PN is required to maintain or restore an anabolic state when oral enteral routes are not feasible. Despite 22 years of experience with PN, its use during pregnancy has only recently been reported. Most of this information is anecdotal but suggests that this mode of therapy is safe, effective, and occasionally lifesaving. PN during pregnancy has been used most often to provide adequate nutrition for those who suffer from prolonged hyperemesis or who have difficulty absorbing adequate nutrients because of such conditions as Crohn's disease. The proper selection and administration of dextrose, fat, protein, vitamins, trace elements, and electrolytes for pregnant women have been associated with favorable perinatal outcomes. Fat emulsion use does not appear to be associated with any abnormal outcomes. Preterm deliveries and intrauterine fetal growth retardation appear to relate to preexisting or coexisting medical or obstetric complications. Principles for PN with all patients would apply during pregnancy. As with any therapy, the benefits must be weighed against the risks and costs. Sufficient favorable clinical experience over the last 10 years suggests that PN is a relatively safe and effective method for reversing maternal malnutrition and promoting normal fetal growth and development.