Inspired by Gu et al 2025.[1]
TENS – transcutaneous electrical nerve stimulation
TEAS – transcutaneous electrical acupoint stimulation
SW-CRT – stepped wedge cluster randomised trial
LDU – labour and delivery unit
CEQ – childbirth experience questionnaire– key to acronyms
This is a large trial from Shanghai evaluating two non-pharmacological approaches to treating pain in labour (n=600). It is described as a stepped wedge cluster randomised trial (SW-CRT), which was new to me.
The SW-CRT design is used when you want everyone to eventually get the intervention, but you cannot roll it out to everyone at once – for practical, ethical, or logistical reasons. In this case, practical and logistical reasons meant that they used the same intervention for 3 months in each of the 4 labour and delivery units (LDUs), but they all started at a different time. The randomisation determined only the order in which the LDUs started the sequence of interventions. Each LDU was considered to be a cluster.
Usually, the sequence of interventions is also randomised in SW-CRTs, but in this case, I imagine that logistics related to training of the midwives meant that a set order was adopted, starting with the easiest intervention and progressing to the combination.
The control periods were either entirely at the beginning or at the end or divided between the two. The control was simply business as usual in the LDUs.
Women were recruited to the trial if they were in good health with singleton pregnancies and cephalic presentations and were booked for vaginal deliveries.
The first additional intervention was described as TENS in the paper, but really it was a mixture of TEAS and TENS, since the TENS was applied to acupuncture points on the left arm. The points used were LI4 and PC6. TENS was also applied to thoracolumbar and sacral areas in the midline. I assume a single pad on each site, since these were attached to a single channel of the device. Stimulation was applied to the level tolerated by the patient and the frequencies used were 2/100Hz with pulse widths of 0.6ms and 0.2ms. We are not told about the devices used.
The next intervention in sequence was ear and body acupressure. Vaccaria seeds were placed bilaterally on 5 auricular points: Shenmen, Uterus, Sympathetic, Subcortex, Endocrine. In addition to this, acupressure was applied to body acupuncture points depending on the stage of labour. A dedicated midwife was used to apply this intervention up to delivery of the placenta. This seems quite labour intensive (this is a different labour here of course).
Finally, the third 3-month sequence involved the use of both previous techniques together. So, a woman could have 10 ear seeds, almost constant acupressure massage to body points, and continuous TENS and TEAS throughout if she chose to continue with all of these interventions. That would mean quite a busy time for everyone involved.
VAS pain scores were recorded every 30 minutes up to 300 minutes (5 hours). These were not recorded by the midwife involved in the interventions. All three intervention periods resulted in a significant reduction in pain and a significant delay (well over an hour on average) before the first use of pharmacological analgesia. The TEAS / TENS group recorded the lowest numerical mean VAS pain scores throughout. Adding acupressure techniques did not improve on these scores.
Whilst pain is an important factor in childbirth, it is not the only thing that determines satisfaction with the experience. In this trial, the CEQ was used to evaluate childbirth experiences.[2] This is a 22-item questionnaire including 4 domains – Own capacity, Participation, Perceived safety, and Professional support.
Whilst this was developed in primiparous women, it has been applied here in a mixed group. Having said that, the groups were mostly made up of primips, with over 80% in this category. The TENS groups had a few percent more than the control or acupressure groups in this category, which would have given a marginal disadvantage to the TENS intervention.
The CEQ results came out in favour of TENS and acupressure or TENS alone in the total score and in all but one domain (Professional support). Acupressure alone was not better than control in the total score, but did have an impact (significant improvement) in two domains (Own capacity and Participation). The combination treatment was rated significantly higher than acupressure alone in the total CEQ score and the domains Own capacity and Perceived safety. The group receiving TENS alone was rated higher than that receiving acupressure alone in the domain Perceived safety. That last one is a curious result isn’t it!
The authors say that their results support the use of these techniques to empower women and enhance childbirth experiences. I would be more cautious about the acupressure intervention since it was so labour intensive in terms of staffing, whereas the TENS intervention was not.
References
1 Gu Y, Wang X, Wu J, et al. Acupoint stimulation combined with transcutaneous electrical nerve stimulation on labour pain: A stepped wedge cluster randomised controlled trial. Midwifery. 2025;145:104380. doi: 10.1016/j.midw.2025.104380
2 Dencker A, Taft C, Bergqvist L, et al. Childbirth experience questionnaire (CEQ): development and evaluation of a multidimensional instrument. BMC Pregnancy Childbirth. 2010;10:81. doi: 10.1186/1471-2393-10-81
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