Efficacy of Electroacupuncture for Chronic Pelvic Pain: A Randomized, Single-Blind, Sham-Controlled Trial

Abstract

Objective

To evaluate the efficacy and safety of electroacupuncture in the management of chronic pelvic pain (CPP).

Methods

This randomized, single-blind, sham-controlled trial enrolled 66 women aged 18 to 50 years with CPP. Participants were randomly assigned in a 1:1 ratio to receive either electroacupuncture or sham electroacupuncture. Each treatment session lasted 30 minutes and was administered three times weekly, with treatment suspended during menstruation and subsequently resumed until 24 sessions were completed. The primary outcomes were lower abdominal pain and lumbosacral pain assessed using the Visual Analogue Scale (VAS) at baseline, week 8 (end of treatment), and week 16 (8-week follow-up). Secondary outcomes were depression and anxiety assessed using the Hamilton Depression Rating Scale HAMD) and Hamilton Anxiety Rating Scale (HAMA) before and after treatment.

Results

Sixty-six women were randomized, with 32 assigned to electroacupuncture and 34 to sham electroacupuncture. At week 8, the reported between-group effect estimates were 3.37 (95% CI, 2.62–4.12) for lower abdominal pain and 3.14 (95% CI, 2.42–3.87) for lumbosacral pain (both p < 0.001). At week 16, the corresponding reported estimates were 3.69 (95% CI, 2.90–4.48) and 3.38 (95% CI, 2.63–4.13), respectively (both p < 0.001), indicating that the reduction in pain was maintained during follow-up. No significant between-group differences were observed in changes in HAMD or HAMA scores after treatment. No serious adverse events were reported.

Conclusion

Electroacupuncture may reduce lower abdominal and lumbosacral pain in women with CPP, and the observed reduction was maintained through the 8-week follow-up period. No specific between-group benefit was demonstrated for anxiety or depressive symptoms. Larger studies with longer follow-up are warranted.

Introduction

Chronic pelvic pain (CPP) is a heterogeneous and multidimensional condition that substantially impairs quality of life. Its clinical presentation may involve gynecological, urological, gastrointestinal, musculoskeletal, neurological, and psychosocial components.^1–5 Acupuncture has been increasingly used for chronic pain management.⁶ However, much of the available evidence relevant to pelvic pain has focused on male chronic prostatitis/chronic pelvic pain syndrome or endometriosis-associated pain,^7,8 and high-quality evidence in women with non-cyclic CPP of unclear etiology remains limited. The present randomized, single-blind, sham-controlled trial therefore evaluated electroacupuncture using a nonpenetrating sham electroacupuncture control, with lower abdominal pain and lumbosacral pain assessed as the primary clinical outcomes.

Materials and Methods

Study Design

This study was designed as a randomized, single-blind, sham-controlled clinical trial conducted from January 1, 2024, to November 30, 2025. Participant screening was conducted in two stages: pre-screening and formal screening. Pre-screening was performed by outpatient physicians and investigators at the International Peace Maternity and Child Health Hospital affiliated with Shanghai Jiao Tong University School of Medicine using electronic medical records, outpatient chief complaints, and referral information during clinic visits. Basic eligibility information, including demographic characteristics, pelvic pain-related symptoms, relevant medical history, and willingness to participate, was collected to identify potentially eligible participants. Women who passed pre-screening proceeded to formal screening.

The trial was approved by the Ethics Committee of Shanghai Jiao Tong University School of Medicine (GKLW-A-2024-011-02) and registered at the Chinese Clinical Trial Registry (ChiCTR; Registration No. ChiCTR2400086758) on July 10, 2024. After ethics approval and registration, formal screening was initiated. Participants who provided written informed consent underwent face-to-face interviews, medical history collection, clinical assessments, and verification of the inclusion and exclusion criteria (see Participants below for details).

Participants

Women were recruited from the outpatient department of the International Peace Maternity and Child Health Hospital affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai, China, and were required to meet the following inclusion criteria: ① age 18 to 50 years, with a history of sexual activity and premenopausal status; ② a Visual Analogue Scale (VAS) score ≥ 3 for lower abdominal pain; ③ fulfillment of the diagnostic criteria for chronic pelvic pain according to the American Chronic Pelvic Pain Society, including: (a) persistent pelvic pain that may be associated with sexual intercourse, urination, or defecation; (b) exclusion of pelvic pain caused by underlying conditions such as infection or malignancy; (c) absence of a clearly identifiable cause of CPP; (d) significant pain-related impairment in quality of life; ④ persistence of pelvic pain for at least 6 months; ⑤ willingness to participate and ability to comply with the study protocol.

