The three main medical types of pain relief used in childbirth are entonox (gas and air), pethidine (or other opiate drug), and epidural anaesthesia. Non-medical methods include breathing techniques, and the TENS machine which, although they may not completely eradicate the pain, can take the edge off it. Some women combine other non-medical pain relief methods with drugs and anaesthesia.
Entonox (gas and air)
Entonox, which is nitrous oxide, a mixture of gas and oxygen, has been used during labour since the middle of the last century and is considered a very safe form of pain relief. You inhale it, slowly and deeply, through a special mask or mouthpiece. It helps to ease your perception of pain but does not remove the pain entirely. Its effect is not immediate; if inhaled at the start of a contraction, it takes effect by the time the contraction is at its peak.
Nitrous oxide is particularly useful in early labour, but can be used at any time, and in combination with other methods of pain relief It is impossible to overdose on gas and air, so you can have as much as you want, and it won't affect your baby.
Some women find that it is not really strong enough if contractions are very severe. It can also make you feel "out of it" and nauseous.
Pethidine (or other opiate drug)
Pethidine is a synthetic analgesic drug that is similar to morphine. This type of pain relief is administered by an injection into the muscle of your buttock or thigh about every three to four hours. Pethidine relieves pain by stimulating specific "opiate" receptors in your brain and spinal cord that are also the target of endorphins, your body's own painkillers.
Why choose this method? Pethidine can be an effective pain reliever; it is particularly useful when you can't have, or don't want, other forms of pain relief, such as epidural anaesthesia. What are the drawbacks? Reactions to this drug include nausea, vomiting, blurred vision, sleepiness, and mood changes. If you are given pethidine within the two hours prior to your baby's birth, it can make your baby sleepy and affect his or her ability to breathe and move spontaneously or to respond to stimuli. For these reasons, pethidine should not be given too late in labour.