I understand there is evidence of increased drug abuse in adults of which were born to mothers who utilized some form of pharmacological pain relief during labor.  Is anyone able to direct me to this research please? 

Bricker L, Lavender T. Parenteral opioids for labor pain relief: a systematic review. Am J Obstet Gynecol 2002;186(5 Suppl Nature):S94-109.

This systematic review includes studies reporting that babies born to mothers who used opioids in labor were more likely to be addicted to narcotics or amphetamines as adults. The source citation will lead you to the specific study or studies looking at this outcome. (A systematic review is itself a kind of scientific study in that it has rules for its proper conduct, but instead of studying some issue, it "studies studies" on a particular issue.)

-- Henci