Hey Krisp

I have not personally used a Tens machine...but they can be very effective for early labor (but not any good for the bath or shower )

it works on the principle of stimulating the skin nerve fibres, flooding the sensory 'gate' in the spine, which helps to block the the sensations from the cervical nerve fibres...reducing pain

the same principle can be applied with soft skin stimulation...such as a tickle with the finger tips or light touch massage

hope this helps

xx yogababy