The Impact of Transcutaneous Electrical Nerve Stimulation (TENS) on the Consecutive Stages of Labour and Perinatal Outcomes-A Retrospective Cohort Study.

Background: Over recent years, several pain management techniques have been proposed to control labour pain, including pharmacological and non-pharmacological interventions. Transcutaneous electrical nerve stimulation (TENS) is considered a safe, non-invasive, easily applicable, and inexpensive pain relief method. This study aimed to investigate the impact of TENS on consecutive labour stages and on maternal and neonatal outcomes. Methods: This retrospective, single-centre cohort study covered a two-year period (1 January 2022-31 December 2023). A total of 1451 women met the inclusion criteria. TENS was applied in 203 of them. In 54.67% of cases, TENS was combined with water immersion and, in 42.85%, with water immersion and Entonox (N2O and O2 mixture). Two groups of patients that either made use of TENS, or not, to reduce labour pain, were compared to assess the effect of TENS on the course of labour and the condition of the newborn. Results: The women in the TENS group experienced a significantly longer first stage of labour. There was no statistically significant difference between the groups in terms of oxytocin usage, perineal tearing, episiotomy, and umbilical cord blood pH. The simultaneous application of TENS and water immersion contributed to prolonging the first stage of labour relative to their independent effects. Conclusions: The application of TENS may prolong the first stage of labour, without increasing the rate of perineal tearing and episiotomy and without any adverse effects on the condition of the newborn.