Choosing correctly fitting flanges, also known as breast shields, is an imperative step when you first begin to use your breast pump. Breast pump flanges fit directly over your nipple to form a seal around the areola, which creates a vacuum that gently draws your nipple into the tunnel for milk extraction. When the flange fits correctly, you will not only enjoy a more comfortable pumping experience but you will maximize the amount of milk extracted each time you pump. Let’s break down the parts and sizes of breast pump flanges to explain the 'why and how' behind this important part of your breast pump.

Breast Pump Flange Size Chart

Keep in mind that breast pump flange fit can change between the time you give birth and when you actually begin using a breast pump. What fits when you began breast pumping may change, so it is important to check your breast pump flange fit from time to time. Flange fit falls into the following categories:

breastpump flange size chart
Good Fit: During pumping your nipple is able to move freely in the breast pump flange tunnel. You will have space around your nipple and not much of the areola is drawn into the tunnel with the nipple.
breastpump flange size chart
Too Small: During pumping some, or your entire nipple rubs against the sides of the breast pump flange tunnel.
breastpump flange size chart
Too Large: During pumping more of your areola is drawn into the breast pump flange with your nipple. You may experience your areola rubbing up against the side of the breast pump flange funnel.

The 'COMFY' Test

When determining the right breast pump flange size, remember the word ‘COMFY’.  This term was specifically designed to help moms just like you remember five guidelines about breast pump flange sizing.

  • C – Centered nipple which moves freely.
    • Your nipple should move freely in the breast pump flange tunnel. You should not experience any rubbing. (If you do, this indicates your breast pump flange is too small).
  • O – Only a little or no areola tissue is pulled into the tunnel.
    • If your nipple is able to move freely in the breast pump flange tunnel you will notice there will be a gentle pulling movement in the areola each time your breast pump cycles. If there is no movement in the areola, your breast pump flange is more than likely too small.  On the contrary, if there is a lot of movement or a large amount of your areola is pulled into the tunnel, your breast shield is probably too big.
  • M – Motion of the breast is gentle and rhythmic with each cycle of the pump.
    • You should see gentle breast movement with each cycle of the pump just as you do with your nipple. Gentle breast movement indicates your breast is getting proper stimulation while pumping.
  • F – Feels comfortable pumping.
    • Using a breast pump should not be uncomfortable for you nor should it cause nipple pain or tenderness. If you experience pain or discomfort, more than likely you have an ill-fitting breast pump flange.
  • Y – Yields a well-drained breast.
    • Your breasts should feel soft after each use of your breast pump.

Incorrectly fitting breast pump flanges can affect how your breasts empty and yield problems with your milk supply.  If you use ill-fitting breast pump flanges for too long you could experience mastitis and even problems with low milk volume. We hope this breast pump flange size chart has helped you determine if your breast pump flanges fit correctly. If you have any questions regarding breast pumps or breast pump flanges, give us a call at 844-867-9890.  As always, if you are interested in getting your free breast pump through insurance, we can help with that as well. Simply fill out our Qualify Through Insurance form and you will be on your way to a new breast pump at no charge! We look forward to helping you and your growing family.