Course and predictive value of fetal heart rate parameters

The present study concerns the developmental character of the fetal heart rate (FHR) pattern and the implications of predicting the perinatal outcome. Data from 443 patients undergoing 2193 nonstress tests were analyzed retrospectively. We found a significant increase of accelerations more than 15 beats/min, of accelerations associated with fetal movements, of fetal movements registered by the tocotransducer, the frequency of oscillations, and of the Fischer score values throughout gestation. The number of short FHR decreases and the mean baseline level declined throughout gestation. A long duration of absent or reduced baseline variability registered even 6 weeks before delivery was associated with low Apgar score values. Late decelerations and contractions registered early in pregnancy were also correlated to a poor outcome. Tachycardia and a low number of accelerations were only correlated to a poor perinatal outcome shortly before the delivery. Fetal movements not associated with FHR accelerations were an early indicator of a poor neonatal outcome. Scoring systems did not generally improve the predictive value of FHR patterns.