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 find conflicting 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 website does say this:
'All products which come into contact with breastmilk are BPA-free and easy to clean, no matter whether you boil, disinfect or clean them using our microwave bags.'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:
'A closed collection system has a barrier or diaphragm that separates the pump tubing from the horn. In this design, the suction of the pump motor lifts the diaphragm to create a vacuum within the collection system to extract milk. An open system allows for the free passage of air/suction.'
'When an open collection system is used, the pump’s suction can cause milk to overflow it into the collection system tubing, which may lead to milk particles being drawn into the pump motor.'
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 code compliant, 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):
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Inside, the two apertures i) where the expressed milk comes into the flange, and ii) where the pump tubing enters the bottle are really quite close together:
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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.
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Although the opening for the tubing is slightly further away from the milk inlet in this design, there is still no physical barrier separating the tubing and the milk being expressed. The milk and the air flow into the pump can mix freely.
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So my husband and I conducted our little experiment. We were looking for signs of contamination within my pump unit. Obviously if milk is being drawn back inside the pump then it's impossible to sterilise the unit without taking it apart completely.
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We didn't have far to look I'm afraid.
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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 is clean!
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).
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And here's a closer look at the clear plastic (silicone) unit which meets the tubing and houses a couple of valves.
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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:
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No matter how clean your second hand breast pump looks from the outside, it's highly unlikely that anyone has opened it up to clean inside. In their online cleaning instructions Medela do not say that you need to clean inside the pump. However, elsewhere the pump's literature (and oddly not located within the section 'cleaning and hygiene'?), they say you can run warm soapy water through the pump in order to clean these internal parts: page 9, section 'if there is an overflow' (thanks to Beth for pointing this out in comments).
Pumping soapy water through the inside is certainly a good idea if you notice milk/ vapour being pulled back up into your pump, BUT IT'S NOT THE SAME THING AS STERILISING, and therefore it's a bit of a cop out in my opinion. They give the impression that sterilising the external parts and rinsing out the internal ones is sufficient, but the bottom line is this: you can't sterilise the inside of the unit.
Quite obviously from the photographs, I didn't realise it was possible to run water inside the pump or I would have done so. However I was - at least - aware that milk could travel back into the machine causing contamination. Were you?
If you were to buy a second hand pump, how would you know if the previous owner had cleaned the inside or not? Would you know to clean inside the unit this way once you bought it? Does any of this even matter since you can't actually sterilise it?
Pumping soapy water through the inside is certainly a good idea if you notice milk/ vapour being pulled back up into your pump, BUT IT'S NOT THE SAME THING AS STERILISING, and therefore it's a bit of a cop out in my opinion. They give the impression that sterilising the external parts and rinsing out the internal ones is sufficient, but the bottom line is this: you can't sterilise the inside of the unit.
Quite obviously from the photographs, I didn't realise it was possible to run water inside the pump or I would have done so. However I was - at least - aware that milk could travel back into the machine causing contamination. Were you?
If you were to buy a second hand pump, how would you know if the previous owner had cleaned the inside or not? Would you know to clean inside the unit this way once you bought it? Does any of this even matter since you can't actually sterilise it?
Remember that once you switch the pump on, the air is circulating inside the non-sterile pump every single time it sucks, and that air can also mingle freely with the milk you are expressing. If milk can be sucked towards the pump on the 'in' suck, then of course it can also travel back towards the bottle on the 'out' - potentially bringing with it residue/ spores from inside.
Doesn't seem like a very 'closed' system to me...
And so we journey further into my ex breast pump...
[I should state at this point that I was never a 'big time' pumper - I pumped for roughly a year, I never shared my expressed milk and I didn't donate anywhere. I used it simply when I was apart from my daughter and to store moderate amounts of milk in my freezer for our own use. Had I been working full-time and having to express several times a day for months on end, the inside might look different again.]
Eventually we found the 'diaphragm' section of the pump. So it DOES have one! This membrane ultimately completely separates the pump motor from the tubing and valves. However, does this mean that the pump is 'closed' system?
