This is the measurement of fetal heart rate by external monitoring. It provides a means for the surveillance the fetus in high risk conditions: prior stillbirth; maternal insulin dependent diabetes, hypertension, renal disease and collagen vascular diseases; rupture of membranes over 24 hours, preeclampsia, discordant twins, intrauterine growth retardation, postdates (overdue) exceeding 10 days; decreased amniotic fluid volume. Results: REACTIVE: during 20 minutes, there are 2 episodes of increases in fetal heart rate, each at least 15 beats/minutes above the baseline and lasting at least 15 seconds. NON-REACTIVE: if fewer than 2 episodes of increases in fetal heart rate as described above.