It’s important to use the right sized breast shield [aka flange] when pumping to ensure you are maximising your milk output and to prevent any pain or nipple damage. Did you know most women are actually sized between 15mm to 19mm? It seems ludicrous breast pumps only come with 24mm shields then, right?
The best way to determine your breast shield size is to try a few different sizes while you pump and see which is the most snug, comfortable and gives the best result. However, this isn’t always practical (or cheap!) so the next best thing is to measure your nipples.
How to measure your nipple
First, make sure your nipple is erect. Use your fingers to pinch and rub your nipple until it is hard. This step is really important as it can sometimes reduce your measurement by around 1-2mm.
Next, grab a ruler or measuring tape and measure the diameter of your nipples in millimetres. Ensure you are not including any areola in the measurement.
Choose a breast shield size that is as close to your nipple diameter as possible. For example, if your nipple is 16mm wide you would likely need a 17mm flange. If possible, it is best practice to try a few sizes around your measurement to see which is most comfortable. Using the same example of a 16mm diameter nipple, it would be ideal to try both 15mm and 17mm flanges.
It’s always a good idea to measure both nipples as it is very common to need different sizes.
If you have access to a printer, this nipple ruler is a great way to find your perfect fit.
How to know if the breast shield fits properly
While measuring your nipples gives you a great chance of finding the right fit, it’s not fool proof. It’s important to understand what signs to look out for to know if you need to size up or down.
Firstly, your nipple should fit snugly in the breast shield with very little room around it.
You should not feel pain or discomfort while pumping. Please note, pain or discomfort may occur for other reasons, e.g. your nipple isn’t centred in the breast shield (you should stop pumping and reposition the nipple), the pump vacuum is too strong (reduce the vacuum strength until you’re comfortable), or medical reasons such as vasospasm, mastitis, nipple thrush.
When the breast shield is the right size you will see the nipple gently and rhythmically pulling into the shield and your breast will feel soft when you’ve finished pumping. Milk spraying while pumping is a great indication you have the right size.
If your nipple is rubbing against the inside of the breast shield this is OK as long as the nipple is moving freely. If it is causing pain or stopping the nipple from being suctioned in properly, then size up. Make sure your nipple is centred so that it isn’t rubbing against one side.
If any areola is visibly being pulled into the breast shield this means the shield is too large. Other signs it’s too large includes your nipple swelling up, milk leaking out of the bottom of the flange, or your breast loses contact with the flange.
Where to from here?
Ultimately, you want to feel comfortable and pain free when pumping. As a bonus, the right sized breast shield should maximise your milk output so that you’re fully emptying your breasts. It can be a bit of trial and error!
If you aren’t sure whether you’re using the right sized breast shield, or need help measuring yourself, check out my breast shield fitting service. If you’re using a standard 24mm shield or you’ve been told to a larger size, there is an *extremely* high chance you’re using the wrong size. These sizes are very rare and a common cause for inefficient milk output.
If you’re needing a different size for your Spectra pump, you can shop here for sizes ranging from 13mm to 27mm.
Lastly, keep in mind that throughout your feeding journey your nipples may change size. It’s important to continuously check in with yourself and remeasure your nipples, it’s very common for them to change along the way.