How to use a breast pump

Investing in a breast pump can be a big decision, and it really depends on your needs. Electric models automate the process but are pricey; a double one lets you minimize the time you spend expressing and is best for those who pump often or exclusively. If you’re an occasional pumper, you might get by with a manual version, on which you squeeze a lever to create suction. This can get tiring, but the manual pumps are less expensive. The pump shown here is the Medela Freestyle Double Electric Breast Pump, the market leader and most popular double electric pump. 

Hover over the numbers to see how each part functions.

1. The part that looks like a funnel is officially called a breast shield or flange (this is different from a nipple shield). They come in a standard 24-millimetre size that fits around the nipples of approximately 70 percent of women. If your nipples are smaller or larger—do not include your areola in your measurements—you might need to try another size. (Breast shields range from 21 to 37 millimitres if you special-order or go to a maternity store—some even have samples you can try on.) Because bodily fluids touch them, the shields (along with the bottles and any part that comes in contact with your breasts or milk) need to be cleaned after every use.  

2. Air flows through the tubes and past the valves and membranes creating a vacuum seal that pulls the nipples, stimulating lactation. Truth: Seeing your nipples stretch that far can make you feel like you’re hooked up to an industrial milking machine, but it’s kind of cool, too.

3. The breastmilk squirts into the breast shields and down into the bottles (not into the tubing!). It takes about 15 minutes on average to pump, although your experience (and output) may vary. Store milk in the screw-on bottles, or transfer into storage bags.

4. The motorized pump works in two phases: a fast stimulation speed (100 cycles per minute) imitates the frenzied nursing of a hungry babe for the first two minutes (or until you manually switch it, by hitting the letdown button as soon as you see milk) before readjusting to a slower speed of 60 cycles per minute. Most of the milk (96 percent) is expressed in the latter phase.

5. The suction is controlled on this panel. Be gentle with the girls in the beginning. Do not—I repeat, do not—put it on high the first time you pump. With experience, you can work your way up to higher speeds for faster expression, but pumping should never hurt.

6. This is the letdown button (press after your milk starts dripping into the bottle). The motor will automatically readjust to a slower and steadier speed.

7. This button allows you to customize and save your personal pumping session preferences.

A version of this article appeared in our May 2016 issue with the headline, “Anatomy of a breast pump,” on pp. 58-59.

Illustration by Vivian Rosas. 

Read more: Bottle service: how to store, heat and clean bottles of breastmilk or formula How to clean your breast pump How to combine breastfeeding and bottle-feeding