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One of the biggest worries facing all mothers as the due date for the birth of the baby approaches, is the pain from the labour process. After all, it has been reported that most women experience significant pain during labour and childbirth.
What causes labour pain?
In the first stage of labour, the pain is caused by the regular contraction and stretching of the womb and cervix that serves to open the cervix. This stage may last from 8 to 12 hours for first-time mothers. The second stage of labour begins when the baby descends through the birth canal, aided by the mother’s pushing. Labour pain is not constant, but increases in intensity and frequency with the progress of labour.
Different women perceive labour pain differently. This perception may be influenced by the woman’s previous labour experience, duration of the labour and the use of drugs to accelerate the progress of labour.
What are my options for labour pain relief ?
Childbirth is not a test of endurance. In the age of modern medicine, there are now effective methods for the management of labour pain. Ideally, mothers should seek information regarding these options in the weeks or months before the due date, to allow time for informed decision-making.
Non-pharmacological methods (i.e. not using drugs)
Examples include hypnosis, hydrotherapy, local heat or cold application, transcutaneous electrical nerve stimulation (also called ‘TENS’), acupuncture techniques.
These methods vary in their effectiveness but the majority of them have not been proven, by studies, to be effective. Some of these methods may be useful in short labours. Locally, these methods have not been widely used.
Pharmacological methods (i.e. using drugs)
Examples include inhalation of entonox gas, injection of opioids, epidural or combined spinal-epidural analgesia. 
Entonox inhalation
In this method, the mother inhales a gas mixture of 50 per cent nitrous oxide in oxygen, administered via a tight-fitting face mask or mouthpiece. For effective use, the mother should start breathing the gas as soon as the contractions begin so that maximal effect is achieved at the peak of the contractions. Entonox inhalation does not eliminate pain but merely alters the mental state so that the pain is felt less acutely.
The effectiveness of entonox in the relief of labour pains varies from individual to individual. In general, up to 50 per cent of labouring mums will find this a satisfactory formof pain relief.
Advantages: It is readily available, does not stay in the body system, it's easily administered.
Disadvantages: Causes drowsiness, light-headedness and sometimes nausea.
 Opioid injections
The commonest opioid used for labour pain control is pethidine. The midwife upon request usually injects it into the muscles of the thigh. Each injection takes about 15 minutes to take effect and provides two to three hours of pain relief. However, it cannot be given when the baby is about to be delivered (usually at least four hours before delivery and is limited to situations when the cervix is < 6cm dilated), as it can cause drowsiness and breathing problems in the newborn. If these occur, an antidote known as naloxone has to be administered to the baby to reverse the side effects.
In some obstetric units, devices are available that allow the mother to self-administer short-acting opioid medication into the bloodstream intravenously by pressing a button (a technique known as ‘Patient-Controlled Intravenous Analgesia’ or PCIA). This is particularly useful as an alternative for pain relief in situations when epidural analgesia cannot be administered, such as in mothers with bleeding tendencies or spinal problems (refer below).
Whether injected into the muscles or the bloodstream, the known side effects of opioids for the mother include drowsiness, nausea and vomiting. The mother may also have shallower and slower breathing.
Epidural analgesia (EA)
Epidural analgesia (EA) is one of the most reliable and effective ways to relieve labour pain. Pain relief is achieved by the injection of local anaesthetic drugs, through a small tube, into the epidural space within the backbone canal.
The Combined Spinal-Epidural Analgesia (CSEA) differs from EA in that an initial dose of drug is injected into the spinal space, which is also within the backbone canal. This results in a faster onset of pain relief. The choice of EA or CSEA is usually left to the discretion of the anaesthetist, as dictated by the stage and progress of labour.
Possible positioning for administering epidural:
 Although EA/CSEA reduce labour pain to a great extent, some degree of pain may still be felt, especially at the time of “pushing” of the baby.
Other benefits of EA/CSEA
EA/CSEA can also help in the control of blood pressure of pregnant women with high blood pressure – a condition called “pregnancy-induced hypertension”. As such, they can prevent the blood pressure from reaching critically high levels during labour.
Patient-Controlled Epidural Analgesia (PCEA)
Some tertiary obstetric hospitals like KK hospital now offer a technique known as ‘Patient-Controlled Epidural Analgesia’ or PCEA, wherein a pre-programmed device allows the mother to administer additional drugs into the epidural space by the push of a button. PCEA has greater advantages over conventional EA/CSEA in that the mother has better control over her pain and also consumes fewer drugs during labour.
Conclusion
With so many options available, no mother should suffer from the pain of childbirth. Labour and childbirth should be a meaningful and enjoyable experience for all mothers (and fathers too)!
Myths associated with epidural analgesia
1. “There are many side effects associated with epidural usage.”
Some minor side effects, which are transient and self limiting, include:
· Loss of feeling and muscle weakness
Numbness of the legs and lower part of the body is to be expected. The urge to pass urine may also be lost, but this can be rectified by intermittent drainage of the urine by the midwife. As the epidural drug effect wears out, the sensation and strength of the legs and lower body are restored.
· Nausea
This may result from a lowering of the mother’s blood pressure or be a direct effect of the epidural drugs used. It may be treated with proper positioning and pressure-boosting medicines.
· Shivering
This may occur although the woman may not actually feel cold. Harmless to mother and baby, it usually does not require any treatment.
· Itch
Mild itch on the body is more common after CSEA than EA. Usually self-limiting, it does not need any treatment.
· Spinal headache
There is a risk of a spinal headache of about 1 per cent after EA/CSEA. The headache usually occurs after delivery and is worsened by the upright posture. Medications and a procedure called epidural “blood patch” can be used to treat the headache, if severe. In most cases, the headache resolves with time.
2. “Epidural causes long term backache.”
Studies have failed to establish a link between long-term backache and EA/CSEA. Backache is common after childbirth, with or without the use of EA/CSEA. Proper back care during pregnancy and after childbirth is important.
3. “Epidural harms the baby.”
EA/CSEA do not harm the baby. However, some temporary change in the baby’s heartbeat may occur. There is evidence that EA/CSEA may improve blood flow to the placenta and baby.
4. “Epidural can cause paralysis.”
This is actually very rare. The risk of permanent damage is actually 1 in 50,000 – 100,000. The risk of paralysis is 1 in 1,000,000.
5. “Epidural can be life threatening.”
This condition, which can involve breathing difficulty, convulsions, nerve damage and spinal infection, is actually very rare. High standards of medical practice and proper patient selection have contributed to the safety of these procedures.
6. “Epidural prolongs the labour and increases the risk of a Cesarean section.”
EA/CSEA do not result in a greater risk of Caesarean section for the mother. There may, however, be a slightly increased risk of instrumental delivery with the use of EA/CSEA, although this is not conclusively proven by studies. The benefits of EA/CSEA do outweigh the possible side effects associated with them.
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