Pethidine, diamorphine, meptid and remifentanil might sound like the Four Horsewomen of the Apocalypse but, for some women, they are knights in shining armour. All four drugs are opioids, and they work, not by actually numbing any of your pain receptors, but simply by making you feel ‘out of it’ so that you don’t experience the pain in the same way. Pethidine, diamorphine and meptid are administered via injection in the thigh, and in some cases can be prescribed in advance for a home birth. Remifentanil comes via an infusion that can only be given by an anaesthetist, so you can’t have it at home or in a midwife-led unit. One advantage of opioids is that you can get some rest if your labour is long, but be aware that all cross the placenta and, the nearer to delivery you are given them, the more likely you are to notice an effect in your baby – he may be drowsy, slower to breathe, and breastfeeding may be harder to establish.