Epidural for childbirth

Published by Bupa's Health Information Team, June 2010.

This factsheet is for women who are having an epidural during childbirth, or for people who would like information about it.

An epidural stops women feeling pain during childbirth without putting them to sleep.

You will meet the anaesthetist carrying out your epidural to discuss your care. It may differ from what is described here as it will be designed to meet your individual needs.

How an epidural is given during childbirth

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About epidural in childbirth

An epidural stops you feeling pain without putting you to sleep. It can be used to provide pain relief during childbirth and can also be adapted to provide pain relief during a caesarean.

An epidural involves local anaesthetic and sometimes other pain-relieving medicines as well, being injected into your lower back, just above your waist. After an epidural, you shouldn't be able to feel any pain in your abdomen (tummy) or the tops of your legs.

Epidurals are usually very effective, but take about 30 minutes to work. If you have an epidural, your second stage of labour may take longer because you won't feel the urge to push. It may also make moving around more difficult because you will have less feeling in your back and legs and you may find it difficult to move your muscles.

An epidural isn't suitable for you if you have a blood-clotting problem. You must tell your midwife or anaesthetist if you're taking blood-thinning medicines such as aspirin, warfarin or clopidogrel. An epidural may not be suitable for you if you have had an operation on your back. Ask your midwife or anaesthetist for more information.

How does an epidural work?

Your spinal cord runs through a channel formed by your vertebrae (irregular-shaped bones in your spine) and is surrounded by three protective layers of tissue called the meninges. A protective layer of fluid lies between two of these tissue layers (this is known as the cerebrospinal fluid or CSF). The area just outside all these layers is called the epidural space.

Your spinal cord carries signals, in the form of electrical impulses, between your brain and the network of nerves that branch outwards from your spine to all parts of your body. At each level of your spine, nerves leave your spinal cord to go to specific parts of your body. For example, nerves from the lower part of your body join your spinal cord in your lower back.

The epidural space in your lower back is where your anaesthetist will inject the local anaesthetic. This blocks the nerves in your spine that lead to the lower part of your body, stopping you feeling pain. Your anaesthetist can control how much feeling is lost, depending on the amount and type of medicines used. A caesarean may be done with an epidural, without the need for you to have a general anaesthetic.

What are the alternatives?

There are several other methods of pain relief you can try if you don't wish to have an epidural. Talk to your midwife about the risks and benefits of these.

• Gas and air. This is a mixture of nitrous oxide and oxygen and is a mild painkiller. As you feel a contraction starting, you breathe the mixture in through a mouthpiece or a mask placed over your nose. It will probably make your contractions less painful, although not all women find it effective.
• Opiate medicines. These medicines include diamorphine, morphine and pethidine. They are very effective at relieving pain, but can make you feel sick or dizzy. Opiate medicines can also make your baby feel sleepy and can sometimes temporarily reduce your baby's ability to breathe at birth.
• Transcutaneous electrical nerve stimulation (TENS). Two electrodes are placed on your back and electrical impulses are sent to your nerves to block the perception of pain going from your uterus (womb) to your brain. TENS is often used early in labour and may become less effective as labour progresses.

Preparing for an epidural

Your anaesthetist will discuss with you what will happen before, during and after your epidural, and any pain you might have. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

What happens during an epidural

You will be asked either to lie on your side, with your knees drawn up to your tummy and your chin tucked in, or to sit up on the bed and lean forward. Both positions open up the space between your vertebrae.

Where the epidural is positioned

Your anaesthetist will carefully select a point to inject by feeling for specific bones in your spine and hips. He or she may mark this site with a pen to show where to insert the needle. Your anaesthetist will give you an injection of local anaesthetic in this area to numb your skin and tissues.

When your skin is numb, your anaesthetist will pass a larger needle into the epidural space. When the needle reaches the correct spot, he or she will insert a fine plastic tube (cannula) through the centre of the needle. Your anaesthetist will then remove the needle and leave the cannula in place, running from the epidural space to outside of your body.

The cannula is held in place with adhesive tape. Your anaesthetist will use the cannula to inject local anaesthetic and/or other pain-relief medicines directly into the epidural space. Your anaesthetist may attach a pump to the cannula so that you can have a top-up as and when you need it. You may be allowed to control the pump yourself. This is called patient-controlled analgesia or PCA.

It's very important to stay still while your anaesthetist is preparing the site for the epidural injection and especially while the epidural needle is being inserted. Any movement makes positioning the needle more difficult.

When you no longer need any pain relief, the cannula is carefully withdrawn and the area is covered with a plaster.

What to expect afterwards

After an epidural you will need to rest until the effects of the anaesthetic have passed. You may not be able to feel or move your legs for several hours.

What are the risks?

Epidurals are commonly performed and generally safe. However, in order to make an informed decision and give your consent, you need to be aware of the possible side-effects and the risk of complications of this procedure.

Side-effects

These are the unwanted, but mostly temporary effects of a successful epidural. Common side-effects are listed here.

• Backache. The epidural relaxes your back muscles and because of this you may develop back pain after giving birth. You're more likely to develop backache if you had back pain before or during your pregnancy. The pain should improve with time.
• A drop in blood pressure. Your blood pressure will be checked regularly. If it drops, you may be given medicines to correct it.
• Loss of strength or control of your leg muscles. Your muscle strength will return with time after the epidural has been stopped.
• Difficulty passing urine. You may need to have a catheter fitted to drain urine from your bladder into a bag, until the effects of the epidural wear off.
• Itchy skin. This may happen with some medicines and your anaesthetist will change your medicine to deal with this.

Complications

This is when problems occur during or after the epidural. Most women aren't affected. With any procedure involving anaesthesia there is a very small risk of an unexpected reaction to the anaesthetic. Complications specific to epidural are uncommon but can include the following.

• Headache. The epidural may puncture the membrane covering your spinal cord and fluid can leak out. This is called a dural puncture and it can cause headaches. Headaches can last up to a week, sometimes longer, and if they are severe you may need further treatment. You may need an epidural blood patch, which means that some of your blood is taken and injected near to the puncture where it will clot and seal the hole.
• Assisted birth. You may find it difficult to push. It's possible that your midwife or doctor may need to use forceps, a ventouse (vacuum extraction) or some similar assistance to help you give birth.
• Infection. This is rare because your skin is cleaned before the (sterile) needle is inserted. If you develop an infection, the cannula may need to be removed, the infected area may need to be drained and you may need to take antibiotics. If you develop a fever after you have returned home, contact the hospital or your GP for advice, as you may have an infection.
• Long-term numbness. You may have temporary patches of numbness. Permanent damage, such as paralysis (complete loss of sensation and movement), is extremely rare.

The exact risks are specific to you and differ for everyone, so we have not included statistics here. Ask your anaesthetist to explain how these risks apply to you.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.