A brief guide to correct Medela breastshield fitting

Benefits of a correct fit

A correctly fitted breastshield avoids compression of any milk ducts during pumping to ensure optimal breast emptying and maximum milk output. This will help a mother to maintain her milk production and support her lactation.

Criteria of a correct fit

The breastshield should closely surround the nipple but leave enough space so the nipple is not rubbing against the wall breastshield tunnel.

Before starting to express, holding the breastshield in position, the nipple should lie in the tunnel with approx. 3mm clear space all around (the nipple will swell during expressing).

The tunnel of a breastshield supplied as 'standard' with any Medela pump is 24mm in diameter.

breastshield - correct fit

Above illustration: During expressing the nipple will swell to fill the tunnel, but moves freely.

With the following checklist a mother can check if she is using the right breastshield size

1) Centre the nipple in the breastshield tunnel.

Is there 3mm space between the nipple and the tunnel walls?
Think of an imaginary circle 3mm larger than the nipple if viewed from the front.

2) Turn on the pump and check the following points:

Is her nipple moving freely in the tunnel?
Is minimal or no areolar tissue being pulled into the tunnel of the breastshield?
Does she see a gentle, rhythmical motion in the breast with each cycle of the pump?
Does she feel the breast emptying all over?
Is her nipple pain-free?

If her answer to any of the above questions is 'no', then she should try a larger or smaller breastshield.

Incorrect fit

Using too small or too large a breastshield may lead to impaired expressing because milk ducts could get blocked or milk ejection inhibited. Over time, this can result in reduced milk output.

Friction around the nipple (breastshield too small), or areola (breastshield too large), can cause discomfort and trauma which may cause a mother to only pump infrequently. Again, her milk production is jeopardized. Tissue breakdown due to nipple trauma carries the risk of infection and mastitis.

The mother needs a different size if the breastshield is...

breastshield too small
…too small because the nipple is not moving in and out of the tunnel easily. If you observe the nipple rubbing against the side (or sticking to the side) of the tunnel, the shield size is too small.

breastshield too large
...or too large because too much areola is pulled into the tunnel of the breastshield or because the breastshield does not make a good seal.

Medela breastshield tunnel sizing guide:

Diagrams ©Medela UK 2008. A majority of the above information on breastshield fitting sourced from Medela UK - Reproduced here by kind permission

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A brief guide to correct Medela breastshield fitting