Doppler Measurement of the Changes of Fetal Umbilical and Middle Cerebral Artery Velocimetric Indices During Continuous Epidural Labor Analgesia

Objective: Although complications of the epidural technique are known to affect the fetus adversely, there are no data indicating that regional analgesia directly causes harmful effects to the fetus. Our purpose was to determine the effect of epidural labor analgesia on the Doppler velocimetric indices of the uterine and fetal umbilical and middle cerebral arteries. Methods: Doppler velocimetry indices, systolic/diastolic ratios, pulsatility index, and resistance index, of the fetal umbilical artery and uterine artery were recorded in 15 women receiving continuous epidural analgesia with 0.075% bupivacaine and 0.0002% fentanyl during labor; the same indices were recorded of the fetal umbilical and middle cerebral arteries in 10 women receiving the same analgesia. The cerebroplacental Doppler ratio was calculated. Maternal and neonatal outcome data were also recorded. Results: Velocimetric indices of the fetal umbilical and middle cerebral artery after epidural infusion were not significantly different from the pre-epidural infusion levels. Indices of the maternal uterine artery were significantly increased after epidural infusion. The cerebroplacental ratio did not change after the beginning of epidural infusion. Neonatal outcome parameters (1- and 5-min Apgar scores) were all within normal limits. Conclusions: These data suggest that although velocimetric indices of the maternal uterine artery are affected by continuous epidural labor analgesia, fetal circulation, as measured by Doppler velocimetric indices, is not altered.