Oxytocin challenge test and intrauterine growth retardation.

On the basis of analyses of the nonstressed fetal heart rate test (NST) and the oxytocin challenge test (OCT) in 85 fetuses with intrauterine growth retardation (IUGR), the predictive power of NST/OCT on fetal outcome and the mechanism of a positive OCT in IUGR were investigated. These fetuses with IUGR exhibited high incidences of nonreactive NSTs (35.3%) and positive OCTs (40%) attributable to a combination of compromised placental function and diminished fetal reserve. Adverse fetal prognosis is most accurately predicted by the joint occurrence of a nonreactive NST and a positive OCT (92%). In such cases, when IUGR is strongly suspected, liberal use of cesarean section is recommended to assure good fetal outcome.