The nonstress test. A preliminary report of a graded classification

A series of 1,504 antenatal fetal heart rate studies (nonstress tests) in 525 high-risk patients was performed. Accelerations with fetal activity are important. A graded classification of heart rate reactivity was used. There were no antenatal fetal deaths with a reactive pattern. In addition, there was an increasing incidence of intrapartum fetal distress with decreasing fetal cardiac reactivity.