Does Your Medela Pump Flange Fit Correctly? Why 19mm Matters for Perth Mums

If you’re pumping with a Medela breast pump and experiencing nipple pain, reduced milk output, or discomfort after every session, there’s a strong chance your flange size isn’t right for your body. It’s one of the most common and most overlooked pumping problems — and it’s entirely fixable.

At Breastfeeding Solutions Perth, we know how much the right fit matters. That’s why we stock the Maymom Breastshield (flange) with valve and membrane, specifically the 19mm bottle neck size — designed for mums with smaller nipples who need a more precise, comfortable fit with their Medela pump.

In this blog, we’ll walk you through everything you need to know about flange sizing, why 19mm is a game-changer for many Perth pumping mums, and how the Maymom Medela-compatible flange compares to the standard options.

What Is a Breast Pump Flange (Breastshield)?

A breast pump flange — also called a breastshield — is the funnel-shaped plastic cup that sits directly against your breast during pumping. Your nipple sits inside the tunnel of the flange, and the pump’s suction draws milk through it.

The flange is the single most important fitting component of your entire pumping setup. If the tunnel diameter is too large or too small for your nipple, the consequences go well beyond discomfort:

• Nipple pain and soreness that worsens with every session
• Nipple swelling, redness, or bruising from rubbing against the tunnel walls
• Reduced milk output — poor flange fit means the pump can’t effectively empty the breast
• Blocked ducts from milk not draining efficiently
• Decreased supply over time as the breast receives inadequate stimulation

Many mums assume pumping is just supposed to hurt. It is not. Pain during pumping is almost always a signal that something — the flange size, the suction setting, or the positioning — needs adjusting.

How to Know If Your Flange Size Is Wrong

A correctly fitted flange should see your nipple moving freely in and out of the tunnel with minimal areola being pulled in. Here’s a simple guide to reading what you see:

Signs your flange is too large

• More than a small ring of areola is being drawn into the tunnel
• You feel pain or rubbing as the areola is repeatedly pulled in and out
• Milk output seems lower than expected despite good suction
• Your nipple looks compressed or misshapen after pumping

Signs your flange is too small

• Your nipple rubs against the tunnel walls during the pumping cycle
• Pumping is painful from the very first cycle
• You can see whitening or blanching at the base of the nipple during pumping
• The nipple cannot move freely inside the tunnel

Signs your fit is correct

• Your nipple moves freely and centrally in the tunnel
• Only a small amount of areola (2-3mm) is drawn in
• Pumping is comfortable — mild pulling sensation only
• Milk flows efficiently and the breast feels well-drained after the session

If you’re unsure about your flange size, Tracy Steele at Breastfeeding Solutions Perth can assess your fit during a home visit and help you identify the right size for your individual anatomy.

Why 19mm? Understanding Small Nipple Sizing

Standard Medela flanges are typically sold in 24mm and 27mm sizes. Many pumping kits include only one size — often 24mm — even though nipple diameter varies significantly from person to person.

For mums with smaller nipples, the standard 24mm flange is already too large. Nipples below approximately 17mm in diameter typically need a 19mm flange to achieve a proper, comfortable fit. Without the right size available, these mums often pump with ill-fitting equipment for weeks or months, experiencing ongoing pain and frustration that is entirely unnecessary.

The 19mm Maymom Breastshield fills exactly this gap.

About the Maymom 19mm Breastshield for Medela Pumps

The Maymom Breastshield (flange) with valve and membrane is a high-quality Medela-compatible replacement flange, available now at Breastfeeding Solutions Perth for just $18.99 per unit.

Key features

• 19mm internal diameter — specifically designed for mums with smaller nipples
• BPA-free and DEHP-free — no harmful plasticisers in contact with your milk or skin
• Steam safe — can be sterilised in a steam steriliser, microwave steriliser, or by boiling
• Includes breastshield, valve, and membrane — everything you need for a complete replacement set
• Compatible with all Medela pumps except the FreeStyle model
• Bottle neck design — fits standard Medela bottle neck connections
• Manufactured to US FDA standards for food-contact containers
• Retail packed and sealed by the manufacturer — arrives hygienically packaged

Medela pump compatibility

This Maymom flange is compatible with the following Medela pumps:

• Medela Pump In Style
• Medela Swing
• Medela Swing Maxi
• Medela Sonata
• Medela Symphony (personal-use kit)
• Medela Harmony (manual pump)

Please note: this flange is NOT compatible with the Medela FreeStyle pump, which uses a different connection system.

Why a Replacement Flange Is Worth Buying

There are several reasons Perth pumping mums regularly purchase replacement or additional flanges:

Wrong size in your original kit

Most Medela pumps ship with a 24mm flange. If your nipple diameter is smaller — typically under 17mm — you need a 19mm flange for a comfortable, effective fit. The Maymom 19mm is one of the most affordable ways to solve this problem immediately.

Wear and tear

Flanges are subjected to repeated steam sterilisation, mechanical stress, and the physical force of the pump motor. Over time, the plastic can develop micro-cracks, lose its clarity, or warp slightly — all of which affect performance and hygiene. Replacing your flange every 3-6 months is good practice.

Having a second set

If you’re pumping multiple times per day — at home, at work, or for a NICU baby — having a second complete flange and valve set means you don’t have to wash and sterilise between every session. A spare set keeps your pumping routine running smoothly.

Lost or damaged parts

Valves and membranes are small, easy to lose, and the first components to show wear. The Maymom set includes all three components — flange, valve, and membrane — so you can replace exactly what you need.

Flange Sizing: A Quick Reference for Medela Pump Users

Nipple diameter should be measured across the widest point of the nipple itself — not the areola. Measure after a feed, not directly before, as nipples can be temporarily larger immediately after feeding. Here is a general sizing guide:

• Nipple diameter under 17mm → 19mm flange (Maymom 19mm is ideal)
• Nipple diameter 17-20mm → 21mm flange
• Nipple diameter 20-22mm → 24mm flange (standard Medela)
• Nipple diameter 22-25mm → 27mm flange
• Nipple diameter over 25mm → 30mm or larger

These are general guidelines. Individual anatomy, breast tissue firmness, and pumping technique all affect which size works best in practice. If you’re unsure, Tracy Steele at Breastfeeding Solutions Perth can advise you directly — both through the online shop and in person during a home visit.

Tips for Getting the Most Out of Your Maymom Flange

Once you have the correct size flange, there are a few simple techniques that make a significant difference to your pumping experience:

• Centre your nipple carefully inside the tunnel before switching the pump on
• Start on the lowest effective suction setting and increase gradually — more suction does not mean more milk
• Apply a small amount of coconut oil or purpose-made lubricant to the inside of the flange tunnel before pumping to reduce friction
• Massage your breast gently while pumping to encourage let-down and improve drainage
• Pump for 10-15 minutes per session, aiming for 2-3 let-downs per session rather than just one
• Wash your flange with warm soapy water after every session; steam sterilise once per day
• Replace your valve and membrane every 4-8 weeks, or sooner if you notice reduced suction

Buy the Maymom 19mm Medela Flange Online — Perth Delivery Available

The Maymom Breastshield (flange) with valve and membrane — 19mm bottle neck — is available now at Breastfeeding Solutions Perth for $18.99. Order online for convenient delivery across the Perth metro area, including the northern suburbs.

At Breastfeeding Solutions, you’re not just buying a product — you have access to a certified lactation consultant who can answer your questions about fit, pumping technique, and milk supply. Whether you’re buying your first replacement flange or troubleshooting persistent pumping pain, Tracy is here to help.