The efficacy and safety of transcutaneous electrical nerve stimulation for labor analgesia in the first stage of labor: a qualitative and quantitative analysis

Aim: Labor pain represents a significant challenge for parturients during childbirth. Transcutaneous electrical nerve stimulation (TENS) is an effective analgesic modality. However, its efficacy and safety for intrapartum analgesia remain unclear. To address this knowledge gap, we performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to comprehensively assess the analgesic effectiveness and safety profile of TENS during the first stage of labor. Methods: We searched databases from inception to October 17, 2024 and updated them to July 22, 2025. Paired researchers independently extracted data and assessed the risk of bias. All meta-analyses were performed via random effects models, and the GRADE approach was employed to evaluate the certainty of evidence. Results: We included 51 randomized controlled trials (10,038 participants, all females). Low evidence showed that compared with the blank control, parturients using TENS may experience more pain relief (WMD -1.98 cm, 95%CI -2.6 to -1.35 cm, the modelled RD 52, 95% CI 37 to 62%), parturients using TENS may shorten the duration of the first stage of labor (WMD -46.78 min,95% CI -61.32 to -32.25 min); compared with the epidural analgesia groups, parturients using TENS may shorten the duration of the first stage of labor (WMD-62.22 min, 95%CI -92.51 to -31.94 min). Conclusion: Compared with the blank control, TENS may reduce pain intensity and shorten the duration of the first stage of labor in parturients, with little to no difference in adverse events. When compared to epidural analgesia, TENS may shorten the duration of the first stage of labor, with very small differences observed in analgesic efficacy or adverse effects. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251066439, identifier PROSPERO (CRD420251066439).