Highlight
• Transcutaneous auricular vagus nerve stimulation (taVNS) dramatically decreases the incidence of moderate to severe postpartum uterine contraction pain following elective cesarean delivery.
• taVNS reduces both incisional pain and psychological sequelae including postpartum depression and anxiety.
• Patients receiving taVNS experienced significantly better recovery quality and sleep quality in the immediate postoperative period.
• This noninvasive, safe technique may represent a novel adjunct for enhanced postpartum pain management and recovery facilitation.
Study Background and Disease Burden
Postpartum uterine contraction pain is a prevalent and distressing condition among women in the early puerperium after delivery, especially after cesarean sections. This pain arises from intermittent strong uterine contractions as the uterus involutes to its pre-pregnancy size. While often under-recognized, severe uterine contraction pain substantially diminishes maternal well-being, impairs mobility, and may interfere with mother-infant bonding and breastfeeding. Conventional analgesics often provide incomplete relief or come with potential side effects, creating an unmet need for safe, effective, and nonpharmacological alternatives for pain control in this vulnerable population.
Neuromodulation techniques, including transcutaneous auricular vagus nerve stimulation (taVNS), have garnered interest due to their analgesic and anxiolytic properties. The auricular branch of the vagus nerve offers an accessible peripheral entry point to modulate central pain pathways noninvasively. taVNS has demonstrated efficacy in various acute and chronic pain syndromes, but its application for postpartum uterine contraction pain remains understudied.
Study Design
This randomized clinical trial conducted at the Affiliated Hospital of Xuzhou Medical University, China, enrolled 156 women aged 18 years or older scheduled for elective cesarean delivery under combined spinal-epidural anesthesia. Participants were randomly assigned in a 1:1 allocation to receive either active taVNS or sham taVNS interventions. The treatment consisted of 30-minute stimulation sessions once daily on the day of surgery and postoperative days 1 and 2.
The primary endpoint was the incidence of moderate to severe postpartum uterine contraction pain (defined as a visual analogue scale [VAS] score ≥4) on postoperative day 3. Secondary endpoints included peak uterine contraction and incision pain scores, assessment of postpartum anxiety and depression using validated scales (PRAQ-R2 and EPDS respectively), recovery quality evaluated by ObsQoR-11, and sleep quality measured by the Leeds Sleep Evaluation Questionnaire (LSEQ).
Key Findings
The trial demonstrated a marked reduction in the incidence of moderate to severe uterine contraction pain in the active taVNS group, with only 5.1% (4 of 78) reporting moderate to severe pain compared with 28.2% (22 of 78) in the sham group. This corresponded to a relative risk reduction of 82% (relative risk 0.18; 95% confidence interval [CI] 0.07–0.50; P < .001).
Furthermore, the median VAS score for incisional pain on postoperative day 3 was significantly lower in the taVNS group (2.20; interquartile range [IQR], 2.00–2.50) compared to the sham group (3.00; IQR, 2.60–3.33). Such a reduction in pain intensity can meaningfully improve patient comfort and mobility.
Psychological outcomes also favored the taVNS group: the median Edinburgh Postnatal Depression Scale (EPDS) score was 3.00 (IQR, 2.00–4.00) versus 5.00 (IQR, 3.00–6.00) in controls, and anxiety scores measured by the Pregnancy-Related Anxiety Questionnaire-Revised 2 (PRAQ-R2) were also lower at 13.50 (IQR, 12.00–15.00) versus 15.00 (IQR, 13.75–17.00), indicating better psychological well-being.
Quality of recovery, as measured by the ObsQoR-11 score on postoperative day 3, was superior in the active group with a median of 104 (IQR, 103–105), compared with 99 (IQR, 96–101) in the sham group. Similarly, sleep quality on postoperative day 2 was significantly better with taVNS (LSEQ score median 52.00, IQR 50.00–55.00) versus sham (47.50, IQR 43.00–52.00), highlighting improved rest and recuperation.
Importantly, the intervention was well tolerated with no reported adverse effects attributable to taVNS, underscoring its safety profile as a noninvasive analgesic option for postpartum women.
Expert Commentary
These findings are particularly significant in the realm of postpartum care where nonpharmacological options for pain relief are highly desirable to minimize opioid use and associated risks in breastfeeding mothers. The favorable impact of taVNS on both somatic pain and psychological distress aligns with the known modulatory effects of vagus nerve stimulation on neuroimmune pathways, nociceptive processing, and mood regulation. Although these results are promising, further studies are warranted to explore the long-term benefits, optimal stimulation parameters, and applicability across diverse populations.
One limitation is the relatively short follow-up confined to the immediate postoperative period; extended evaluation could determine if benefits persist or influence longer-term postpartum recovery milestones. Additionally, study replication in broader clinical settings would support generalizability.
Conclusion
This rigorously conducted randomized clinical trial provides compelling evidence that transcutaneous auricular vagus nerve stimulation is an effective, safe, and noninvasive strategy to significantly reduce postpartum uterine contraction pain and incisional pain following cesarean delivery. Beyond analgesia, taVNS contributes to improved psychological outcomes, recovery quality, and sleep, marking it as a promising tool in multimodal postpartum care. Incorporation of taVNS could enhance patient comfort and satisfaction, reduce reliance on systemic analgesics, and foster better overall postpartum recovery.
Future research should aim to clarify mechanisms, refine treatment protocols, evaluate cost-effectiveness, and assess integration into postpartum clinical pathways worldwide.
References
1. Xiong X, Tao M, Zhao W, et al. Transcutaneous Auricular Vagus Nerve Stimulation for Postpartum Contraction Pain During Elective Cesarean Delivery: A Randomized Clinical Trial. JAMA Netw Open. 2025;8(8):e2529127. doi:10.1001/jamanetworkopen.2025.29127.
2. Farmer AD, et al. Neuromodulation in pain and mood disorders: Vagus nerve stimulation and beyond. Nat Rev Neurol. 2020;16(8):531–543.
3. Starkweather AR, et al. Mechanisms of Vagus Nerve Stimulation for Pain Reduction and Mood Regulation. Int J Mol Sci. 2021;22(2):642.
4. Dennis CL, et al. The Edinburgh Postnatal Depression Scale: a review of the validation studies. J Psychosom Res. 2005;58(2):315-323.
