What Are Breast Shields And Why Does Size Matter?
What are Breast Shields & Why is Finding the Right Size so Important?
September 24, 2019

What are Breast Shields & Why is Finding the Right Size so Important?

Babylist editors love baby gear and independently curate their favorite products to share with you. If you buy something through links on our site, Babylist may earn a commission.
Pinterest logo.
What are Breast Shields & Why is Finding the Right Size so Important?.
What are Breast Shields & Why is Finding the Right Size so Important?

Pumping can be very helpful for many new moms. You can continue to give your baby all the amazing benefits of your breast milk while getting back to your routine. Whether you are heading out for the afternoon, transitioning back to work or traveling to meet with family or friends, pumping can be convenient—and easier with the right accessories.

Having the right size breast shield is key. It’s not just a matter of comfort–using the correct size breast shield while pumping is important for efficiency too. Your end goal of pumping for your little one is to get as much out of your sessions as possible, and a breast shield that’s too large or too small can greatly impact the amount of milk you’re able to pump.

How to Choose the Right Size Breast Shield

A breast shield, also known as a breast flange, fits over your nipple while pumping. It helps express milk from your breast by creating a seal around your areola. The suction from the pump draws your nipple into the tunnel and expresses milk—which collects in the bottles that attach to the shield.

Your breast shield should feel comfortable throughout the entire pump session. A high-quality shield also maximizes your milk production and helps you avoid clogged ducts. That’s why it’s important to find a breast shield that fits you well. You might even find that each breast needs a different shield size.

What’s the difference between breast shields and nipple shields? A nipple shield protects your nipple while nursing your baby. Breast shields are only for pumping.

How to Measure:

  • Determine your optimal breast shield size based on your nipple diameter.
  • Using a ruler or measuring tape, measure the diameter (or distance straight across the middle) of your nipple at the base, in millimeters. Do not include your areola. (Tip: 1 cm = 10 mm)
  • Your breast shield size will be slightly larger than your nipple measurement.

Here’s more info:

Breast Shield Measurement Guide
Nipple Measurement Breast Shield Size
Up to 17mm diameter 21mm shield
Up to 20mm diameter 24mm shield
Up to 23mm diameter 27mm shield
Up to 26mm diameter 30mm shield
Up to 32mm diameter 36mm shield

Breast shields come with your pump, but they might not be the best fit for you. Test the shields—usually 24mm—that came with your pump to see if you need to adjust your size. How do you know if it’s the right size? While pumping, your nipple should be centered in the breast shield, should move freely in the tunnel with soft, rhythmic motions. If pumping feels uncomfortable or painful, another size may help.

Here are other signs you might need a different size breast shield:

  • Excessive areola being pulled into the tunnel
  • Your nipple or areola turning white
  • Redness in the area
  • You feel unexpressed milk after pumping

With the right size, you should be able to express all your milk after a pumping session without discomfort. For more detailed information read more about Breast Shield Sizing here.

The Comfy, Efficient Breast Shield

If you are pumping, it’s crucial to find the most comfortable breast shield that maximizes your milk output.

With the PersonalFit Flex Breast Shields by Medela, you can adjust the way the breast shield fits to find the most comfortable, most efficient position to pump—even as her breast shape changes. The PersonalFit Flex features four-way fit and a unique oval-shaped shield that adapts to your natural shape to help you find the pumping position that works for her. The best part of the shield? It’s clinically proven to remove 11.8% more milk per minute and promote faster let-down while pumping* than with traditional breast shields.

*Prime D. K. et al. Influence of a newly designed breast shield on the dynamics of milk removal: A randomized controlled trial poster. 6th Academy of Breastfeeding Medicine Europe Conference, 18-20 May 2018, Rotterdam, Netherlands; 2018.

This article is sponsored by Medela. Babylist’s free site, apps and emails are made possible by our sponsors. We limit our sponsored content to relevant partners that offer products and services we believe in and use ourselves.

This information is provided for educational and entertainment purposes only. We do not accept any responsibility for any liability, loss or risk, personal or otherwise, incurred as a consequence, directly or indirectly, from any information or advice contained here. Babylist may earn compensation from affiliate links in this content. Learn more about how we write Babylist content and the Babylist Health Advisory Board.