Finding the right breastshield size to use with your breastpump is important if you want to maximise your efficiency when you pump, and also to maintain your comfort.
A common misconception is that breast shield size is related to your breast size. It isn’t. It is related to the size of your nipples (which, like your breasts themselves, may be different sizes). And to further complicate things, they are a different size when they are “at work”, compared to when they are resting.
An incorrectly fitting breastshield may result in reduced milk flow by blocking milk ducts, whereas discomfort or trauma may lead to an infection or mastitis, and may deter you from pumping.
The right breastshield size, on the other hand, will allow the breast to empty efficiently, maintaining your milk production, and ensuring baby gets more milk.
Your breastshield should fit over your nipple and form a seal around your areola. To test your breastshield size, you will need to check if your nipples rub the sides of the flange, or if the suction pulls excessive areola into the flange while you are pumping., You should not see any redness, and your nipple or areola should not turn white. If you notice any of these issues, you may need to try a different breast shield size.
You may like to refer to this great printout from Medela, – here – or speak with a breastfeeding consultant. The Australian Breastfeeding Association is another great resource.