The pads that come with your machine are the ones it was built around — sized for the job they do on your back, and built to hold on while you move about for hours. They were tested and registered with the machine as one system, which is also what keeps your warranty and cover in place. Other pads will often plug in. What has not been matched is everything after that.

Moisture. Your electrodes grip and conduct for as long as the gel holds it — so when the grip fades, a small drop of water brings it back. A slippery pad is the opposite: it needs time, not water. Store them on their film, sealed and out of the sun. A pad that will not hold even after water is done.

One pack covers the day itself. A second is worth having if you plan to use your Elle TENS® from 37 weeks, or you would rather labour started on an unopened pack. Your machine comes with one sealed pack of four pads — and a pair has one more job in the first days with your baby.

The contractions are at the front. The pads go on your back — and that is deliberate. Maternity TENS electrodes are the four large pads that carry the stimulation from your machine to your skin, sitting either side of your spine where the signals from every contraction travel. Each pad is 40 x 100mm, with a medical-grade hypoallergenic gel made for hours on skin.