Participants meeting any of the following criteria were excluded: ① pregnancy or lactation; ② severe dysfunction of major organs, including the heart, liver, or kidneys; ③ psychiatric disorders or cognitive impairment that could affect the collection or evaluation of study data; ④ diagnosis of gynecological conditions associated with pelvic pain, including endometriosis, adenomyosis, or abnormal uterine bleeding; ⑤ other conditions considered unsuitable for study participation, such as severe psychological disorders or immune diseases.

Sample Size Estimation

Sample size was calculated using the formula for two independent means: n = [(Zα/2 + Zβ)² × σ²] / δ² × (Q1⁻¹ + Q2⁻¹). The significance level (α) was set at 0.05 (two-sided), and the power (1-β) was set at 0.9, with Q1 = Q2 = 0.5. Based on previous literature, the pooled standard deviation (s) was estimated as 46.64, and the expected between-group difference (δ) was estimated as 51.83. Substitution of these parameters yielded a required sample size of approximately 25 participants per group. Accounting for a 20% dropout rate, we aimed to enroll 30 participants per group. A total of 66 participants were ultimately enrolled in the study.

Randomization and Blinding

A total of 66 participants were enrolled in the study and randomly assigned in a 1:1 ratio to either the electroacupuncture group (n = 32) or the sham electroacupuncture group (n = 34). Randomization was performed by independent statistical personnel, who prepared random allocation cards sealed in sequentially numbered opaque envelopes. The envelopes were maintained by designated personnel not involved in treatment or assessment. After eligibility was confirmed, the corresponding numbered envelope was opened to determine treatment allocation.

Intervention

The interventions were administered by two licensed acupuncturists with Doctor of Traditional Chinese Medicine qualifications and more than 10 years of clinical experience. Prior to trial initiation, both acupuncturists completed standardized training in the study procedures. The treatment period lasted 8 weeks. Each treatment session lasted 30 minutes, three times per week (once every other day). Treatment was suspended during menstruation and resumed thereafter. A total of 24 treatment sessions were completed.

Participants assigned to the electroacupuncture group received electroacupuncture therapy. Before each treatment, participants were instructed to empty their bladder and were then positioned supine. Disposable sterile stainless-steel needles (0.30 × 40/50 mm) were inserted to a depth of 15–35 mm at Zhongji (Conception Vessel 3, CV3), Guanyuan (Conception Vessel 4, CV4), bilateral uterine points (extraordinary points outside the meridians, EX-CA1), bilateral Sanyinjiao (Spleen 6, SP6), and bilateral Zusanli (Stomach 36, ST36). After De Qi was elicited, electrodes were connected between one uterine point and Zhongji and between the contralateral uterine point and Guanyuan. Continuous-wave electrical stimulation was delivered using a KWD-808I pulse electrotherapy device (Great Wall), with intensity adjusted according to participant tolerance for 30 minutes. The remaining needles were retained for 30 minutes with balanced reinforcing-reducing manipulation. Acupoint localization followed GB/T 21709.20–2009 and GB/T 12346. The schematic diagram of acupoint locations is presented in Supplementary Figure 1.

Participants in the sham electroacupuncture group received a nonpenetrating sham procedure at the same acupoints. Blunt-tip sham electroacupuncture needles (Suzhou Medical Supplies Factory Co., Ltd.) contacted the skin without penetration. The needle handle was connected to the electroacupuncture device, but stimulation intensity was maintained at zero. Treatment duration and frequency were identical to those used in the electroacupuncture group.

The following precautions were implemented during treatment. Prior to each treatment session, participants underwent clinical evaluation to determine suitability for treatment. Sessions were avoided in cases of fatigue, excessive sweating, severe diarrhea, physical weakness, or marked psychological tension. For participants receiving electroacupuncture for the first time, the procedures were explained in detail to reduce anxiety and improve adherence.

During treatment, electroacupuncture intensity was gradually and evenly increased from zero to the maximum tolerable level. Sudden increases in stimulation intensity were avoided, and participants’ responses were continuously monitored throughout. If pelvic pain worsened during treatment, immediate gynecological assessment was performed and managed according to medical recommendations. In the event of adverse procedural reactions, including fainting, needle fixation, bent needle, broken needle, or hematoma formation, treatment was discontinued immediately and standard emergency management procedures were followed. The event and management measures were documented in writing. Curtains were used to separate participants during treatment sessions, and acupuncturists were instructed not to disclose treatment details, thereby maintaining participant blinding. No additional therapies for CPP were permitted during the study period in either group.

