Flex™ technology – a whole new pumping experience

Flex™ technology – a whole new pumping experience

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Flex™ technology – a whole new pumping experience

With a unique breast shield that you can adjust to your individual shape, Medela’s latest innovation was developed to make expressing easier and more effective – read on to discover how


When you’re pumping breast milk for your baby – whether occasionally or every day – you want the experience to be as comfortable and efficient as possible.

The breast shield – the part of the breast pump set that fits over your nipple and breast as you express – plays a key role in both comfort and efficiency during milk removal. With this in mind, Medela has always strived to offer a range of breast shield tunnel sizes to suit various nipple diameters, yet the teams at Medela wondered if the breast shield could be optimised even further.

Room for improvement

A breast shield has two main parts, a tunnel for the nipple to move back and forth in, and a wider, angled part that is placed over the breast, known as a flange. Ideally it should follow the shape of your breast and not compress it, as Dr Danielle Prime, Breastfeeding Research Associate at Medela’s Medical Research Department, explains: “The opening angle on a typical breast shield flange is 90°. Although this shape of flange works well, it doesn’t look like many breasts I’ve come across in my research career!

“We wondered if this part of the breast pump could be impacting milk removal, as well as fit and overall comfort for the mother. We knew it could potentially be optimised,” she says.

Danielle and her colleagues used Medela’s world-first database of 3D scans of lactating breasts to study the varying contours and shapes of the breast. “We found that the 90° angle could actually be quite restrictive for some mums,” she says. “We also discovered that the breast tissue may not have been getting into the flange easily, and the first part of the breast shield that touched the breast was the hard outer rim, which can cause discomfort.”

A new angle for expressing

This led the research team to experiment with breast shield flanges of different angles. They found a wide angle of 120° allowed mums to get their nipple further into the breast shield tunnel, but the rim came away from the breast, increasing the likelihood of a bad seal.

But with an angle of 105°, the team found exactly what they were looking for: “The 105° angle matched the contour of the breast really nicely. There was contact across the whole surface of the breast shield, and no compression points along the breast tissue. We thought this could really drive improved comfort and better support milk flow through the milk ducts,” says Dr Prime.

When pumping, your nipple needs to be centred in the tunnel, in order for it to move freely within it and prevent rubbing. The research team found that the 105° angle helped with this too. “By opening the flange angle slightly, the nipple can be in the tunnel when pumping starts. Today, for two thirds of mums the nipple is not in the tunnel at the start of pumping – it’s further back, away from the tunnel, so it’s hard to tell if you’re centred well,” says Dr Prime.

What’s more, your nipple diameter may increase by 2 to 3mm while pumping or feeding, so your tunnel size needs to be slightly bigger than your nipple, as Dr Prime explains: “Breast shield size is about nipple-tunnel matching, not bra size. We know a lot of mums choose their breast shield size because it says L on the box and they have large breasts. And that’s not correct.”

As a general rule, the breast shield tunnel should be 4mm bigger than the diameter of your nipple before you start to pump. The good news is Medela offers five tunnel sizes: “Use our fitting guide to make sure you get your optimal size based on your nipple diameter,” says Dr Prime.

New oval shape and soft rim

And the innovations didn’t stop there. In a great example of collaboration between experts – including user-centred design, engineering, research and product specialists – in addition to working closely with breastfeeding mums, the shield evolved to include an oval shape that could be rotated 360°. This meant that mums could move it around their breast to find a good seal.

“We’ve maintained the 105° flange angle all the way round that oval shape, with no one part more open than another,” explains Dr Prime. “So there’s no wrong way to hold it – mums can place the shield wherever it seems to fit to their breast shape nicely.”

“Depending on how full or drained the breast is, its shape and contour can vary, and the new shield can be adapted to this too: “Mums can now try different ways of holding the oval breast shield to see what feels best during pumping,” says Dr Prime.

Finally, Medela’s engineers also gave the new PersonalFit Flex™ breast shield a soft, smooth flexible rim. As well as offering a great fit and comfortable pumping experience, this allows the shield to seal gently to the breast shape.

Time to test

With the 105° oval shield ready, it was time to put it to the test. The team conducted four clinical studies with pumping mums – in hospitals, in homes, and in the lab at Medela headquarters in Switzerland.

