Unlike 150 years ago, when there were very few options for pain relief during labour, there are now many different and effective forms of pain relief available. What’s more, a lot of the medication offered can also be used alongside natural methods.

It’s important to discuss the various forms of pain relief available with your midwife so they can help you assess which one is the most suitable.

While some women prefer a natural birth, for others, natural pain relief may not be sufficient enough to help them cope with the pain of labour, so a combination of natural techniques and medication may be best.

So let’s explore the pros and cons of the various options available so you can decide what works best for you.

What pain relief medications are available?

Entonox (gas and air)

Entonox is made up of 50% nitrous oxide gas and 50% oxygen. Nitrous oxide is the pain-killing element.

Entonox is delivered through a pipe or cylinder by the maternity bed and in many countries is available for home birth. It’s used by inhaling deeply through a facemask or a mouthpiece when a contraction is at its peak. The effect is rapid and then wears off almost immediately so using it in between contractions will not have any benefit. Many women report feeling lightheaded and even nauseous.

Advantages of Entonox

Useful when contractions are at their most intense and where the urge to push is strong.

You can use it throughout labour.

It is safe for you and your baby and wears off quickly.

It can be used together with other forms of natural pain relief such as a TENS machine.

Disadvantages of Entonox

It can only be used during a contraction.

Side effects include lightheadedness and nausea, which some women find so unpleasant that they have to limit the amount of gas they use.

Opioids

Opioids belong to a group of narcotics that induce sleep. The drugs used are pethidine and diamorphine, which are similar to morphine. They work by attaching themselves to opioid receptors in the brain, which block the transmission of pain.

Pethidine: This is given as an injection either in the bottom or the leg. It takes about 20 minutes to take effect and lasts for three to four hours. Unlike other opioids, pethidine sedates but doesn’t give you a pleasurable feeling of well-being. Many women strongly dislike the out-of-control feeling they experience and report not getting adequate pain relief at the peak of a contraction. It may also cause nausea and vomiting, which means an anti-nausea injection may have to be given. Pethidine can affect the baby’s breathing so should not be given in the 2 to 3 hours before birth.
Diamorphine: While pethidine is a synthetic form of morphine and is the most common medication used, diamorphine is a semi-synthetic morphine derivative and is becoming increasingly used. It not only produces better pain relief than pethidine but also gives a sense of euphoria. It causes nausea but not as much as pethidine. Like pethidine, diamorphine crosses the placenta and can cause breathing problems for the baby so its administration needs to be timed carefully.

Advantages of opioids

They help you to relax during labour.

A doctor can give you a prescription at around 36 weeks so it can be administered by a midwife at a home birth.

Diamorphine produces a feeling of euphoria, which many women find helpful during labour.

Disadvantages of opioids

Many women report that opioids make them feel nauseous. Pethidine in particular can cause nausea and vomiting.

Opioids can cause wooziness which can be disorientating during labour.

With pethidine, some women say that they feel out of control and unable to stay present with labour.

Both pethidine and diamorphine cross the placenta and pass into the baby’s bloodstream. This not only sedates your baby but also causes them breathing problems. It’s therefore very important that opioids are not given too near the time of the delivery of the baby.

Opioids can affect the mother’s breathing during labour, especially if they have a preexisting respiratory illness such as asthma or emphysema.

The use of opioids can cause chronic constipation.

Which medications are available for me for pain relief during labour?

Unii’s Giving Birth Journey explores using Entonox and opioids during labour.