Importance of Vacuum for Breastmilk Expression

Abstract

Objective: To determine the effect of the strength of applied vacuum on the flow rate and yield of breastmilk using an electric breast pump. Study Design: Twenty-one breastfeeding mothers and two expressing mothers expressed their breastmilk for 15 minutes using an electric breast pump set at their own maximum comfortable vacuum, and at one to three softer vacuums. Milk yield and flow rate were measured. Results: At the maximum comfortable vacuum (؊190.7 ؎ 8.8 mm Hg) 4.3 ؎ 0.4 milk ejections occurred during 15 minutes of expression and yielded 118.5 ؎ 11.4 mL of milk (65.5 ؎ 4.1% of the available milk). Softer vacuums yielded less milk volume (p Ͻ 0.05) and less of the available milk (p Ͻ 0.01). Milk flow rate was greater during the first milk ejection than the third or subsequent milk ejections (p Ͻ 0.001). Cream content of the milk was highest after expressing for 15 minutes using the mother's maximum comfortable vacuum. Conclusions: Use of the mother's maximum comfortable vacuum enhances milk flow rate and milk yield. The cream content of the milk at the end of the expression period was an indicator of how effectively the breast had been drained.

Combining hand techniques with electric pumping increases milk production in mothers of preterm infants

“…Additionally, the wide range of duration of expression in this study from 15 to 45 min, averaging 25 min, suggests that specifying a time frame for pumping duration for any mother, as mentioned by Kent et al, 38 could negatively impact volume.…”

Simultaneous Breast Expression in Breastfeeding Women Is More Efficacious Than Sequential Breast Expression

“…The breastfeed volumes and cream contents of the milk samples (measured by the creamatocrit method 13 on the Creamatocrit PlusÔ device 14 [Medela Inc., McHenry, IL]) were used to calculate the breastfeeding storage capacity as described previously. 15 Before and after each pumping session the mothers hand-expressed small milk samples (< 1 mL) from the breast being expressed. The cream content of these milk samples and volume of the expressions, combined with the data from the 24-hour period, were used to calculate the potential storage capacity of the breast as described previously, 15 and the cream content of the initial milk sample was used to calculate the degree of fullness of the breast at the beginning of the pumping session.…”

“…15 Before and after each pumping session the mothers hand-expressed small milk samples (< 1 mL) from the breast being expressed. The cream content of these milk samples and volume of the expressions, combined with the data from the 24-hour period, were used to calculate the potential storage capacity of the breast as described previously, 15 and the cream content of the initial milk sample was used to calculate the degree of fullness of the breast at the beginning of the pumping session. 15 Multiplication of the degree of fullness by the potential storage capacity gave the amount of milk available in the breast before the experimental expression sessions.…”

“…The cream content of these milk samples and volume of the expressions, combined with the data from the 24-hour period, were used to calculate the potential storage capacity of the breast as described previously, 15 and the cream content of the initial milk sample was used to calculate the degree of fullness of the breast at the beginning of the pumping session. 15 Multiplication of the degree of fullness by the potential storage capacity gave the amount of milk available in the breast before the experimental expression sessions. 15 The amount of milk expressed as a percentage of the amount of milk available gave a measure of the efficacy of the expression session.…”

“…15 Multiplication of the degree of fullness by the potential storage capacity gave the amount of milk available in the breast before the experimental expression sessions. 15 The amount of milk expressed as a percentage of the amount of milk available gave a measure of the efficacy of the expression session.…”