In recent Twitter discussions with some fellow breastfeeding nerds (and I mean that lovingly..) some confusion has arisen about whether or not the very popular Medela Swing Breastpump is suitable for sharing/ selling on/ buying second hand.


At least one blogger has stated clearly that the Medela pumps are NOT built with a 'closed' (and therefore more hygienic) system and should be avoided. However, elsewhere online you will findconflicting information, some of which states that the Medela Swing Pump IS 'closed' system. There is confusion, not helped by the fact that the Medela website doesn't actually state clearly whether the Swing is closed or open system. However, the websitedoes say this:
Sounds good.


Why does it matter whether the pump is 'closed' or 'open' system?


Well, it matters because if the pump allows expressed milk to travel back up the tube towards the pump unit, then there is a risk of some milk getting into the unit itself. And then you won't be able to sterilise it properly. With an open system pump unit this is a distinct possibility, with a closed one, it won't happen.


From our (amateur) investigations, we discovered that it all seems to depend upon the location of the 'diaphragm' which is vital to the pump's function as it helps to create the vacuum. This moveable membrane helps to generate suction in much the same way as a toilet plunger - by moving back and forth creating a 'suck'. Mini diaphragm pumps are frequently used in medical apparatus.


From wikipedia:
If expressed milk is not separated from the pump unit by a physical barrier, then it may be able to travel back up the tubes and into the pump unit as the machine sucks. This creates an avenue of contamination, and mould/ bacteria can (in theory) grow where it isn't possible to sterilise.


So, since I've just 'treated myself' to a brand new WHO codecompliant, closed system double pump (I'm hoping to donate milk once my baby is born, learn more here), my two year old Medela Swing Pump has just been sacrificed in the interests of settling this debate. Is the Medela Swing pump 'open' or 'closed' system?


I'd read online that expressed milk CAN travel back into the pump unit with the Medela Swing - but I'll be honest - I already knew that because I've seen it happening for myself. The following pictures should illustrate how this is possible:


This is the traditional flange/ tubing attachment for the Swing Pump (the one it's generally sold with):

2

Anyone who has expressed milk using a pump will know that sometimes the milk can back-up and collect (above the V-shaped 'lip-valve' or similar one-way valve) before splooshing down into the bottle - especially if you're pumping a lot of milk. When this happens it's easy to see how the pump could suck milk back up towards itself since the two openings are so close together with no barrier preventing the milk and air flow combining.


And it's also the same problem with this replacement attachment, which I bought separately. Often people who buy second hand pumps will buy new tubing and attachments such as this with the assumption that it makes the unit sterile. However, this may not be the case.

4

So my husband and I conducted our little experiment. We were looking for signs of contamination within my pump unit. Obviouslyif milk is being drawn back inside the pump then it's impossible to sterilise the unit without taking it apart completely.

6

Black mould (dirt?) where the end of the tubing meets the unit itself (about 1cm into the unit) - oh the shame...! Obviously, this could be superficially cleaned using a q-tip/ cotton bud - so a potential buyer of my second hand breast pump would be none the wiser - but just because something looks clean, doesn't mean it isclean!


Then we opened the pump unit right up. Here's the view of the area where the tubing enters the pump (bottom right of the picture).

8

What's the white stuff? My guess - dried milk, but milk which has been exposed to the air and therefore may have grown bacteria or mould. Nice.
If anyone wants to test this residue they're welcome to, please get it touch!


And look - it's all the way along this inside of this component:

10

Hmmm, white residue there too.
Đoạn này em chưa dịch :
Now I need to make something really clear. Medela do not claim anywhere on their website that the Swing pump is a 'closed' system. The American version of their website states clearly in it'sSwing information that this pump is a single user item. However,the Swing page on the UK site doesn't say anything about it, you actually need to download the right PDF file to learn this important fact.
I am quite sure many mums buying and selling the Swing pump don't realise it's actually being sold as a 'single user item'.


They also say that:
For comparison, the manufacturers of my new pump (read a review of it from a DBM giveaway winner here) say I can resell it without affecting the warranty (400 hours of pumping regardless of when you bought it). I guess that's tells you all you need to know.


This website explains the important difference between a pump like the Medela Swing, and a closed system pump very well:
One of Medela's 'top of the range' diaphragm pumps (the 'Symphony') does seem to offer the inclusion of something called the 'membrane cap'. This separates the tubing and the pump unit from the outside, and 'closes' the system in a similar way to the 'membrane pot' shown in picture 11. It means milk cannot travel back up into the pump unit, solves the contamination problem and it's available to buy separately (and relatively cheaply) as areplacement part.

However, the instructions for fitting this 'membrane cap' show that it actually attaches to the pump unit itself at the far end of the tubing, and not to the bottle/ flange end. Therefore it can't be used to modify the Swing pump, or any other Medela pump.


It's a shame that all Medela replacement bottle/ flange units couldn't be modified to include a space for something similar to the membrane cap, therefore enabling all pumps to be 'closed'? Surely something like that would be a doddle for a company like Medela? Such a simple adaptation that I wonder why it is reserved for only the 'Symphony'?

Lactina,=">Lactina," which="which" is="is" frequently="frequently" used="used" in="in" hospitals,="hospitals," works="works" on="on" a="a" 'piston="'piston" system'="system'" (it's="(it's" not="not" diaphragm="diaphragm" pump="pump" like="like" Swing).="Swing)." ="" This="This" piston="piston" >can=">can" be="be" taken="taken" apart="apart" and="and" sterilised,="sterilised," so="so" it's="it's" different="different" again="again" I="I" think="think" milk="milk" very="very" unlikely="unlikely" to="to" come="come" into="into" contact="contact" with="with" unit="unit" itself.="itself." For="For" definitive="definitive" answer="answer" about="about" whether="whether" system="system" 'closed'="'closed'" though,="though," you'd="you'd" need="need" manufacturer.="manufacturer.">
Speaking personally, I would never sell or lend my Medela Swing pump to anyone (that's why I destroyed it this morning!) - and in future I will ensure that I only recommend a closed system pump to my friends.