Acupuncture for endometriosis: A systematic review and meta-analysis

This systematic review and meta-analysis evaluated the efficacy of acupuncture in the treatment of endometriosis-related pain, a condition that affects approximately 10% of women of reproductive age. Endometriosis is characterized by the presence of endometrium-like tissue outside the uterus, causing intense pelvic pain, dysmenorrhea, and significant impacts on quality of life. The authors conducted a comprehensive search across multiple databases through March 2023, including CENTRAL, PubMed, AMED, Embase, Epistemonikos, and CINAHL. Only randomized clinical trials using penetrating acupuncture as the primary intervention were included.

The study analyzed six clinical trials with a total of 331 participants, with sample sizes ranging from 18 to 106 participants. The mean age of participants was 29.9 years, and all had a confirmed diagnosis of endometriosis by laparoscopy or other imaging methods. The studies were performed in different countries, including China, Australia, Austria, Brazil, and the United States, providing geographic diversity to the data. Acupuncture protocols varied across studies, with some using fixed approaches and others allowing individualization of treatment.

The mean number of needles used was 12.8 per session, with frequently chosen points including Spleen 6, Liver 3, Stomach 36, and local points in the lower abdominal region. Treatment duration ranged from 5 to 12 weeks, with a frequency of one to two times per week. The results demonstrated clinically meaningful benefits of acupuncture. When compared with non-specific acupuncture, true acupuncture showed a large effect on the reduction of general pelvic pain (g = 1.54, 95% CI 0.92-2.16, p < 0.001), menstrual pain (g = 1.67, 95% CI 1.23-2.12, p < 0.001), and unspecified pelvic pain (MD = -2.77, 95% CI 2.15-3.38, p < 0.001).

Compared with usual care, acupuncture also demonstrated a moderate benefit on menstrual pain (g = 0.9, 95% CI 0.15-1.64, p = 0.02). The certainty of evidence ranged from moderate to very low, according to GRADE assessment. The methodological quality of the studies, evaluated by the NICMAN scale, showed improvement over time, with more recent studies showing better reporting quality. Most studies reported low rates of adverse events, suggesting that acupuncture is safe when administered by qualified professionals.

One event of hypotension was reported, which resolved within 30 minutes. Some studies also reported reductions in the use of analgesic medication in the acupuncture groups. Limitations include small sample sizes in most studies, heterogeneity in treatment protocols, and limited follow-up time to assess long-term benefits. The variable methodological quality and risk of bias in some studies also affected the certainty of evidence.

The clinical implications are promising, suggesting that acupuncture should be considered as a treatment option for women with endometriosis, especially those who have not responded adequately to other interventions and where pelvic pain is a primary concern. The authors emphasize the need for future studies with larger samples, longer follow-up, and better reporting quality following STRICTA guidelines.