What’s the difference between open- and closed-system breast pumps?

Discover the truth about open- and closed-system breast pumps to help you make an informed decision when choosing a breast pump and expressing milk for your baby

If you’re thinking about buying or renting a breast pump and have been doing your research, you may have seen some models described as ‘closed system’ and others as ‘open system’. But what do these descriptions actually mean? And why do they matter? Read on to find out…

What do open system and closed system mean?

These terms generally refer to whether or not there’s a barrier (sometimes called a ‘media separation’) between the breast pump and your expressed breast milk.

A breast pump with a milk barrier is known as a closed system as it’s ‘closed off’ from the milk. The barrier prevents the milk overflowing and leaking into the pump mechanism, and helps ensure your expressed milk travels through a hygienic route.

An open-system breast pump doesn’t have a milk barrier – but bear in mind that the risks of contamination are extremely small even if you do have this type of breast pump.

What is ‘overflow protection’?

It’s worth knowing that ‘closed system’ and ‘open system’ are not clinical or medical definitions, and different breast pump manufacturers may use them differently.

For this reason, we at Medela prefer the term ‘overflow protection’, as that’s the milk barrier’s main purpose: to stop milk from overflowing and entering the pump.

In addition, there’s actually no such thing as a completely ‘closed-system’ breast pump – all breast pumps need some air to flow in and out of them so the vacuum can work.

Where can I find the milk barrier?

It varies between breast pumps, but usually between the tubing and the motor, or between the breast shield connector and the tubing.

The latter option is increasingly common in the latest next-generation breast pumps. This is because it protects the tubing as well as preventing milk overflow.  

What are the benefits of Medela’s next-generation breast pump connectors?

Having the overflow protection within the breast shield connector means you can pump in a more reclined, comfortable position, because you can be confident your expressed breast milk won’t get into the tubing. This is a big bonus, as being comfortable and relaxed while pumping helps your milk to flow – for more on how to make the most of your pumping sessions, see our article on breast pumping tips.

Another plus for busy mums is that this type of breast pump is easier to keep clean and maintain. Because the overflow protection minimises the chance of moisture entering the tubing, you’re less likely to need to clean and sanitise it. 

Assembling Medela’s next-generation breast pump connectors is also uncomplicated and intuitive. The milk barrier is an easy-to-handle flexible membrane that can only be placed in one position inside the connector.

In addition, the connectors themselves are simple to clean, with as few parts as possible to wash and sanitise. And, as you’d expect from Medela, all plastic components are made without the chemical BPA and comply with international safety regulations.

What if I see moisture in my breast pump’s tubing?

If moisture does appear in the tubing of your closed-system breast pump, condensation is likely to be the culprit. This can happen if any parts are not completely dry when you start pumping.

If you spot water droplets in your breast pump tubing, you’ll need to clean and sanitise it or replace it according to the product instructions.

Are all closed-system breast pumps the same?

While many breast pump makers claim their products have closed systems, they’re not all created equally. If they are poorly designed, a closed-system breast pump can actually reduce the amount of milk you can collect, or even increase the risk of contamination.

A closed-system breast pump isn’t necessarily more hygienic either. Bacteria and mould growth are generally linked to poor cleaning, so if a closed-system pump isn’t cleaned properly it can still harbour germs. Every breast pump is designed a little differently, so you’ll need to follow the cleaning instructions from your pump’s manufacturer.

A closed system doesn’t necessarily mean better performance either. Some manufacturers have compromised their breast pumps’ effectiveness to have a closed system.

What makes Medela breast pumps different?

When you use a Medela breast pump, you’re using a medical device that’s been developed and refined through decades of scientific research to meet strict quality and safety standards.

And at Medela we go above and beyond the regulations, by clinically testing all our products with mums to make sure they’re effective and meet the needs of parents and babies.

Plus all our next-generation breast pumps have a milk barrier for overflow protection, so you can feel happy, relaxed and comfortable when pumping. And remember, a happy mum equals more breast milk and a happy baby!