Finding Your Flange Size

Melissa Portunato MPH, IBCLC, RLC

Pumping should never hurt. Whether a mom is exclusively breast pumping or will be away from her baby for any reason, it will be significantly more efficient when the pump is set up correctly.  This includes proper flange sizing. If you are experiencing pain, discoloration, or rings around the areola when pumping, it is likely coming from your flange size. Having a poorly sized flange can cause breast damage, pain, and low milk supply, leading to premature weaning. 

Here are some quick tips to follow to find the perfect flange fit! 

Accurately Measure 

Finding the proper size for a breast flange is based on the diameter of the nipple, not the areola (the softer pigmented skin around the nipple).  When your nipple is centered inside the flange tunnel, it should only have a few millimeters (3-5) of wiggle room around the nipple. The entire nipple should fit comfortably without much, if any, of the areola entering the tunnel before pumping. But measuring only tells us a piece of the story. Some moms feel comfortable sizing up or down and changing sizes throughout their breastfeeding journey. Nipple size can fluctuate and can vary from side to side. We recommend measuring before pumping or nursing then adding 3-5mm to the diameter. Here’s our helpful fitting flange guide. 

How should it look when pumping?

For the most part, the nipple should stretch a little less than halfway down the flange when pumping. If it’s way past that – like hitting the backflow protector or end of the flange and you’re experiencing pain or low milk output, then it’s time to troubleshoot. The nipple should move freely with no rubbing against the sides, which could be mean it’s too tight. If the areola is being pulled inside the tunnel (more than 3-5mm), suction is breaking while pumping, or milk starts to drip from under the flange, these could be indicators the flange is too large. Typically a flange that’s too big will cause the areola to be pulled farther into the tunnel, but if a flange is restrictive, the nipple will rub inside the tunnel and stretch it farther too. It’s normal for nipple size to fluctuate or to use different sizes on each breast. Both too small or too large of a flange can be accompanied by pain, discomfort, discoloration, or low milk output.

Sizing options 

The Spectra Baby USA S1/2 and SG come with two sets of flanges – 24mm and 28mm.  Spectra Baby USA flanges come in 20, 24, 28, and 32 mm. Flanges are relatively inexpensive and completely worth the purchase to ensure you have the highest comfort level when pumping. 

What about “elastic nipples”? You can read more about them here. 

Several factors go into finding the perfect flange fit. It’s essential to assess how the flange looks, feels and whether you are pumping an adequate amount of milk. Expected milk output is 2-4oz combined every 2-3 hr if you are exclusively pumping or about half if also nursing your baby at the breast. A higher vacuum does NOT mean more milk. Lowering the suction vacuum can help if you are having pain or your nipple is pulling significantly through the flange tunnel. 

If your nipples are sore from pumping, treat your nipples by letting your very own breastmilk air dry over the area. Applying moist wound healing with a cool hydrogel over the nipple can effectively treat pain and soreness. Even after troubleshooting flange sizing, if pain continues, contact your local International Board Certified Lactation Consultant (IBCLC) or healthcare practitioner for help. 

Have questions on flange sizing or simply want to be sized by our IBCLC Team of flange sizing experts? Schedule here. Follow us on social media at Spectra Baby USA on IG and Facebook for weekly educational videos, support, and guidance. Let us make your pumping experience more enjoyable and help you achieve your breastfeeding goals! We believe in you, and we support you!