Blind oxytocin challenge test and perinatal outcome.

A total of 435 oxytocin challenge tests (OCT) were performed on 217 high-risk pregnant patients, and the test results were blinded. The results were correlated with late decelerations of the fetal heart rate during labor, Apgar scores at 5 minutes, a neonatal morbidity score, and perinatal mortality. The incidence of late decelerations during labor was 17% in the negative group, 24% in the suspicious group, and 33% in the positive group. The correlation of OCT results and the various measures of fetal outcome indicated that an individual fetus at risk cannot be identified with a high degree of accuracy since 67% of the tests were false positive and 17% were false negative. Even when the OCT was positive, 61% of infants did not have late decelerations in labor, low Apgar scores, or significant neonatal morbidity. When elective delivery has been decided upon after consideration of all clinical information, induction of labor rather than primary cesarean section is usually indicated. In this study 78% of patients were delivered vaginally with no significant increase of cesarean sections in the positive and suspicious groups as compared with the negative group.