Outcomes

Baseline demographic and clinical characteristics of the participants were statistically analyzed and compared, including age, marital status, educational level, disease duration (months), body mass index (BMI), number of childbirths, mode of delivery, and comorbidities including hypertension and diabetes mellitus.

The primary outcomes were changes in VAS scores for lower abdominal pain and lumbosacral pain, assessed at baseline, week 8 and week 16.^9,10 VAS scores were recorded and reported in points, with higher scores indicating greater pain intensity. Participants recorded the maximum pain intensity experienced during the relevant assessment period.

Secondary outcomes included depression and anxiety, assessed using the Hamilton Depression Rating Scale (HAMD) and Hamilton Anxiety Rating Scale (HAMA). Assessments were performed before treatment and at the end of the 8-week treatment period.

Statistical Analysis

Data analysis was performed by statisticians blinded to treatment allocation. Statistical analyses were performed using SPSS version 26.0. All 66 randomized participants were included in the analysis; there were no dropouts or missing outcome data. Normally distributed continuous data were expressed as mean ± standard deviation. Independent-samples t-tests were used for between-group comparisons, and paired t-tests were applied for within-group comparisons. The χ²-test or Fisher exact test, as appropriate, was used for comparisons of categorical variables. A two-sided p value < 0.05 was considered statistically significant.

Results

Participant Characteristics

From January 1, 2024, to November 30, 2025, 138 women were screened for eligibility and 72 women were excluded according to the predefined inclusion and exclusion criteria (Figure 1). Ultimately, 66 participants were enrolled and completed all treatment sessions and follow-up assessments, including 32 in the electroacupuncture group and 34 in the sham electroacupuncture group. No participants were lost to follow-up.

Figure 1.

Flow diagram of participant recruitment, randomization, allocation, follow-up, and analysis.

Age differed significantly between groups (p = 0.016; standardized difference, 0.61), whereas no statistically significant between-group differences were observed for marital status, educational level, disease duration, BMI, parity, mode of delivery, hypertension, diabetes mellitus, or baseline HAMD and HAMA scores (Table 1).

Table 1.

Baseline Demographic and Clinical Characteristics of the Electroacupuncture and Sham Electroacupuncture Groups

Group	Sham electroacupuncture (N=34)	Electroacupuncture (N=32)	Standardize diff.	P-value
Disease course (months)	38.41 ± 8.98	40.00 ± 9.94	0.17 (−0.32, 0.65)	0.498
BMI	22.18 ± 2.37	21.94 ± 1.98	0.11 (−0.37, 0.59)	0.659
Age	42.74 ± 4.41	45.50 ± 4.64	0.61 (0.12, 1.10)	0.016
Marital status			0.10 (−0.39, 0.58)	1.000*
Married	31 (91.18%)	30 (93.75%)
Divorced	3 (8.82%)	2 (6.25%)
Education levels			0.28 (−0.20, 0.77)	0.722*
Below high school	1 (2.94%)	3 (9.38%)
High school	9 (26.47%)	7 (21.88%)
College	19 (55.88%)	18 (56.25%)
Postgraduate	5 (14.71%)	4 (12.50%)
Hypertension			0.27 (−0.21, 0.76)	0.348*
0	33 (97.06%)	29 (90.62%)
1	1 (2.94%)	3 (9.38%)
Diabetes			0.16 (−0.32, 0.64)	0.608*
0	33 (97.06%)	30 (93.75%)
1	1 (2.94%)	2 (6.25%)
Parity			0.33 (−0.15, 0.82)	0.183
≤1	29 (85.29%)	23 (71.88%)
>1	5 (14.71%)	9 (28.12%)
C-section			0.14 (−0.34, 0.62)	0.569
0	20 (58.82%)	21 (65.62%)
1	14 (41.18%)	11 (34.38%)

Notes: Table results: Mean ± SD / N (%). P value*: Independent-samples t tests were used for continuous variables. The χ²-test or Fisher exact test, as appropriate, was used for categorical variables.

Abbreviation: EA, electroacupuncture.

Primary and Secondary Outcomes

Low Abdominal Pain VAS Score and Lumbosacral Pain VAS Score

No statistically significant differences were observed between the two groups in lower abdominal pain or lumbosacral pain VAS scores at baseline. At week 8, the electroacupuncture group had lower VAS scores than the sham electroacupuncture group. The reported between-group effect estimates were 3.37 (95% CI, 2.62–4.12) for lower abdominal pain and 3.14 (95% CI, 2.42–3.87) for lumbosacral pain (both p < 0.001). At week 16, the corresponding reported estimates were 3.69 (95% CI, 2.90–4.48) and 3.38 (95% CI, 2.63–4.13), respectively (both p < 0.001), showing that the reduction in pain observed at the end of treatment was maintained during the 8-week follow-up period (Table 2, Figure 2).

