You may have heard about TENS from others who've given birth, or read about it in birth preparation materials. TENS is a simple, drug-free method of pain relief that you control yourself — and that can make the first hours of contractions far more manageable.

TENS machines are used by a growing number of people in labor. They have no known side effects for you or your baby and can be combined with most other methods of pain relief. Here's how TENS works and how to use it most effectively.

What Is TENS?

TENS stands for Transcutaneous Electrical Nerve Stimulation. A small, battery-powered device sends gentle electrical impulses through electrodes attached to the skin. During labor, the electrodes are typically placed on the lower back.

The device is small enough to hold in your hand or clip to your clothing. You control the strength and frequency of the impulses yourself via buttons on the unit.

How Does TENS Work During Labor?

TENS works through two mechanisms that both help with labor pain:

The Gate Control Theory

The electrical impulses activate nerve fibers in the skin that "occupy" the nervous system's capacity to send pain signals. Simply put: the signals from the TENS device block some of the pain signals from the uterus from reaching the brain. This is called the gate control theory.

Endorphin Release

At the right frequency, TENS stimulates the body to produce endorphins — the body's own pain-relieving substances. Endorphins build up over time, so the effect gets better the longer you use the device.

Start TENS early in labor. Because endorphin release builds up gradually, you get the best effect when you begin as soon as regular contractions start. Use a contraction timer to track when contractions become regular.

How to Use TENS During Labor

Electrode Placement

A labor TENS machine has four electrodes placed in two pairs on the lower back:

Upper pair — placed on either side of the spine, roughly at bra-strap level
Lower pair — placed on either side of the spine, roughly at the level of the dimples in the lower back (just above the tailbone)

The electrodes should not sit directly on the spine, but parallel to it on each side. Most labor TENS machines come with instructions for exact placement.

Step by Step

Attach electrodes to dry skin — moisture prevents them from sticking properly
Connect leads to the machine — check all four electrodes are connected
Start on the lowest setting — increase gradually until you feel a clear but comfortable tingling sensation
Use the boost button during contractions — most labor TENS units have a dedicated button that temporarily increases the strength
Lower the setting between contractions — maintain a low background stimulation to keep endorphin production going
Adjust as needed — increase strength gradually as contractions intensify

TENS should never be painful. If you feel discomfort or muscle twitching, the setting is too high. Lower it slightly and find a level that is strong but comfortable.

When Does TENS Work Best?

TENS is most effective in the early and active phases of labor. Many people find the effect decreases somewhat toward the end of the active phase when contractions become very intense.

TENS works best:

From the first regular contractions through the early active phase
For back labor (pain in the lower back during contractions)
As a supplement to other methods like breathing and movement
At home, while you're waiting to go to the hospital

TENS is less effective:

During the pushing stage (second stage of labor)
When contractions are very frequent and intense
As the sole method of pain relief during a long labor

Combine With Other Methods

TENS works well alongside gas and air (nitrous oxide), breathing techniques, heat, massage, and movement. Many people use TENS in early labor and add gas and air or an epidural as the need for stronger pain relief increases.

The TENS machine must be removed if you are going into water (a bath or birthing pool) or having an MRI. Electrodes and water are not compatible. It must also be removed before an epidural is placed.

Benefits of TENS

No side effects for the baby — TENS does not affect the baby
No side effects for you — apart from possible skin redness where the electrodes sit
Full freedom of movement — you can stand, walk, sit, and change position freely
You're in control — you control the strength and can switch off at any time
Can be used at home — start before you go to the hospital
Works quickly — the impulses work immediately; endorphins build up over minutes
Can be reused — many devices can be used for multiple births

Limitations

Limited pain relief — TENS doesn't remove all pain, but makes it more manageable
Must start early — works best when started early in labor
Cannot be used in water — not compatible with birth pool
Electrodes can slip — sweat can cause them to move

Where to Get a TENS Machine

Hire/Rent from a Pharmacy

Many pharmacies hire out labor TENS machines. Contact your local pharmacy in good time — ideally around 36–37 weeks. Hire prices vary.

Buy Your Own Machine

Labor TENS machines can be purchased from pharmacies or online shops. Prices vary. The advantage is that you can practice beforehand and use it for multiple births.

Borrow from the Hospital

Some hospitals have TENS machines available to borrow. Check with your hospital in advance.

Order or hire your TENS machine around 36–37 weeks so you have time to try it at home before labor. Practice attaching the electrodes and using the boost button — it's much easier to learn without contractions.

How to Prepare

Get the device in good time — hire or buy around 36–37 weeks
Read the instructions — understand the buttons and settings before you need them
Practice with your partner — let them practice attaching the electrodes to your lower back
Take it to the hospital — pack it in your hospital bag
Include it in your birth preferences — note that you want to use TENS
Have spare batteries — nothing is worse than a dead battery in the middle of a contraction

Frequently Asked Questions

Is TENS scientifically proven to work?

Research on TENS during labor is mixed. Some studies show an effect, while others are inconclusive. What is clear is that many laboring people experience significant benefit, the method is safe, and it has no side effects. Many hospitals recommend TENS as part of their pain relief options.

Can I use a regular TENS machine or do I need a special one?

There are TENS machines made specifically for labor. These have a boost button that lets you quickly increase the strength during a contraction. A regular TENS machine can also be used but lacks this feature.

Can TENS replace an epidural?

For some people, TENS is sufficient pain relief throughout the entire labor. For others, it's a good supplement in the early phase. It's completely fine to start with TENS and move on to stronger pain relief as labor progresses. Always have a plan B.

When should I remove the TENS machine?

Remove it if you are going into water, if you are having an epidural, or if you feel it's no longer helping. Your midwife or nurse can guide you.

Can TENS harm the baby?

No. The electrical impulses are gentle and localized — they don't reach the baby. TENS has been used during labor for several decades without any reported harm to babies.

Summary

TENS is a safe, simple, and drug-free method of pain relief during labor. It is most effective in the early phase and can be combined with virtually all other methods. You control the device yourself, and it has no known side effects for you or your baby.

Prepare in good time by getting the device, practicing with your partner, and noting your wishes in your birth plan. That way you have one more tool in your toolkit when labor begins.

Sources: Cochrane Database — Transcutaneous electrical nerve stimulation for pain management in labor; NICE — Intrapartum care; WHO — Intrapartum care for a positive childbirth experience

Last updated: March 2026

TENS Machine During Labor — Natural Pain Relief