Before answering this question, let’s take a look at how much milk the baby can suck out of the breast. Usually, the baby can eat 67% of the milk in the breast. In other words, there is more milk in the mother’s breast than the baby needs. The baby did not eat all the milk in the breast. So the breast pump is the same. When we use a breast pump instead of a baby to suck out the milk in our breasts, about 67% of the milk can be sucked out. There is no need to pursue complete emptying. Of course, mothers who are chasing milk need to increase this emptying rate, so that the breast can receive the signal to produce more milk. The amount of milk that your breast pump can suck from your breasts varies from person to person and from machine to machine.