers of Ill and/or Premature Infants (BSES-SF) -- Appendix D. BSES-SF Permission from Author -- Appendix E. Breastfeeding Mothers’ Pumping Diary Log - Experimental Group -- Appendix F. Breastfeeding Mothers’ Pumping Diary Log - Control Group -- Appendix G. St. Louis Children’s Hospital (SLCH) Guide to Breast Pumping: How to use the Ameda Platinum ® Breast Pump the First 3 days Appendix H. UMKC IRB Approval Letter -- Appendix I. UMKC Approved Informed Consent Form -- Appendix J. Making Enough Milk: The Key to Successful Breastfeeding Planning for Day One -- Appendix K. Study Protocol -- Appendix L. SLCH Research Grant Award Letter
Degree
Ph.D.