Intrapartum fetal activity.

Fetal activity throughout pregnancy has been thoroughly studied. Relatively little informations regarding intrapartum fetal activity is available. Richardson et al. [8] found no fetal respiratory movements. While Boylan et al. [2] and Whittman et al. [12] reported decreased fetal breathing movements in active labor. This study was undertaken to evaluate the normal pattern of fetal activity in labor. Fetal movements (FM) and fetal breathing movements (FBM) were monitored by realtime ultrasound during active labor at term. The incidence of FM and FBM were measured in 18 fetuses. Results were correlated with simultaneous fetal heart rate (FHR) changes, postpartum cord blood pH and Apgar score. Recordings were made for one hour on every patient. The mean percentage incidence (PI) of FM was 19.5 per cent (range: 10.1-28.6 percent) and FBM was 8.5 per cent (range: 0-27 percent). All FM were associated with FHR accelerations, stronger movements were associated with higher FHR accelerations. No FHR accelerations were observed with FBM alone, unless accompanied by fetal movement. The lowest PI of total fetal activity (TFA, i.e. FM plus FBM) was 12.1 per cent. Movements decreased as labor progressed, while FBM remained unaltered. All newborns had cord venous blood pH of greater than 7.25 and Apgar scores of greater than or equal to 7, at five minutes. Our data suggest that in the normal uncompromised fetus, FM and FBM continue during labor at term. However, while FM tends to decrease as labor progresses. FBM tends to be constant throughout labor. This finding might indicate the autonomous nature of FBM.(ABSTRACT TRUNCATED AT 250 WORDS)