Continuous twenty-four hour recording of the fetal cardiac rhythm during normal pregnancies

Recording the fetal cardiac rhythm (FCR) is currently the technique most widely used to assess the well being of the fetus. In view of the importance of the decisions taken on the modifications of the FCR, the authors have recorded and analysed over 24 consecutive hours 10 resting women manifesting a strictly normal pregnancy. They observed no modification in the basal cardiac frequency, very few declarations and above all, never any signs of a flat or sinusoidal rhythm. Flattening of the FCR is invariably pathological. It must not be interpreted as "fetal sleep" period, but it should intensify the surveillance.