Pain Relief in Labour

Introduction

Pain is an unpleasant but most useful sensation developed early in evolution as a protective mechanism. In the context of labour, pain is a symptom of labour and alerts the mother to seek timely help for labour and delivery. The pain of labour gets progressively severe and it is often aggravated by anxiety, fear and ignorance. In a civilised society, freedom from pain is one of the basic rights of a person. This is often ignored in the developing world, when it comes to a labouring woman. The reason for this cruelty is tradition, ignorance and plain lack of resources. In the developed world, when some form of analgesia is always available, a few women are brainwashed into equating pain relief in labour with personal failure. More often than not, these women not only suffer needlessly, but also reduce their chance of a normal delivery. Unrelieved maternal pain leads to a series of metabolic changes in the mother, which may adversely affect the foetus (Jones CM, Greiss FC. 1982). 

Labour Pain 

In the first stage of labour, the pain is from uterine contractions (ischemic) and cervical dilatation (stretching).

The intensity of the pain and its extent is increased late in the first stage and early second stage. 

The site of pain shifts mainly to the vulva and perineum late in the second stage and at delivery. 

Pain Relief in Labour 

Researchers like Melzak and others, after investigating serious pain for fifteen years, reported that labour pain was the most severe pain that they assessed (Melzak R et al. 1981). Selwyn Crawford says, "Because labour pain serves no useful function in the human female (except possibly to expiate primeval feeling of guilt), a positive refusal to utilise available measures to alleviate it, borders on the unethical (Crawford JS, 1985). 

The total pain of labour is not simply the physical pain that can be explained on the basis of physiological, chemical and neurological phenomena. The level of anxiety, fear and ignorance influence labour pain as mentioned before. Melzak and others showed that mothers who entered labour with good and sympathetic childbirth preparation had a pain score 30 percent lower than those who entered labour with no such preparation (Melzak R. 1984). 

Principles of Pain Relief in Labour 

Anticipating pain and providing pain relief is much more successful than chasing after established pain. 

There are two (or more, in the case of multiple pregnancies) people in every labour - mother and baby. 

Labour pain affects the mother primarily but also affects the baby by release of the stress hormones of the mother when pain is not relieved. 

Treatment modalities also affect both mother and baby. 

An ideal analgesic in labour is one, which provides total pain relief to the mother without adversely affecting the labour process or cause unwanted side effects in the mother or baby. It should also be freely available, easy to use and cheap. Unfortunately, such an analgesic is not available at present. 

Methods of Pain Relief in Labour (not mutually exclusive) 

a) Psycho prophylaxis- prepared childbirth, breathing exercises. 

b) Environmental modifications - birthing room, support person(s), music, incense. 

c) Physical treatment - massage, heating pads, warm bath. 

d) Electrical- TENS (Transcutaneous Electrical Nerve Stimulation). 

e) Pharmacological: 

1. Intermittent inhalation of nitrous oxide and oxygen-Entonox 

2. Systemic narcotic injections-nurse or patient controlled-Demerol, Nubain and Fentanyl 

3.Regional nerve blocks-paracervical, pudendal, extra dural (lumbar epidural, caudal) and spinal.

f) Others-hypnosis, acupuncture 

(concluding part follows)