Maternal and foetal physiological response of sacral surface electrical stimulation during pregnancy: A preliminary study

New Findings What is the central question of this study? The physiological response to sacral neuromodulation by pregnant women and foetuses has not been previously explored. What is the main finding and its importance? Sacral surface electrical stimulation had no adverse effect on pregnant women and foetuses at least 36 weeks of gestation. It may cause uterine relaxation resulting from decreased uterine artery pulsatility index and increased umbilical venous flow volume and thereby improve utero-placental perfusion and improve lower back pain. This study aimed to examine the impact of sacral surface electrical stimulation on maternal and foetal physiology during pregnancy. Ten pregnant women at 36 weeks of gestation without multiple gestations, foetuses with malformations, foetal growth restriction, hypertensive disorders, polyhydramnios, or oligohydramnios were enrolled. This prospective study monitored maternal and foetal physiological responses before and after sacral surface electrical stimulation for single pregnancies. Sacral surface electrical stimulation was performed once per patient. Each parameter was measured directly before and then immediately after stimulation. Follow-up measurements were conducted at 12 h, 1 day, 2 days and 7 days after stimulation. Variables of interest were compared before and after the stimulation. Regarding the foetal Doppler measurements, significant differences were not found in the umbilical and middle cerebral artery pulsatility index. However, foetuses showed a significant increase in the umbilical venous flow volume. The uterine contraction frequency and the maternal uterine artery pulsatility index significantly decreased. Pregnancy outcomes, and rates of caesarean section, foetal distress, and neonatal asphyxia were not confirmed. In conclusion, sacral surface electrical stimulation had no adverse effects on pregnant women or foetuses at 36 weeks of gestation and might improve utero-placental perfusion and lower back pain.