The relevance of antenatal and intrapartum fetal heart rate patterns to fetal outcome.

Antenatal fetal heart rate (FHR) as an indicator of fetal status was evaluated in two separate studies. The first attempted to determine, in 30 minutes of continuous recording from each of 50 antenatal patients, relationships between spontaneous FHR changes and fetal condition before and after birth. No significant association was found between observed FHR patterns and antenatal or neonatal fetal status. The second study used induction of labour as a stress test, because similar conditions to that required for oxytocin stress testing were present and there was the advantage of direct FHR recording. In 150 induced and monitored labours, FHR changes associated with the first six suitable contractions seldom related to Apgar scores at birth or development of fetal distress in active labour. Fetuses showing no response to contractions tended to have better Apgar scores than those which showed FHR decelerations. Results from these studies do not substantiate reports that FHR changes arising spontaneously, or in response to induced contractions, reflect satisfactorily the existing or subsequent fetal status.