Breast Milk Production Variability Among Mothers of Preterm Infants

Introduction: Mothers of preterm infants are at risk for inadequate milk production. Pumping logs are often used to both encourage lactation in the first week and track its efficacy. Our objectives were to determine whether mothers of preterm infants who keep pumping logs are demographically different from those who do not and to determine whether this practice affects the amount of mother's own milk (MOM) fed to their infants. We also aimed at determining whether there is a correlation between: (1) time to first breast milk expression, (2) cumulative frequency of expression in the first week, and (3) milk volume on day 7 with subsequent milk volumes and percent of infant diet consisting of MOM. Methods: Mothers of infants born ≤32 weeks and ≤1,500 g were enrolled within 48 hours of birth and encouraged to keep a pumping log. Data were collected on maternal characteristics, patterns of milk expression, and milk volumes on days 7, 14, 21, and 28 after delivery. Infant data were collected via chart review. Results: Mothers who kept pumping logs provided their own milk for a greater percentage of their infant's feeds at the time of achieving full feeds (p = 0.017). The total number of expressions in the first week was correlated with milk volume on day 21 (p = 0.016) and the provision of a higher percentage of MOM feeds at discharge (p = 0.03). Milk volume on day 7 correlated with volumes obtained at days 14, 21, and 28 (p < 0.001). Conclusions: Pumping logs may affect the availability of MOM for preterm infants. Frequency of pumping in the first week and milk volume on day 7 may impact long-term lactation success for these women.