Table 2.

Primary and Secondary Outcomes in the Electroacupuncture and Sham Electroacupuncture Groups at Baseline, week 8, and week 16

Outcome	Sham Electroacupuncture (N=34)	Electrocupuncture (N=32)	Difference (95% CI)	P-value
Low abdominal pain VAS score
Before treatment	5.32 ± 0.68	5.31 ± 0.64	0.02 (−0.47, 0.50)	0.947
After treatment	5.18 ± 0.72	2.78 ± 0.71	3.37 (2.62, 4.12)	<0.001*
8 weeks after treatment	5.09 ± 0.71	2.66 ± 0.60	3.69 (2.90, 4.48)	<0.001*
Lumbosacral pain VAS score
Before treatment	5.12 ± 0.81	5.31 ± 0.59	0.28 (−0.21, 0.76)	0.270
After treatment	4.97 ± 0.90	2.53 ± 0.62	3.14 (2.42, 3.87)	<0.001*
8 weeks after treatment	5.00 ± 0.89	2.56 ± 0.50	3.38 (2.63, 4.13)	<0.001*
Hamilton Depression Rating Scale
Before treatment	20.09 ± 1.68	19.50± 1.68	0.35 (−0.14, 0.84)	0.160
After treatment	8.91 ± 1.85	8.94 ± 1.52	0.02 (−0.47, 0.50)	0.951
Hamilton Anxiety Rating Scale
Before treatment	18.09 ± 0.62	18.25± 0.95	0.20 (−0.28, 0.69)	0.413
After treatment	8.91 ± 1.44	8.69 ± 1.33	0.16 (−0.32, 0.65)	0.515

Notes: Data are presented as mean ± standard deviation (SD) for group scores and mean difference (95% CI) for between-group comparisons. *P < 0.05 indicates statistical significance compared to the sham acupuncture group.

Abbreviation: VAS: Visual Analog Scale.

Figure 2.

Mean VAS scores for lower abdominal pain (A) and lumbosacral pain (B) at baseline, week 8, and week 16 in the electroacupuncture and sham electroacupuncture groups. Data are presented as mean ± standard deviation (SD).

Hamilton Depression Rating Scale (HAMD) and Hamilton Anxiety Rating Scale (HAMA)

Baseline HAMD and HAMA scores did not differ significantly between groups. After 8 weeks of treatment, both scores decreased within each group; however, no statistically significant between-group differences were observed for HAMD or HAMA (Table 2).

Safety

During the study period, subcutaneous hemorrhage at the needle insertion site was reported in 3 of 32 participants (9.4%) in the electroacupuncture group and 2 of 34 participants (5.9%) in the sham electroacupuncture group. No intervention was required. No serious adverse events were reported.

Discussion

CPP is a common public health concern among women. Due to the absence of a universally accepted definition, considerable variability exists in reported CPP prevalence across studies. In 2006, the World Health Organization (WHO) published a systematic review of CPP prevalence from 1966 to 2004, reporting that the global prevalence of non-cyclic pelvic pain ranged from 4% to 43.4%.¹¹ A population-based survey of the UK General Practice Database reported that nearly 280,000 of 1.7 million women attending outpatient clinics between 1991 and 1995 were diagnosed with CPP, corresponding to a prevalence rate of approximately 16.4%.¹² A cross-sectional study of 2,397 women aged 14 to 49 years in Ecuador reported a CPP prevalence rate of 9.8%.¹³ Epidemiological data on CPP prevalence in China remains limited. He et al conducted a survey of 1,468 women aged 18 to 58 years in Changchun between 2011 and 2013 and reported a CPP prevalence rate of 17.6%.¹⁴

CPP is characterized by complex and heterogeneous symptoms and a prolonged course, poor recovery, and high recurrence, all of which substantially impair physical health, psychological well-being, and quality of life.⁵ A cross-sectional study conducted in Australia in 2021 of 500 women with CPP, demonstrated that CPP adversely affected family relationships in 11% of participants, social interactions in 12%, and occupational functioning in 4%.¹⁵ Additionally, 16% required long-term pharmacological treatment and approximately 40% reported difficulty concentrating during work or study due to CPP. Furthermore, fertility rates among reproductive-aged women with CPP have been reported to be reduced by 45% to 64%, which may negatively affect quality of life and marital relationships.^16,17 CPP is also closely associated with psychological disorders; a bidirectional relationship between CPP and psychological distress has been reported, which may further influence pain severity and prognosis.¹⁸

