Doppler flow velocimetry was performed on 273 nonselected patients in labor. All patients were at least 2 cm dilated and 80% effaced (58% greater than 4 cm) and were delivered of infants within 24 hours. Fetal heart rate tracing performed at the same time was read by another observer and compared with Doppler flow velocity measurements (systolic/diastolic ratio, pulsatility index). A significant correlation was noted (r = 0.234, p less than 0.001) between the two modalities. Both fetal heart rate tracings and umbilical flow velocity measurements were correlated with fetal outcome. Significant associations were noted between the umbilical systolic/diastolic ratio and fetal distress. 5-minute Apgar scores, the need for intubation independent of gestational age, and umbilical arterial cord pH and base excess. It appears that the information obtained from flow velocimetry had additional benefits compared with that of fetal heart rate tracings alone.