Nitrous oxide
Description
Nitrous oxide — an odorless, tasteless gas — is an inhalation analgesia that can be used during labor. You administer the anesthetic gas using a hand-held face mask. Nitrous oxide takes effect within a minute. While common in the United Kingdom and Canada, this technique is rarely used in the United States.
Pros
Nitrous oxide alters pain perception. It can be used intermittently or continuously during labor. If you need to have a tear repaired after delivery, you might use nitrous oxide as a supplement to a local anesthetic. Self-administration might give you a sense of control over your pain management. If you become too drowsy, you'll be unable to continue holding the mask to your face and stop inhaling the anesthetic — a built-in safety mechanism. Nitrous oxide has little or no effect on the baby.
Cons
Nitrous oxide doesn't eliminate pain. You might experience dizziness, nausea and restlessness.
Gas and air (Entonox)
This is a mixture of oxygen and nitrous oxide gas. Gas and air won't remove all the pain but it can help to reduce it and make it more bearable. Many women like it because it's easy to use and they control it themselves.
How it works
You breathe in the gas and air through a mask or mouthpiece, which you hold yourself. You'll probably practise using the mask or mouthpiece if you go to an antenatal class. The gas takes about 15 to 20 seconds to work, so you breathe it in just as a contraction begins. It works best if you take slow, deep breaths.
Side effects
There are no harmful side effects for you or the baby but it can make you feel light-headed. Some women also find that it makes them feel sick, sleepy or unable to concentrate. If this happens, you can stop using it.
If gas and air doesn't give you enough pain relief, you can ask for a painkilling injection as well.
Pethidine injections
Another form of pain relief is the intramuscular injection (into the muscle of your thigh or buttock) of a drug,