Currently, conventional Western medical management of CPP primarily includes pharmacological therapy, surgical intervention, and physical therapy for pain relief. Nonsteroidal anti-inflammatory drugs and opioid analgesics are commonly used in clinical practice; however, drug dependence, gastrointestinal adverse reactions, and other treatment-related side effects remain significant concerns. Hence, there is a need to identify more effective, safer, and individualized therapeutic strategies. Traditional Chinese Medicine (TCM), a distinctive medical system with a long clinical history, has accumulated extensive experience and unique therapeutic approaches. Electroacupuncture (EA), a key therapeutic modality in TCM, has been widely utilized in the treatment of various conditions and has demonstrated efficacy in chronic pain management. Previous studies have suggested that EA may exert therapeutic effects through multiple mechanisms, including modulation of neurotransmitter release, microcirculation, and immune function.^19–22 Wei et al reported that mind-regulating EA combined with rehabilitation therapy significantly alleviated pain and improved anxiety and depressive symptoms in male patients with chronic pelvic pain syndrome, while also reducing serum levels of IL-6, PGE2, and NF-κB.²³ These findings suggest that the analgesic effects of EA may be associated with reductions in inflammatory mediators including IL-6, PGE2, and NF-κB. Luo et al demonstrated that EA combined with conventional Western medicine was superior in the treatment of CPP and significantly reduced pain severity.²⁴ Li et al reported that EA effectively improved clinical symptoms and quality of life in patients with chronic prostatitis/chronic pelvic pain syndrome.²⁵

In the present study, 66 women with CPP were enrolled and completed follow-up, including 32 assigned to electroacupuncture and 34 to sham electroacupuncture. Electroacupuncture was associated with lower abdominal and lumbosacral pain scores at week 8, and the observed reductions were maintained through week 16. HAMD and HAMA scores decreased within both groups, but the absence of statistically significant between-group differences does not support a specific psychological effect of electroacupuncture.

Several limitations should be acknowledged. First, the sample size was modest and the study was conducted at a single center. Second, participant blinding success was not formally assessed, and the sensory experience of penetrating electroacupuncture with De Qi and electrical stimulation may have differed from the nonpenetrating sham procedure. Third, the primary pain outcomes were assessed repeatedly using separate independent-samples and paired t tests; no mixed-effects model, age adjustment, or multiplicity correction was performed. Fourth, a baseline age imbalance was present between groups. Finally, follow-up was limited to 8 weeks after treatment, so longer-term persistence of benefit and recurrence cannot be determined.

Conclusion

Electroacupuncture may reduce lower abdominal and lumbosacral pain in women with CPP of unclear etiology, and the observed reductions were maintained during the available 8-week post-treatment follow-up. No specific between-group benefit was demonstrated for anxiety or depressive symptoms. Given the modest sample size, baseline age imbalance, limited follow-up, and absence of formal blinding assessment or longitudinal mixed-model analysis, these findings should be interpreted cautiously and confirmed in larger multicenter trials.

Funding Statement

This research was supported by Fundamental Research Funds for the Central Universities (YG2024QNA60, YG2022QN110), Shanghai Municipal Health Commission Traditional Chinese Medicine Research Project (2024QN048). The funders had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.

Trial Registration

Registration URL: https://www.chictr.org.cn/showproj.html?proj=235648.

Registration date: 2024-07-10.

Registration number: ChiCTR2400086758.

Abbreviations

ACOG, American College of Obstetricians and Gynecologists; CPP, Chronic pelvic pain; HAMA, Hamilton Anxiety Rating Scale; HAMD, Hamilton Depression Rating Scale; VAS, Visual Analogue Scale.

Data Sharing Statement

The conclusions drawn from this study are based on the data provided by the corresponding author upon request. Data are available from the corresponding author (Furui Jin; email: jinfuruifrju@126.com) upon reasonable request.

Ethics Approval and Consent to Participate

The study protocol was approved by the Ethics Committee of Shanghai Jiao Tong University School of Medicine (GKLW-A-2024-011-02) and registered at ClinicalTrials.gov (Registration No. ChiCTR2400086758). The trial was conducted in accordance with the principles of the Declaration of Helsinki. Written informed consent was obtained from all participants prior to enrollment.

Consent for Publication

This was deemed not applicable.

Disclosure

No competing interests that could bias the study are apparent.