The wikipedia definition of a closed system (where the diaphragm separates the tubing from the flange) would suggest that it's not.
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[NB - in locating this diaphragm my pump really did 'bite the dust', so unless you are happy to say goodbye to your unit, I suggest you don't try this at home...]
Hmmm, white residue there too.
So how does the Medela Swing pump differ from a truely 'closed' system pump?
It's amazing how simple the difference is actually. Here's the tubing set/ bottle/ flange from my new pump.
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The 'flexible membrane pot' forms a complete, impermeable barrier between the tubing and the flange where the milk comes in. It also acts as a diaphragm, and helps to create the suction when the pump is in operation and as such is airtight. You can see from the photograph above how easy this all is to take apart, clean and sterilise, and there's no risk of the milk travelling back towards the pump unit. Replacement parts are readily available and cheap.
So let's talk money. A Medela Swing pump costs something in the region of £85 - £95 new and something like £50 second hand. The pump I've just bought costs roughly £139, including the extra flange/ tubing to convert it to a double. Money well spent since I can loan or sell this pump on second hand with a clear conscience!
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's Swing 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:
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:
'Use by more than one user may pose a health risk, performance questions, and voids the warranty' (6 months).
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:
If milk particles in the tubing go unnoticed, mold can begin to develop in the tubes, as well as the pump motor. This puts your expressed breastmilk at risk of being contaminated, since it is exposed to the mold, even if the tubes are thoroughly cleaned or replaced.When using a closed system to express milk, the barrier in between the collection kit and the pump tubing prevents outside air from being exposed to your breastmilk. '
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 a replacement 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.
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'?
[ETA: Another high-end Medela pump, the Lactina, which is frequently used in hospitals, works on a 'piston system' (it's not a diaphragm pump like the Swing). This piston can be taken apart and sterilised, so it's different again and I think milk is very unlikely to come into contact with the unit itself. For a definitive answer about whether the system is 'closed' though, you'd need to contact the manufacturer.]
[ETA: Another high-end Medela pump, the Lactina, which is frequently used in hospitals, works on a 'piston system' (it's not a diaphragm pump like the Swing). This piston can be taken apart and sterilised, so it's different again and I think milk is very unlikely to come into contact with the unit itself. For a definitive answer about whether the system is 'closed' though, you'd need to contact the 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.
What's more - I'll ensure that any pump I do recommend is made by a company who are fully WHO code compliant, such as ARDO*, Hygeia, or Ameda. Sadly, Medela are not, neither are Avent, Tommy Tippee, NUK, Nuby, or Chicco (and others). You can find out more about which companies choose not to comply with the code here.
You don't have to pay a fortune for a closed system pump.
You don't have to pay a fortune for a closed system pump.
For the record, I'm sharing this blog as 'information' - because it is topical and because I was asked to. Information such as this might be particularly relevant to milk-sharing mums or to someone donating to a milk bank. I think it's also relevant if you're thinking of buying or selling a second hand Swing pump. It's obvious that I used my Swing pump quite happily and with no obvious ill-effects for at least a year - BUT - I didn't share it, and I never donated or shared milk with another mum.
If your child is eating solids or sucking on whatever they find on the floor, you may feel there is no need to sterilise at all. In fact there is a lot of conflicting information about sterilising floating about, and some of it will only apply if you're formula feeding, as breast milk has antibacterial properties of it's own. However, if you were looking after a vulnerable child or milk-sharing you might want to think carefully about what kind of pump you use, and opt for one which can be completely sterilised throughout.
If your child is eating solids or sucking on whatever they find on the floor, you may feel there is no need to sterilise at all. In fact there is a lot of conflicting information about sterilising floating about, and some of it will only apply if you're formula feeding, as breast milk has antibacterial properties of it's own. However, if you were looking after a vulnerable child or milk-sharing you might want to think carefully about what kind of pump you use, and opt for one which can be completely sterilised throughout.
