Efficacy and safety of acupuncture for pregnancy-related low back pain: A systematic review and meta-analysis

This systematic review and meta-analysis evaluated the efficacy and safety of acupuncture for the treatment of pregnancy-related low back pain (PRLBP), a condition that affects between 20% and 90% of pregnant women globally. PRLBP is defined as recurrent or constant pain lasting more than one week, originating in the lumbar spine or pelvis, frequently occurring in the second and third trimesters of pregnancy and possibly persisting in the postpartum period. The researchers conducted a systematic search across eight databases from inception through January 2022, including Cochrane Library, PubMed, EMBASE, and Chinese databases. Twelve randomized controlled trials involving 1,302 patients were included, with 634 in the experimental group and 668 in the control group.

The methodology followed PRISMA guidelines and was registered with PROSPERO. The included studies investigated different acupuncture modalities, including traditional acupuncture, electroacupuncture, and warm acupuncture, compared with physical therapy, standard care, medications, or no treatment. The most commonly used acupuncture points were BL-23, BL-25, BL-26 to BL-30, BL-60, SI-3, KI-3, GB-30, and Ashi points. Treatment duration ranged from 4 to 10 weeks, with frequencies of 1 to 5 sessions per week.

The primary outcome was change on the Visual Analog Scale (VAS) for pain, while secondary outcomes included effectiveness rate, preterm birth rate, and adverse events. The analysis of results showed that acupuncture was significantly superior to controls in reducing pain, with a mean difference of -1.60 points on the VAS scale (95% CI: -1.76 to -1.45). The effectiveness rate was also higher in the acupuncture group (OR: 6.92, 95% CI: 2.44 to 19.67). Importantly, there was no significant difference in preterm birth rate between groups (RR=0.38, 95% CI: 0.24 to 0.61, p=0.97), demonstrating that the treatment did not increase obstetric risks.

Reported adverse events were minimal and included local hematoma, drowsiness, fatigue, dizziness, headache, and nausea, all considered mild and transient. No serious adverse events were reported. The methodological quality assessment showed that six studies described adequate randomization methods, but only three used some form of blinding. Overall quality of evidence was rated as moderate by the GRADE system for the main outcomes.

The clinical implications are significant, considering that pharmacologic options for pain during pregnancy are limited due to concerns about fetal safety. Acetaminophen and nonsteroidal anti-inflammatory drugs, although they are first-line treatments, present cardiovascular, gastrointestinal, and renal risks, in addition to limited efficacy. Acupuncture emerges as a safe and effective non-pharmacologic alternative. The analgesic mechanism of acupuncture involves integrative processes in the central nervous system, stimulation of endogenous pain control mechanisms, release of opioid peptides, modulation of neurotransmitters such as serotonin and norepinephrine, and reduction of local inflammation.

These findings are consistent with recent medical guidelines, including recommendations from the American Academy of Family Physicians and the American College of Physicians, which endorse acupuncture as a first-line treatment for low back pain. Limitations of the study include significant heterogeneity between studies (I²=93%), different diagnostic criteria and gestational weeks, small sample sizes in some studies, and variable methodological quality. Most studies used acupuncture as an adjuvant therapy, making it difficult to evaluate the isolated effect of the technique. Future research should focus on higher-quality clinical trials with larger samples, more rigorous methodology, and standardization of treatment protocols.