Breast Shield Sizing: How to Get the Best Flange Fit

Breast Shield Sizing: How to Get the Best Flange Fit

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One of the most important things when pumping breast milk is making sure that you have the best flange fit so that pumping isn&#;t painful. Here&#;s everything you need to know about breast shield sizing.

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What is a breast shield?

Breast shields (also called &#;flanges&#; or &#;horns&#;) are the part of the pump that fits around your breasts.

When the pump is set up and turned on, your nipple is sucked into the flange tunnel, pulling the milk out.

Standard size breast shields (often 24mm) will come with your breast pump. However, many people need a different size &#; below is an unscientific Instagram poll I recently did.

How are they sized?

Breast shields are sized based on the diameter of your nipple in millimeters.

This means that it&#;s possible to have large breasts, but still need a small breast shield size. Sizing is based on nipple size, not breast size.

Why is using the correct breast shield size important?

Using the incorrect breast shield size can cause three major problems &#; pain while pumping and damaged nipples, decreased milk output, and clogged milk ducts.

(You don&#;t want any of these, which is why it&#;s a really good idea to make sure you have the right size!)

How does pumping with the wrong size cause pain?

• If your breast shield is too small, your nipple won&#;t be able to move freely in the flange tunnel, which can cause nipple pain because the fit is too tight.
• If your breast shield is too large, too much of the tissue around your nipple gets pulled into the tunnel. The agitation related to areola getting pulled in where it shouldn&#;t can bruise that tissue and cause pain and inflammation.

How does it result in decreased milk output and clogged ducts?

Pain inhibits letdown, so if pumping hurts, it will be harder for you to get your milk to letdown.

Additionally, if there is pressure from your flanges where it shouldn&#;t be, this can cause the ducts to flatten or constrict the flow of milk.

And if milk isn&#;t being removed effectively because your flange size is not correct, you may be more susceptible to clogged milk ducts.

What are some signs that your flanges don&#;t fit correctly?

Here are a few reasons to consider using a different breast shield size:

• You&#;re having pain when you pump.
• Your nipple can&#;t move freely in the tunnel and turns red.
• More than a little areola is pulled into the breast shield.
• Your breasts don&#;t feel empty after 15-20 minutes of pumping.
• Your nipples stretch far into the flange, almost to the end of the connector.

What sizes are available?

Different breast pump manufacturers sell different breast shield size options. Here are a few examples:

• Spectra: 16mm, 20mm, 24mm, 28mm, and 32mm
• Medela: 21mm, 24mm, 27mm, 30mm
• Motif: 16mm, 19mm, 21mm, 24mm, 28mm, and 32mm

Additionally, there are several companies such as Nenesupply and Maymom that make aftermarket breast pump replacement parts, and these may include additional sizes. For example, Nenesupply sells the same sizes as listed above for Spectra, but they also sell 21mm breast shields, if you need something slightly larger than 20mm.

How do you find the correct breast shield size?

So what should you do if you think you might have the wrong breast shield size? You have a few options to for breast shield sizing.

1. Measure with a ruler

You can download a printable breast shield size ruler and use that to measure your nipple size.

Below is an example of what these rulers look like. You cut out each of the circles, and then see which circle best fits your nipple after you finish pumping.

Legendairy Milk sells a ruler for flange sizing that you can use to measure your breast shield size &#; use 15EPUMP for 15% off.

2. Get sized

You can also ask a lactation practitioner to size you for flanges.

For more Flange Too Biginformation, please contact us. We will provide professional answers.

You may be able to find someone local to you who can help you in person. When making the appointment, I would be clear that you&#;re asking about pumping so that you know they will be able to help you.

Some services also help you get sized virtually via photos and video.

3. Try several different sizes

Another option, if you don&#;t want to measure/are finding it confusing or if you are still having pain with the size that you measured for, is buying and trying several different sizes.

One way to do this is to buy one size up and one size down from what you measured for or what you&#;re using now, and see what feels best.

The upside is that you can be sure the size you&#;re using is best for you compared to other options. The downside is obviously that you might end up buying a lot of sets of breast shields that don&#;t fit, and that adds up.

Is it possible for each side to need a different size breast shield?

Yes. It&#;s possible to have nipples that are two different sizes; some amount of asymmetry between breasts is normal. (Just like it&#;s possible &#; even common &#; have lopsided breast milk output from your breasts.)

It&#;s a good idea to measure both sides to ensure each side has the correct size.

If you need different sizes, just buy one of each size, and then you have two sets of breast shields that will fit you perfectly.

Can your breast shield size change over time?

Yes. Therefore, if you start feeling discomfort when pumping, it&#;s good idea to measure yourself or try a different size even if you were sized before.

What if you can&#;t find a size that fits you?

Sometimes folks try a ton of different breast shields and can&#;t find one that works. This can happen for a few reasons.

In between sizes

If you are in between sizes, BeauGen cushions are a good option, as they will reduce your flange size by about 2mm.

So for example, if you measure yourself at 26mm and have a Spectra breast pump, you could try using 28mm flanges with cushions.

Beaugen cushions are available on amazon or buying directly from BeauGen.

Elastic nipples

Another cause for this can be elastic nipples. With elastic nipples, the nipple stretches to fit whatever size breast shield is being used &#; sometimes reaching to the end of the tunnel.

Usually, with elastic nipples, you will want to try breast shields that are a different shape and material (silicone), such as Pumpin Pals or LacTeck BabyMotion flanges. These (along with BeauGen cushions) can sometimes help keep your nipples from stretching out.

You can use the code EPUMP10 for 10% off LacTeck BabyMotion flanges.

More on alternate breast shields options here.

Have you struggled with breast shield sizing? Feel free to ask any questions about flange fit in the comments!

A breast pump flange, also known as a breast shield, is a plastic or silicone piece that fits directly over your nipple to form a seal. When you begin to pump, this creates a vacuum seal that should only draw your nipple into the flange tunnel for maximum milk extraction. Many pumps come with 24mm flanges, but you may need to select smaller or larger flanges based on your measurement and experience when pumping. 

Having the wrong flange size can affect milk supply, cause nipple pain and damage, and can even lead to clogged milk ducts (ductal narrowing) and mastitis.  Having the correct flange size is also key for allowing adequate pump suction and milk removal.

For first-time pumps, seeing a lactation specialist can be helpful in determining the correct flange size for your nipple size as well as areola density and fullness, and can make a big difference in your pumping experience. 

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