Pain relief with medicine

Choosing medicine for labour pain is not giving up, and going without it is not a test of strength. This chapter explains each option so you can decide, and change your mind, with good information. Medicine works well alongside the comfort measures in "Coping with pain without medicine". Not every birth place offers every option, and epidurals are not available at home or in most freestanding birth centres, so ask before labour. Nitrous oxide (gas and air)

Nitrous oxide is a mix of half nitrous oxide and half oxygen that you breathe through a mouthpiece or mask you hold yourself. It takes the edge off contractions rather than removing the pain.

It takes about 20 to 30 seconds to work, so start breathing it slowly and deeply as a contraction begins, and stop as it fades. It wears off within a minute or two, leaves your body through your lungs and does not build up in your baby.

It can make you light-headed, nauseated or a little detached. Because you hold the mouthpiece yourself, you cannot take too much: if you become drowsy, your hand drops away. You can stay mobile and use it for stitches afterwards.

Opioids: injections and pumps

Opioids are strong pain medicines. In labour they are given as an injection into a muscle (often the thigh or buttock) or through an IV line. Which one you are offered depends on where you are. They work within about 10 to 20 minutes for an injection, faster through a vein, and last a few hours. Opioids dull pain and help you relax or doze between contractions, which can be a gift in a long early labour, but they rarely remove the pain. Common side effects are drowsiness, nausea and vomiting, itching and feeling out of control.

Opioids cross the placenta. If given within a few hours of the birth, your baby may be sleepy, slower to breathe at first and slower to start feeding. Your team keeps this in mind when timing doses.

Some hospitals offer patient-controlled analgesia (PCA), often with a short-acting opioid such as remifentanil or fentanyl. A pump connected to your IV line gives a small, preset dose when you press a button, with a lockout so you cannot have too much. Because it can slow your breathing, you will be watched closely with a clip on your finger measuring oxygen. It is often offered to people who cannot have an epidural.

Epidural

An epidural is the most effective pain relief in labour, and most people who have one get good to complete relief. A thin, soft tube (catheter) is placed in your lower back, in the space just outside the sac of fluid around the spinal nerves. Local anesthetic, usually mixed with a small amount of opioid, flows through it and numbs the nerves carrying pain from the uterus and birth canal. It is placed by an anesthesiologist (anesthetist).

How it is placed, step by step

• 1. An IV line is put in your hand or arm, and your blood pressure is checked.
• 2. You get into position: sitting on the edge of the bed, leaning forward and curling your back like a cat or a prawn, or lying curled on your side.
• 3. Your back is cleaned with a cold antiseptic and covered with a sterile drape.
• 4. A local anesthetic is injected into the skin to numb it. It stings for a few seconds.
• 5. The epidural needle goes in through the numb skin. You will feel pushing and pressure but not usually pain. Stay as still as you can, and say when a contraction is starting so they can pause.
• 6. The catheter is threaded through the needle, and the needle is removed, leaving only the soft tube. You might feel a brief tingle or zing down one leg as it goes in; this is normal and passes.
• 7. The tube is taped up your back and over your shoulder. A test dose is given, then the full dose.

Placing it usually takes about 10 to 20 minutes, and it starts working over the next 10 to 20 minutes, with full effect in about half an hour.

What it feels like

Your belly and legs feel warm, heavy and tingly, then numb. Many people still feel pressure with contractions, without pain. Your baby's heart rate is usually monitored continuously and your blood pressure checked often. If it works on one side only or leaves a painful patch, tell your team: changing position, adjusting the tube or a top-up often fixes it.

Low-dose and "mobile" epidurals and top-ups

Modern epidurals use less local anesthetic than in the past, keeping some strength in your legs so you can shift position, kneel on the bed and sometimes stand beside it with help.

Once it is in, the epidural is kept going by a pump giving a steady flow or regular automatic doses, often with a button you can press for an extra dose (patient-controlled epidural). A stronger top-up can be given for an assisted birth, stitches or a caesarean.

