RE: pethidine...

The pain team at the hospital I work at has completely stopped using pethidine, and removed it from all wards. They have a limited supply for those obstetricians that insist on using it, but even that is locked away. The problem with pethidine is that the by-product of the drug when it is broken down in the body (a substance called norpethidine) can build up and cause lots of problems, including convulsions (fits). A lot of hospitals are phasing it out in favour of morphine (or fentanyl, for people who are allergic or have other reactions to morphine). Of course, none of the opioid-type drugs (morphine, pethidine, fentanyl, hydromorphone) are good for the baby - they all cross the placenta and will all sedate the baby if they are given during labour.

For more info, the TGA highlighted the problems associated with using pethidine as far back as 1997: http://www.tga.gov.au/docs/html/aadrbltn/aadr9708.htm (part way down the page).

If you feel you need an opioid drug to assist with pain relief, I'd suggest asking for something other than pethidine.