What is TENS?

How does it work?

Is there any evidence for it?

How do I get hold of one?

What is TENS? 


So, you keep hearing word of this mysterious TENS machine that people use in labour, but what on earth is it? Is it a magical drug free alternative to an epidural? Tens, as in something between nines and elevens? 

TENS actually stands for transcutaneous electrical nerve stimulation, which is electrical pulses being applied through your skin. A TENS machine is a small machine with sticky electrodes that attach to your body, and has applications for pain relief in a variety of areas of the body. 

There are specifically made TENS machines that are for use in labour. They can be used constantly at a low level but then have a ‘boost’ button that can be pressed during a contraction to give an extra ‘kick’.  


How does it work? 


One theory of how it works is called the ‘Pain Gate Theory’.  

We only feel pain because the brain is interpreting signals and telling us we are experiencing pain.   

This theory is all about how the brain is not a fantastic multi-tasker (more so in some than others, right?) and therefore if the brain is receiving pain signals, but also receiving non-painful signals at the same time, it can’t fully focus on interpreting the pain. 

For example, if you hit your funny bone really hard, what do you innately do? Probably, you grab your elbow and put pressure on it, rub it or shake your arm. The reason we do this is so that the brain is getting the pressure, rubbing, or shaking information at the same time, and this may dampen down the amount of pain we are interpreting.  

So in labour, the theory is that if we put two pairs of electrodes delivering TENS, one at the level of the nerves going to the uterus (approximately just below bra strap level) and one at the level of the nerves going to the cervix and vagina area (approximately where the dimples are in your lower back), then the brain is going to be focusing on interpreting those messages as well as the labour pain.  

It’s interesting to note that some practitioners choose to deliver TENS in labour to acupuncture points instead of directly over the nerves on the lower back.  

The bottom line is that, unlike an epidural, this is not a ‘pain relief’ option. It doesn’t take away the pain. Instead, it’s a ‘pain distraction’ option. Similar to breathing and movement and positioning strategies that are taught in active birth workshops and Hypnobirthing courses.  


Is there any evidence for it? 


In a nutshell – very little.  

A review of the literature done in 2009 concluded that from the 17 studies that they looked at, they couldn’t definitively say whether it reduced pain scores.  

But importantly, there was one study that asked women retrospectively about their experience with TENS in labour, and two thirds of them said that they would use it again in future labours. The other third said that they didn’t find it helpful. 

There have been no studies that showed any negative outcomes to the mother or baby with the use of TENS, and most guidelines that I’ve seen say that women should be given the choice by their healthcare team to use it during their labour, amongst all of their other choices. 

In my experience, women have told me that they like the sense of having control over something, and they liked the ability to turn it up as their labour progressed and intensified.  

Many have told me that they weren’t sure if it was doing anything, but then they needed to take the machine off to go in the bath, or to have an epidural inserted, and then they realized the difference in intensity of what the contractions felt like without the TENS.  


How do I get hold of one? 


This will differ according to where you live and which hospital you’re delivering at, and I would recommend getting in touch with your birthing team about where the best place is for you to hire it from.  Alternatively you can purchase your own machine. 

So the cost privately is a sum of the weekly hire rate, the cost of the electrodes (which are one person use only) and the cost of the physiotherapy consult (minus a private health rebate where eligible).  

If you have access to a different TENS machine that is not maternity specific, I would advise getting good quality instruction on how to adjust the settings to be suitable, and remember that you won’t have the option of ‘boosting’ during a contraction like with the TENS machines designed for labour The physios at FitRight HQ are able to teach you how to use your TENS machine. 


If you’d like to learn more about pregnancy exercise, pelvic floor and how physiotherapists can help you during and after labour, check out our PregEd workshops here.

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