Fetal growth retardation following maternal morphine administration: nutritional or drug effect?

The effects of maternal morphine administration on maternal nutrition and on fetal growth have been systematically examined in a rabbit model. Significant alterations in maternal food intake occurred morphine exposure. These nutrition changes did not result in fetal growth retardation. Fetal morphine exposure was associated with significant reductions in fetal weight, length, placental weight and in the weights of most organs including the brain. When organ weight was considered as a fraction of total fetal weight morphine exposure was associated with a significant increase in the relative weight of the brain and a significant decrease in the relative weight of liver and kidneys. These narcotic effects were dose dependent.