Comparison of milk output between breasts in pump-dependent mothers.

This article reports the naturally occurring pattern of milk output beginning day 6 through day 42 postpartum from each individual breast in 95 pump-dependent mothers of a non-nursing preterm infant. Of the 3488 study days, milk output was greater from the left breast on 51.6% (n = 1800) of the study days, from the right breast 45.8% (n = 1598) of the study days, and equal 2.6% (n = 90) of the study days. Overall, total left and right breast milk output for the entire study (37 days) was 52.6% and 47.4%, respectively. There was no significant relationship between individual breast milk output and maternal handedness, parity, or breastfeeding experience. Clinicians need to assess the total milk output as well as individual breast output in lactating mothers, as there may be significant disparities in milk production.