Jonathan, The mothers in the Rigard study were given pethidine (Demerol or meperdine). I think it was given I.M. or I.V. It is my understanding that dosages are much smaller and systemic absorption much less with epidural administration. I am all for natural birth, but if moms need or want medication, I would like to promote that which interferes the least. Thanks for taking the time to respond, and please correct me if I am wrong. Bonnie Jones, RN, ICCE, IBCLC