May 11, 2023
By TLN

Finding your breast pump flange size with an IBCLC

As a breastfeeding parent, pumping can be a critical part of your feeding routine. Our number one recommendation for pumping success? Make sure you’re using the right flange size. 

Flanges or breast shields are cone-shaped plastic breast pump pieces worn over your nipples. They create a gentle vacuum for milk extraction designed to mimic a baby’s latch. Flange size refers to the diameter of the tube on the flange. 

Many new parents tend to rely on online self-measurement tools to find the right flange size. But because nipples are made of stretchy tissue, they can be hard to measure. Though these sizing tools can give you an idea of what size to start with, it’s always best to talk to your International Board Certified Lactation Consultant (IBCLC) when it comes to something as important as flange fit. Read on to learn more about how an IBCLC can be vital in helping you find the right flange size.

Flange sizing

All bodies are different, and that includes nipples! Different bodies need different sizes of flanges to work effectively. 

Although the standard flange size with your breast pump may be fine, an alternative flange size could work even better. Flange sizes increase in 3 mm – 4 mm increments (for example, 21 mm – 24mm – 27mm, and so on), so you may fall in-between flange sizes and need an insert to create the perfect fit. 

Nipples can also be asymmetrical, and you could need two sizes—one for each nipple. Your flange size can even change over time, as it’s common for your nipple size to change with continued breastfeeding and pumping.

How can you tell if your flange fits?

If your nipple fills the tunnel and is rubbing against the edges, the flange is too small. This may cause excess friction, pinching, or squeezing as the nipple is pulled against it.

If there is a lot of extra room in the tunnel and the flange leaves a swollen ring on the areola, the flange is too big. Your areola will be pulled into the flange tunnel, which can be painful, and the resulting inadequate areola stimulation can lead to low milk production.

The proper size flange will allow your nipple to fit centered in the flange’s narrow tunnel without any rubbing on its walls. When you finish pumping, your nipple should be free of pain and discoloration.

Find your flange size with an IBCLC

Because flange sizing is so important to pumping success, we recommend meeting with an IBCLC to find the proper fit for you. Unlike self-measuring, there’s no guesswork or uncertainty. As the highest-certified lactation experts, IBCLCs have the knowledge and experience to help find the right flange for you. 

Based on how your nipple fits in the tunnel of the flanges towards the end of a pumping session, your IBCLC can help you determine your perfect flange size and navigate inserts if needed.

Finding your flange size can be tricky—but it’s an important component of pumping successfully.

If pumping pain and discomfort persist even after finding the right flanges, you may be experiencing other breastfeeding-related issues. The same is true if you are concerned about milk output. Talk to your IBCLC about the challenges you’re experiencing so that they can help you address them, whether they’re flange-related or not.