Variable decelerations of the fetal heart rate during antenatal monitoring.

Variable decelerations were observed in only 52 (0,75%) of 4 509 patients in whom the fetal heart rate was monitored antenatally. In 14 patients fetal monitoring was performed less than 1 week before the test with variable decelerations. The results of 9 of these tests were normal. Tests were repeated within 1 week in 16 patients; normal results were seen in 11 of these. Fetal movements and acceleration patterns of the fetal heart rate occurred in 54% and 23% of patients respectively. The interval between testing and delivery ranged from 0 to 98 days, with a mean of 14 days, and there were no intra-uterine deaths. Fetal distress during labour was rare. Fetal outcome was favourable in only 4 of the 7 cases in which variable decelerations were complicated by reduced beat-to-beat variability. Variable decelerations during the antepartum period therefore do not necessarily indicate a complicated labour.