“One test was an in-depth video recording of nipple movement during pumping. We had a little nipple-cam – which was fun! It enabled us to see how the dynamics of nipple movement differed with this new wider breast shield angle,” reveals Dr Prime. “What we saw was evidence that mums’ nipples behaved exactly as we’d predicted with the 3D scans.”

With positive results from this trial, the team moved on to testing with both exclusively and occasionally pumping mums in hospitals and at home. So what did they think?

Manuela, mum of two, Switzerland, was impressed: “I have a bigger bust size and always had trouble finding the right position with round breast shields. With the oval PersonalFit Flex™ breast shield it was easier to find my good position more quickly, and it was much more comfortable. I think the milk flowed better too – maybe because I found the position where the nipple should lie more easily.”

“Mothers feel like the PersonalFit Flex™ breast shield is designed to fit their breast shape better,” says Dr Prime. “This makes a lot of sense, because it allows the breast to form itself into the breast shield, rather than having to force the breast into the shield.”

Jeannine, mum of two, Switzerland, agrees: “The first time I tried the new PersonalFit Flex™ breast shield I put it on and thought, ‘Wow, that just fits!’. With other breast shields I needed two or three attempts of placing it until it sat properly. I put on the oval one and it fitted first time. It’s a pity I didn’t have the oval shield from the beginning – maybe I would have pumped better!”

“We’ve found that the majority of mums start with the shield in a horizontal position, some vertical and fewer oblique,” says Dr Prime. “And many mums then change the position or try different ways of holding it at subsequent pumping sessions.”

Improved milk yield

But perhaps the most important test focused on the efficiency of the new PersonalFit Flex™ breast shield – would it increase the volume of milk mothers express while pumping?

To find out, Medela’s scientists conducted a randomised controlled trial, inviting mums who’d been breastfeeding exclusively or predominantly for one to six months (and so had an established, consistent milk supply) to double pump for 15 minutes using one breast shield, and then do the same a week later using another. Half of the mums used the new oval 105° shield first, and the others started with a round 90° shield.

“We showed that when the mothers used the new breast shield they got significantly more milk volume,” says Dr Prime. “Looking at the ‘percentage of available milk removed’, we can also say that the shield significantly improved the drainage of the breast. The actual figures were 11% more milk volume and 4% more drainage, on average.”

How Flex™ technology offers flexibility

All of Medela’s bestselling electric breast pumps are now available with Flex™ technology: Swing Flex, Swing Maxi Flex and Freestyle Flex. All these breast pumps include two sizes of breast shield (the 21mm and 24mm) and also have a comfortable-to-hold connector. Or if you rent a Medela Symphony with PersonalFit™ Plus breast shield, you can buy the innovative new PersonalFit™Flex breast shield to use with it.

This worked for Manuela: “Normally when pumping, I have to check if the milk is still running well and that nothing has slipped. With this oval shield, I had the feeling that nothing moved and could lean back in a more relaxed position. I wasn’t so fixated on everything still sitting right.”

Jeannine agrees: “Because the breast shield was placed differently on my chest, I felt that the milk flowed better and I could lean back without milk jammed in the funnel.”

The fact that mums like Manuela and Jeannine felt more relaxed and comfortable while using the new shield could explain the increase in milk volume – stress and discomfort can hinder the hormone oxytocin, which is essential for the release of breast milk.

Another theory for why this new shield improves volume is because its form more closely matches the contour of the breast. When the let-down reflex occurs, the milk ducts in your breast increase in size by 68% to accommodate all the milk flowing through them towards your nipple. This new shape and angle appear to help that milk flow more freely.

And it’s this type of in-depth knowledge about the science of breast milk production that enables Medela to make these kind of innovations, as Dr Prime explains:

“Medela is a research-based company, it’s in our DNA. We invest in both basic ‘how lactation works’ research and applied research like this breast shield work that we’ve done with the mums. This means we’re better able to have a scientific basis for innovation and an evidence base for our products, to help more mums give their babies their amazing milk for longer. And so we say we bring research to life, which is essentially the story behind Flex™ technology – it’s a really good example of that.”