The influence of maternal analgesia on neonatal behaviour: I. Pethidine.

Neonatal behaviour in a group of infants whose mothers received pethidine during labour was assessed at delivery and during the first six weeks of life by means of the Brazelton Neonatal Behavioural Assessment Scale. The influence of the total maternal dose of pethidine and umbilical cord blood concentration of the drug on such behaviour has been examined with the confounding effects of all other variables controlled. Higher cord blood levels of pethidine were associated with babies who were more prone to respiratory difficulties, drowsy and unresponsive immediately after delivery. Throughout the six weeks in which the assessments were made, depressed attention and social responsiveness were found in infants with high drug levels. At three and six weeks, the infant whose exposure ao pethidine had been high tended to change state more frequently, to cry during the test and to be less capable of quieting himself. These findings suggest that the newborn infant responds to pethidine in the same way as the adult, but the changes observed were relatively subtle, and comparison of these infants with a control groups whose mothers had received no drugs revealed no between-group differences in behaviour.