Pharmacological analgesia given to a mother during labour may affect the fetus and newborn in a number of ways. Firstly a drug may cross the placenta and exert a direct effect on the baby. Secondly a method of analgesia may alter maternal physiology or biochemistry and in so doing it may have an indirect effect on the baby. Thirdly it may affect the interaction between mother and baby after delivery. This latter aspect is rather the province of the psychologists. The effects on the baby of different methods of anaesthesia for operative delivery are well researched but are more exclusively the responsibility of anaesthetists and therefore of less import to obstetricians than is analgesia. These will be discussed only insofar as research findings may also be applicable to analgesic methods.