Pain Relief in Labour

Labour pain is crampy pelvic and abdominal pain that comes and goes. Women feel their labour pain in different ways. The most common labour pain would be period pain in the pelvis, back or legs that is fluctuating in intensity. Some women will have additional pelvic pain like before a bout of diarrhoea. Others will also have abdominal muscle pain like a stitch. Labour pain increases with contractions and eases off in between which means that a woman only needs to cope with each contraction one at a time.

In the very early stages of labour it is best to rest as much as possible. A hot pack placed on the suprapubic region or lower back may allow rest in bed. Mood lighting, aromatherapy, or favourite music may be relaxing. Distraction with simple tasks, watching DVDs or playing computer games may help. Oral Paracetamol may be helpful at this early stage.

Distraction Techniques

Some women are able to focus on their breathing and induce self-hypnosis so they achieve an out-of-body experience that allows them to be emotionally isolated from any pain. Very highly motivated women can mimic this state during labour by rehearsing meditation and breathing prior to labour. For most women this technique is difficult to sustain effectively.

Distraction techniques can be useful. Self-help books, such as Juju Sundin's Birth Skills (with Sarah Murdoch), provide lots of techniques for helping with each contraction. This can include rocking, stamping, tapping, squeezing, vocalisation and visualization. These simple skills can be used without practising them before labour and may be interspersed with breathing and meditation.

Hot water and TENS machine

 Hot water applied to the skin in the bath, shower or as hot packs, can irritate the nerves of the skin to distract from the deeper pain. A TENS Machine (that can be hired from the Physiotherapy department) applies an electrical current to the nerves of the skin which distracts from deeper pain.

Sterile Water Injection

If there is severe back pain during labour but the abdominal pain is manageable, then injections of sterile water into the lower back can irritate the nerves and distract from deeper back pain.

Pushing as a distraction

At fully dilated and when it is time for pushing, focusing on the act of pushing can distract from contraction pain. Pushing requires some co-ordination with engagement of the abdominal muscles usually used for evacuating bowel motions. When the contraction builds up a breath is taken and the muscles are used to push down for as long and hard as possible toward the bottom. The breath is exhaled, and a new breath taken, then this is repeated again. We aim for three pushes during each contraction.

Pushing is more efficient when the breath is held and this is different from the rest of labour. Women who have been focusing on their breathing may find it hard to change to active pushing. Very few babies can be breathed out and most vaginal deliveries will require expulsive effort by the woman, whether there is a strong urge to push or not.

The Birth Skills book has a useful chapter on the coffee plunger imagery of pushing. The held breath at the bottom of the lungs pushes the diaphragm down and this forms the coffee plunger. This helps put pressure on the abdominal muscles, on the uterus and on baby and helps channel the expulsive effort downward. The coffee plunger image may make the transition to pushing more effective.

Other Options

Once regular contractions have established, the blood supply is diverted to the uterus and the bowel comes to a complete stop. Oral analgesia will not be absorbed. Other options for pain relief are Nitrous gas, Morphine injection or Epidural.

Nitrous Gas

Breathing Nitrous gas can make contractions more tolerable and it can be made available within a few minutes. For Nitrous gas to be effective, breathing of the Nitrous must commence at the very beginning of the contraction so that the Nitrous levels are highest during the peak of the contraction. Some women can use Nitrous gas for many hours and it works well for them. Most women can only sustain breathing Nitrous for a short time as they get a dry mouth, nausea and light-headedness.

Narcotic Injection

Morphine (and sometimes Pethidine) is a Narcotic given as an injection. It takes about 5 minutes to get ready and another 20 minutes before it has an effect. Morphine does not take the pain away but will decrease the perceived intensity and make women less anxious about what they are feeling.

 In the hours following administration of Morphine there may be a small window of peak levels in the maternal and fetal circulation. If baby is born during this window they can be slow to breathe and require an injection to reverse the effect of the Morphine. This is not a very common occurrence.

Morphine tends to be used early in the labour process when contractions are occurring but the cervix is not very dilated. Morphine at this stage can encourage resting. Morphine is also used when labour is progressing quickly and there isn't time, availability or preference for an epidural.

Epidural

An epidural that is working effectively will take away all labour pain. A well-managed epidural will not change the outcome of labour. Epidurals are very common at Mater Mothers’ Hospital (over 80% of women having their first baby, privately and publicly) will have an epidural) and they are very well-managed. Once an epidural is requested, it takes anywhere from five minutes to an hour for an anaesthetist to attend and then another 20 minutes for it to become effective.

Intravenous fluid is required to compensate for any blood pressure lowering effect of the epidural. For epidural insertion, local anaesthetic is placed in the skin and a needle is inserted between the vertebra. Fluid is used to allow very fine tubing to be threaded through the needle into the epidural space adjacent to the spinal fluid. A mixture of anaesthetic and narcotic is infused through the tubing so that pain will be relieved in the lower half of the body. Current anaesthetics have more effect on sensory nerves than motor nerves so it is possible to move the legs around the bed without feeling abdominal pain and most women can push effectively.

An epidural is medically recommended when someone has high blood pressure in labour. Medication that can lower blood pressure may reduce the blood supply to the placenta. An epidural will lower blood pressure without decreasing blood supply to the placenta so it is the safest way to lower blood pressure during labour.

An epidural is recommended if a woman has an early urge to push. If there is cervix in front of baby’s head, then pushing will make the cervix swollen and this may slow the progress of labour. An epidural can take away the urge to push until the cervix is fully dilated and the head is well down. This can reduce the time of active pushing.

An epidural is useful if there is fatigue during labour. Some women may have been uncomfortable and not slept well for days before labour or a long first labour may be exhausting. Pushing requires a 100% effort to be effective so having an epidural can provide an opportunity to rest during labour and conserve energy for pushing.

After having an epidural, a catheter will be inserted into the bladder as the sensation of the bladder filling will be lost. This catheter will be removed at least 12 hours after delivery when the effect of the epidural has fully worn off. Keeping the bladder empty can reduce the risk of a heavy bleeding after baby is born as a full bladder can prevent the uterus from contracting down on the placental bed.

If a group of low risk women have epidurals in labour, the outcomes (normal delivery, Caesarean section, vacuum or forceps) are not statistically different from those who don’t have epidurals. Care must be taken to titrate intravenous fluids to avoid maternal low blood pressure which might cause fetal distress. If the contractions are not strong enough after an epidural then intravenous Syntocinon can be used to improve the contractions and reduce the chance of cervical dilatation not progressing. Women can be coached to push effectively without feeling a strong urge to push. An epidural may not relieve the feeling of pressure on the back passage and this sensation can be used to guide pushing.

If a Caesarean section is required, for non-reassuring fetal wellbeing or inadequate progress of cervical dilation, then the epidural can be topped up to prevent pain during this procedure. If there is not a working epidural in place then spinal anaesthetic may be sited or the procedure may be performed under general anaesthetic.

 

Resource Book.

Sundin, Juju. (with contribution from Murdoch, Sarah). Birth Skills: proven pain-management for your labour