As you get started using your Spectra pump some mums find it helpful to explore breastshield size. Unfortunately, there's no way to know what your size will be before you start pumping. Your Spectra pumps comes with size 24mm breastshields in the box which will work for most mums at least initially - so don't panic! When you have had some practice and get used to pumping, you may find that you are better off with a different size. Getting your best shield fit is ultimately a matter of trial and error to determine what size gives you best comfort and output, regardless of measuring, but hopefully this guide will help you determine that a lot faster.

How to measure your best breastshield size

There are a few different techniques to get an idea of what your shield size will be, but most mums do tend to measure themselves incorrectly or too large - so shoot us a message so we can help! You will need to measure after pumping, as your nipples will swell during pumping. You can use a piece of string to measure around the base of your nipple and then divide by 3.14 (takes you back to circle geometry at school, right?). Or you can try measuring across the base of the nipple with a ruler - this is a lot harder to figure out than it seems though. You want to get end up with the diameter or width of the base of your nipple. Be careful not to include any swollen areola that is mistaken for nipple in the measurement. This can be tricky so doing it in front of a mirror or using a smart phone in selfie mode may be helpful.

Your bra / cup size doesn't matter here

We know you've focussed all your life on your cup size, but in this instance it really doesn't matter. Whatever cup size you are has no impact on your breastshield size needs. We also don't want to worry about your areola - areola should not enter the breastshield, so you need have a breastshield that is the best size for your nipple only that is not so large that it allows areola to be drawn in. Only the nipple size matters when it comes to sizing your breastshield. If you've already started using your breast pump and you're feeling like you might not be using the right size, here are some pointers:

Signs your shield is too large

• Your nipple is hitting the end of the shield
• Your milk output is lower than you expect
• Areola is being drawn into the breastshield
• Your nipple has a 'bunched' look because some of your areola is being drawn in and bunching up into the nipple.

Signs your shield is too small

• Your nipple does not fit into the shield to start with
• Your milk output is low.

Some extra tips to remember

• Feeling rubbing is not always the sign of a bad shield size. Using a balm, coconut oil or olive oil can really help reduce any rubbing or friction pain.
• Sometimes painful pumping or too large a shield size can make nipple excessively swollen. This is temporary and may ease with a better shield fit. (Ask us for help if you're not sure).
• Not getting any milk when pumping is very often a sign of poor shield fit or positioning (or not using a pump you respond to) not your milk supply. Concluding you don't have milk because you can't express any is a common mistake and means you need help!
• Shield positioning is also super important - it's helpful you have the best size for you, but more importantly, you need to make sure your shield is positioned well, that your nipple is centred down the shield and that you have a good seal of breast tissue to the breastshield behind the nipple.

What to do if you're still not sure

If you are having any doubts at all, then please just get in touch. A big part of our day goes in helping mums with shield fit and positioning, and we like to think we know something about it by now! You don't need to get this right all on your own, so get in touch and we'll help out.