BANFF, ALTA. — Combined spinal epidural produces a transient decrease in uterine but not umbilical artery blood flow that does not impact the fetal circulation, fetal heart rate pattern, or immediate neonatal outcome, according to the results of a small study.
“In normal pregnancies, we were able to a find a statistically but not clinically significant decrease in the uterine blood flow after CSE [combined spinal epidural],” Dr. Cristian Arzola said at the annual meeting of the Society for Obstetric Anesthesia and Perinatology.
The prospective study included 30 healthy patients in active labor with singleton, uncomplicated pregnancies at term. Pain, maternal blood pressure, fetal and maternal heart rate, blood-flow velocity waveforms, and pulsatility indices (PI) of the uterine and fetal umbilical arteries were measured before and at 5, 10, 15, and 30 minutes following administration of CSE (bupivacaine and fentanyl).
Dr. Arzola observed a drop in maternal systolic arterial blood pressure of 20% from baseline that was significant only at 10 and 15 minutes after CSE. Maternal heart rate dropped significantly at all time points, but remained within normal range. Pulsatility indices for the uterine artery were increased significantly at 10 minutes, indicating reduced blood flow; however, the PI for the umbilical artery remained stable, reported Dr. Arzola of the University of Chile, Santiago.
As expected, pain scores dropped dramatically, and with them adrenaline levels, which decreased more than 50% from baseline. Fetal heart rate did not change significantly, and tracings did not show altered patterns. Apgar scores and cord blood gases were all within normal range, and there were no signs of fetal distress, he said.