There is a definite increase in the number of cases in which it is helpful to know about the fetal heart rate. These are: intra-uterine growth retardation whether associated with hypertension or not, or whether the patients have lost a fetus in utero before. In these cases it is necessary to hospitalize the patient for a long time or make them come to the clinic very often. Watching these patients at home (using either midwifery or hospital staff) is often difficult, so it seemed useful to us to develop another system of monitoring these patients at home. We have been testing, for the last year and a half, a simple system of recording the fetal heart rhythm that can be used by the patient herself at home. The recordings are transmitted daily or twice daily by telephone. The midwife in the maternity unit can look at the tracing and ask the patient to come if the tracing is insufficient or suspicious. We present here the results of 816 tracings carried out in 402 patients: --the tracings correspond completely to those taken at the same time by the usual machines as far as the fetal ECG is concerned. Their interpretation does not give rise to any problems as compared with those of usual tracings. --about 80% of the tracings could be interpreted. They vary according to how far on the pregnancy has progressed (73% at 32 weeks of pregnancy and 84% at term). Telephone transmission was carried out in 84% of cases. Isolated monitoring of fetal heart rhythm (without recording tracings of uterine contractions) makes it possible to monitor these patients at risk of having chronic fetal distress.