“1.4. Certain patterns of electronically monitored FHR recordings are strongly associated with specific changes in fetal condition. However, not infrequently uncertainty exists in respect to interpretation. Unnecessary operative interventions might be the result of incorrect interpretation and overestimation of the diagnostic potential of electronic FHR monitoring. Therefore it cannot be emphasized enough that understanding and interpretation of a FHR record is not an easy matter and that formal training in the underlying physiology and the practise of FHR monitoring is indispensable for all those supposed to make decisions on FHR records. Furthermore it needs to be stressed that whereas certain FHR patterns are sensitive indicators of fetal hypoxia, the specificity is low. It is rarely possible to quantitate hypoxia on the basis of FHR records alone and information derived from FHR records only represents one piece of information which always has to be interpreted in the context of the clinical situation.”
“Baseline fetal heart rate is the mean level of the fetal heart rate when this is stable, accelerations and decelerations being absent. It is determined over a time period of 5 or 10 min and expressed in beats/min (bpm). Variability. …in clinical practice variability means long term variability. .. Long term variability is characterized by the frequency and the amplitude of the oscillations. Although the frequency may be important, it is difficult to assess correctly. Therefore variability is usually only quantitated by description of the amplitude of the oscillations around the baseline heart rate. Accelerations. Transient increase in heart rate of 15 beats/min or more and lasting 15 s or more. Decelerations. Transient episodes of slowing of fetal heart rate below the baseline level of more than 15 beats/min and lasting 10 s or more.”
“If conservative measures do not succeed in correcting the fetal heart rate abnormality, then delivery or scalp pH and blood gas measurement In the present case, it is agreed between the parties that taking a fetal blood sample was not an option which fell to be considered by the clinicians. should be undertaken, the course of action determined by the severity of the abnormality and the likely proximity of delivery.”
“There is good evidence…that abnormal patterns in the preterm fetus are correlated, to a greater extent than term fetuses, with abnormal outcome.”
“The most critical feature, however, is the evolution of the trace with time. A change in the baseline rate and change in the baseline variability are the key signs of developing hypoxia and acidosis… Much time is wasted in discussion over whether decelerations are early, late or variable and whether they can be pigeon-holed into “good”, “bad” and “possibly good”