Colour doppler evaluation of fetal hemodynamics in spontaneous versus prostaglandin E[2]-versus prostaglandin E[1] induced active Labor

ABSTRACT

To evaluate fetal hemodynamic changes before and during active labor, either spontaneous or prostaglandin E[2], [PGE[2]]-versus prostaglandin E[1] [PGE[1]] induced labor, one hundred and twenty healthy women at 37-41+ weeks gestation without signs of maternal medical problem and Fetal distress were investigated before and during labor. Group I [.40 women] had spontaneous active labor, Group II [40 women] were in active labor induced by intra-vaginal PGE[2] [1.5-3mg], Group III [40 women] were in active labor by oral PGE[1] [50-100 micro g]. Blood flow waveforms indices [systolic/diastolic ratio [S/D ratio], resistant index [RI] and pulsatility index [PI] were assessed by pulsed color Doppler from the umbilical artery [UA] and fetal middle cerebral artery [MCA] before and during labor. The groups were compared for the waveform indices, progress of labor and perinatal outcome including birth weight, umbilical artery pH at delivery. Apgar's score and neonatal intensive care unit [NICU] admission. It was found that, in group I, the S/D ratio, RI and PI became significantly decreased in the UA and MCA compared with those measured before labor [P < 0.05]. In group II, there were no significant changes in the waveform indices in the UA and MCA. While, in group III. all the waveform indices in MCA and the SID ratio in UA were significantly decreased [P <0.05] but the umbilical artery RI and PI were not significantly changed [P >0.05]. The incidence of UA Ph[<7.1] was significantly more in group II than group III and I[25%, 10%, and 5%], respectively [P < 0.05]. No other significant adverse perinatal outcomes were observed in the three groups. It was concluded that decreasing impedance in both the UA and MCA during spontaneous labor is a physiological fetal adaptation to labor to prevent fetal cerebral hypoxia by maintaining adequate brain blood flow during normal parturition. This fetal adaptation phenomenon was observed in the group I and III but not observed in group II which might explain the higher incidence of UA pH [<7.1] in group II, than that in group I and III