Will Decreasing Our Flange Numbers Increase Our Breastfeeding Numbers?

In recent years, more parents are relying on breast pumps as part of their feeding journey. Whether it’s for returning to work, a weekend away or supporting a premature baby in the NICU, pumping has become a critical tool for many families. Yet one persistent challenge parents face continues to appear in my consultations: flange sizing.

Flange fit is more than just comfort—it directly affects milk output, breast health, and a parent’s long-term success with breastfeeding or chestfeeding. Unfortunately, many parents are still handed a standard 24mm flange without guidance, even though research and clinical experience show that flange size needs to be individualized.

This raises an important question: could decreasing our flange numbers actually increase our breastfeeding numbers?

Why Flange Size Matters

The flange (also called a breast shield) is the part of the pump that fits over the nipple and areola. When it is too large, excess breast tissue gets pulled into the tunnel, often causing pain, swelling, and inefficient milk removal. When it is too small, the nipple may rub against the sides, leading to discomfort and abrasions. Both scenarios can decrease output and discourage parents from continuing their pumping routine.

A poorly fitting flange can also contribute to clogged ducts, mastitis, and nipple trauma—complications that often lead parents to supplement with formula earlier than planned, or to stop breastfeeding altogether.

The Shift Toward Smaller Sizes

In the past, 24mm and 27mm flanges were considered the “standard.” But in practice, I often find parents need smaller sizes—21mm, 19mm, 17mm, or even 15mm. Many are surprised to learn that their comfort and milk output improve dramatically when they switch to a smaller size.

This shift toward offering a broader range of flange sizes reflects a growing awareness that “one size fits all” has never been true for lactation. Just as shoe sizes vary widely, so do nipple diameters.

Could Smaller Flanges Support Longer Breastfeeding?

If parents had access to proper sizing from the beginning, it could make a significant difference in their breastfeeding journey. Better fit means:

More efficient milk removal, which protects supply

Less pain and nipple trauma, reducing the risk of early weaning

Fewer complications, like clogged ducts and mastitis

Greater confidence and willingness to continue breastfeeding or chestfeeding

By decreasing flange numbers—meaning expanding access to smaller sizes—we may help more parents maintain their milk supply, meet their feeding goals, and extend the duration of breastfeeding.

Moving Forward

For healthcare providers, lactation consultants, and pump manufacturers, the message is clear: flange sizing should never be overlooked. Offering a variety of sizes, teaching parents how to measure their nipples, and providing follow-up support can dramatically change outcomes.

The solution may not be as simple as “smaller is always better,” but the trend toward smaller flange options is a step in the right direction. By respecting the individuality of each parent’s body, we can increase both comfort and success—and ultimately, increase breastfeeding numbers overall.

Book in for a mini consultation or full consultation today