Breast Pumping – How Does A Breast Pump Work?

Breast pumping is an art, one that takes practice and a lot of patience. Not all breast pumps function exactly the same way, but understanding how a breast pump works will help you create a successful breast pumping experience.

Breast Pumping

How does a breast pump work?

Breast Pumping and nursing It’s a common misconception that a breast pump will suck milk out of the breast, when it fact it only provides stimulation which triggers a natural let down to occur, otherwise known as milk ejection. This natural letdown can be reached while breast pumping by mimicking a baby’s natural nursing rhythms. That’s what a breast pump does. Although there is a fair amount of suction going on, it’s only for stimulation purposes.

In order to understand the basics of breast pumping, and how a breast pump works, you need to understand the basic set up. Most breast pumps will come with either one or two collection units. A collection unit consists of the breast shield, also known as the flange, the connector that connects the shield to the bottle, and usually some smaller parts like a membrane or valve that allows the milk to flow through the shield to the bottle.

Medela PersonalFit Breast Shield - Standard size for breast pumping

Medela PersonalFit Breast Shield – 24 mm Standard

Aside from the motor, if there is one, the breast shield is probably the most important part of breast pumping. The breast shield is basically a cone shaped cup with a small tunnel on the end. The cup fits over the areola (the dark ring around the nipple) and the nipple should fit in the center of the tunnel. Now it’s important to understand that the size of the breast shield is not determined by the size of the breast, but by the size of the nipple. In fact, when you see that a breast shield is a standard size 24 mm, that means that the nipple tunnel is 24 mm’s wide. The nipple should fit in the center of the tunnel, and it should not rub on the sides as it’s drawn into the tunnel while breast pumping. If it does, then the breast shield or flange is too small. If you continue breast pumping with a breast shield that’s too small it can cause pain and discomfort, and has also been known to decrease one’s milk supply over time. Some breast pumps offer different sizes of breast shields, while others only offer one size fits all. This may be a determining factor for you if you feel that your nipples are larger than average. For more information about breast shield sizes, see Choosing The Right Sized Breast Shield.

Breast Pumping with a Manual Breast Pump

Medela Harmony - Manual Breast Pumping

Medela Harmony Manual Breast Pump

A manual breast pump is operated by squeezing a lever which in turn creates suction. The suction draws your nipple into the nipple tunnel of the breast shield much like your baby would draw the nipple into his/her mouth while nursing. For the most part, the faster you pump, the stronger the suction. Research has shown that when a baby first latches on during a nursing session, he/she will use a fast, short suckling motion to stimulate milk flow and let down.  Once let down has occurred, your baby will then use slower, longer sucking motions to nurse. With some practice, breast pumping with a manual breast pump can achieve the same results.

Breast Pumping with an Electric Breast Pump

An electric breast pump works the same way that a manual does, but instead with a motor that does all the work for you. Breast pumping with an electric breast pump is a whole lot less work, but it still takes practice. Some electric breast pumps, like the Medela Breast Pumps, offer two phases, one for stimulation which is the short, fast sucking motion, and one for expression which is the slower, deeper sucking motion. Most offer tubes that connect the pump motor to the collection unit. Air is sent through these tubes from the motor, creating vacuum and suction. The suction then pulls the nipple into the nipple tunnel of the breast shield, and then releases. This is called a cycle, one suction and release. For a breast pump to be efficient, it should provide 30 to 60 cycles per minute. This is as close as it gets to mimicking a baby’s natural sucking rhythm.

Breastpumping with AVENT

Philips AVENT Single Breast Pump

Some electric breast pumps offer freestanding pump motors with tubes attached, while other pump motors are directly attached to the collection unit, like the Philips AVENT Breast Pump. In this case, some manual operation may be required. The AVENT Breast Pumps are what I like to call cruise control pumps. You start out breast pumping with manual operation until you reach letdown or a comfortable speed and vacuum, then you press a button and the pump continues breast pumping at the same speed, just like cruise control.

Click here for a list of some of the Best Manual and Electric Breast Pumps on the market

Additional Reading

Breast Milk Supply: Is Your Milk Supply Low? – There are a number of concerns that go through a breastfeeding mothers mind, the most common being whether or not their milk supply is adequate.

Which Breast Pump Is Best For You? – Your lifestyle is the deciding factor when it comes to choosing which breast pump is best for you. Are you a stay-at-home mom, or a working mom? How much time will…


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