Effects on labour and pushing

An epidural does not raise the chance of a caesarean. It is linked to a longer second stage, by perhaps half an hour to an hour on average, and to a somewhat higher chance of an assisted birth with forceps or vacuum, though this is less clear with modern low-dose epidurals. You may not feel a strong urge to push. Waiting an hour or so after full dilation for your baby to move down on their own ("labouring down"), changing positions with a peanut ball, and being coached through each push all help. You may also need an oxytocin drip if contractions slow.

Side effects and rare risks

Common or fairly common:

Low blood pressure, which can make you feel faint or sick and affect your baby's heart rate. Fluids and medicines treat it quickly.

Itching, from the opioid in the mix. It usually settles or can be treated. Difficulty peeing, so you may need a catheter in your bladder during labour.

A rise in temperature, which can lead to tests or antibiotics to be safe. Less common or rare:

A severe headache (about 1 in 100 to 1 in 200), when the needle nicks the sac of fluid. It is worse sitting up and better lying flat. It can be treated, if needed with a "blood patch", in which a little of your own blood is injected near the site to seal the leak.

Not enough pain relief, needing the epidural to be redone, in roughly 1 in 8.

Temporary nerve damage, such as a numb patch or weak leg, in about 1 in 1,000; most resolves within weeks or months. Long-term nerve damage is very rare.

Infection, bleeding or other serious complications around the spine are very rare.

An epidural does not cause long-term back pain. You may have a tender spot where it went in for a few days.

Who may not be able to have one

An epidural may not be possible or safe if you have a bleeding or clotting problem, a low platelet count, take blood-thinning medicines (timing matters), have an infection in your back or a serious infection in your blood, or have certain spine conditions or previous spinal surgery. If any of these apply, ask for a meeting with an anesthesiologist during pregnancy to plan ahead.

Timing myths

"It is too early." There is no dilation at which you must wait. If labour is established and you want an epidural, you can have one.

"It is too late." It can be placed in active labour, even late, as long as you can stay still long enough. It may not be possible if the birth is only minutes away, because it would not work in time.

Spinal and combined spinal-epidural

A spinal is a single injection of anesthetic into the fluid around the spinal nerves, using a very fine needle. It works within about five minutes and gives dense numbness for one to two hours. There is no tube, so it cannot be topped up. It is the most common anesthetic for a caesarean (see "Caesarean birth") and is also used for some assisted births and repairs in the operating room.

A combined spinal-epidural (CSE) gives a small spinal dose for fast relief and places an epidural tube at the same time for ongoing relief. It is useful when labour is moving quickly or pain is very intense.

Pudendal block and local anesthetic

A pudendal block numbs the pudendal nerves, which carry feeling from the vagina, vulva and perineum. A doctor injects local anesthetic through the vaginal wall on each side. It works in a few minutes and is sometimes used for a forceps or vacuum birth if you have no epidural. It does not help with contraction pain.

Local anesthetic injected into the perineum numbs it for an episiotomy (see "When labour needs help") or for stitches after birth.

Cse

In your birth preferences, describe your wishes rather than make promises to yourself: for example, "I would like to start with movement and water; please don't offer an epidural, but I will ask if I want one." Or: "I would like an epidural as soon as I am in established labour."

Agree on a code word with your support person that means "I really want pain relief now", so they can tell it apart from an ordinary "I can't do this". Ask in advance how long the wait for an anesthesiologist tends to be.

Changing your mind

You can change your mind at any point, in either direction. You might plan an epidural and find water and support are enough, or plan to go without and find a long labour makes medicine the right choice. Neither is a failure. How you feel about your birth depends far more on feeling informed and listened to than on which pain relief you used.

In short

Nitrous oxide takes the edge off within seconds and wears off within minutes.

Opioids help you rest but can make you and your baby drowsy if given close to birth.

An epidural is the most effective option; it takes around half an hour to work, does not raise the chance of a caesarean, and may lengthen pushing.

Spinals work in minutes and are used mainly for caesareans; pudendal blocks and local anesthetic numb the birth canal and perineum.

Write flexible birth preferences, agree on a code word, and feel free to change your mind.