A Cohort Study on Comparison of Volumes of Breast-Pump-Expressed Human Milk Donor Among Term and Preterm Gestational Mothers in South India––Time to Redefine “Coming to Volume” in the Milk Bank?

Introduction: Human milk banking is an essential perinatal service. The present study evaluates the impact of gestational age on the volumes of milk. Further, it also re-evaluates the definition of “Coming to Volume” in pump-based expression of milk. Methodology: This cohort study was conducted at a tertiary care centre in south India over 10 months from September 2022 to June 2023. The primary objective of the study was to compare the volume of donor milk secreted in relation to postnatal day among mothers delivered at term and preterm gestation. The secondary objective of the study was to compare the definition of “Coming to Volume” (secretion of 500 mL per day by postnatal day 14) with the volumes of milk in the present study. A surrogate marker for “Coming to Volume”, that is, an expression of at least 80 mL in one sitting of the donation was considered. Results: Of the total 458 mothers, there were 349 (Term) and 109 (preterm) mothers. The average volumes of donor human milk were 142 mL and 122 mL among term and preterm mothers, respectively ( p-value .0068). Further, 80% of the term mothers and 75% of the preterm mothers were able to secrete>80 mL per sitting. This volume was attained by postnatal day 7 in 80% (223/280) of term mothers and 65% (53/82) of preterm mothers.