Breast Shield Fitting

Breast Shield Fitting


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Choosing your Medela breast shield size

Make sure to use the right breast shield size. It is an essential component of effective pumping, helping to optimise milk flow.

Understanding Medela’s breast shield sizing

Pumping should not hurt. For maximum comfort and pumping efficiency, Medela offers five breast shield sizes. This guide is a starting point to help determine your optimal size based on your nipple diameter.

Breast shield size chart


Step 1:

Using a ruler or measuring tape measure the diameter of your nipple at base (across middle) in millimeters (mm). Do not include areola.

Step 2:

Based on your measurement, determine your Medela breast shield size. Example: If your nipple size measures 16 mm in diameter, the recommended Medela breast shield size is 21 mm.


Test your breast shield size

• Start with the breast shield that came with your pump, or the size determined by measuring.
• Centre the nipple and gently hold the breast shield against your breast.
• Adjust for Maximum Comfort Vacuum to achieve optimum suction level.
• Refer to the images below while pumping in the expression phase (after the stimulation phase).

Correct fit

• The nipple is centred and moves freely.


too small
• The nipple rubs along the side of the tunnel.
• Try a larger size.
Too large
• The nipple and excessive areola are pulled into the tunnel.
• Try a smaller size.


Experiencing that “Feel Good Factor” – the Emotional Benefits of Breastfeeding

Another underrated benefit of breastfeeding for moms is that breastfeeding just feels good. Of course, there can be challenges for some moms with latching on and sore nipples. However, once you overcome these initial difficulties, most breastfeeding moms find feeding their babies from the breast physically enjoyable and fulfilling. Breastfeeding releases “feel good hormones” like oxytocin, which promote a sense of peace, love and attachment. Giving birth changes a woman’s life – it can give her a special sense of accomplishment, purpose, and happiness. Breastfeeding is a special gift that builds a stronger bond between a mother and a child.


Did you know?

• You may need a different size per breast.
• Your breast shield size will depend on your breast tissue and skin elasticity.
• Your breast shield size could change over the duration of your pumping experience.
• When you apply vacuum pressure, your nipple size could change.
• Pressing the breast shield too hard could block milk ducts.


Reasons to try a new size

• Does your nipple rub the tunnel sides to the point of causing discomfort?
• Do you see excessive areola being pulled into the tunnel?
• Do you see any redness?
• Is your nipple or areola turning white?
• Do you feel unexpressed milk after pumping?

If you answered «YES» to any of these questions, consider trying a new size by following the measuring instructions above. If you are still unsure that you selected the correct size, see a lactation consultant or breastfeeding specialist.

Watch our fitting animation at