Early Expressed Milk Volume and Coming to Volume for Mother’s Own Milk in Hospitalized Infants

Background: Early pumping frequency is strongly correlated with achieving coming to volume (CTV) and having increased milk volume production. A model was created to predict CTV using early pumping frequency, achievement of early morning pumping, and birth weight. Research Aim: To assess if cumulative pumping volumes during the first 5 postnatal days (CV x 5) influence coming to volume (CTV: producing > 500 milliliters breast milk per day by postnatal Day 14) for mothers of hospitalized infants, with a secondary aim to develop and compare a new predictive model using CV x 5 with our previous model. Methods: A retrospective cohort analysis was conducted at a tertiary center for singleton mother–baby dyads of neonatal intensive care infants between January 2020 and December 2023. Results: Of 887 mother–baby dyads, 325 (37%) achieved CTV and were more likely to have higher CV x 5 (1,058 ± 25 ml vs. 231 ± 19 ml; p < 0.0001). In generalized regression models for CTV that included birth weight, five or more milk-producing pumping episodes on postnatal Day 5 (5 x 5), pumping at least once between 1 am and 5 am by postnatal Day 5 (AM x 5), and CV x 5, only CV x 5 and 5 x 5 remained significant ( p < 0.0001). Conclusions: Pumping frequencies and accumulating pumped volumes in the first 5 postnatal days are important factors in predicting mothers’ likelihood of CTV. CTV is significantly associated with CV x 5, and, with 5 x 5, creates a stronger model than that of 5 x 5 and higher birthweight. This new model may help identify mothers needing additional support to achieve CTV as early as postnatal Day 5.