A breast pump has at least one collection assembly for engaging at least a portion of a breast surrounding a nipple and a vacuum pump for applying a vacuum to the collection assembly and thereby to at least the nipple of the breast. A controller is operable to cyclically operate the vacuum pump between a maximum vacuum pressure in the range of about 70 mm Hg to about 150 mm Hg and a latching pressure of about 30 mm Hg.