1. Renner, RM, Jensen, JT, Nichols, MD, et al. Pain control in first-trimester surgical abortion: a systematic review of randomized controlled trials. Contraception 2010; 81(5): 372–388.
Google Scholar | Crossref | Medline2. Ng, EHY, So, WZ, Gao, J, et al. The role of acupuncture in the management of subfertility. Fertil Steril 2008; 90(1): 1–13.
Google Scholar | Crossref | Medline3. Hantoushzadeh, S, Alhusseini, N, Lebaschi, AH. The effects of acupuncture during labour on nulliparous women: a randomised controlled trial. Aust N Z J Obstet Gynaecol 2007; 47(1): 26–30.
Google Scholar | Crossref | Medline4. Helms, JM . Acupuncture for the management of primary dysmenorrhea. Obstet Gynecol 1987; 69: 51–56.
Google Scholar | Medline5. Witt, CM, Reinhold, T, Brinkhaus, B, et al. Acupuncture in patients with dysmenorrhea: a randomized study on clinical effectiveness and cost-effectiveness in usual care. Am J Obstet Gynecol 2008; 198(2): 166e1–8.
Google Scholar | Crossref | Medline6. Yuan, J, Purepong, N, Kerr, DP, et al. Effectiveness of acupuncture for low back pain: a systematic review. Spine 2008; 33: E887–E900.
Google Scholar | Crossref | Medline7. Linde, K, Allais, G, Brinkhaus, B, et al. Acupuncture for migraine prophylaxis. Cochrane Database Syst Rev 2019; 1: CD001218.
Google Scholar8. Manheimer, E, Linde, K, Lao, L, et al. Metaanalysis: acupuncture for osteoarthritis of the knee. Ann Intern Med 2007; 146(12): 868–877.
Google Scholar | Crossref | Medline9. Stener-Victorin, E, Waldenstrom, U, Nilsson, L, et al. A prospective randomized study of electro-acupuncture versus alfentanil as anaesthesia during oocyte aspiration in in-vitro fertilization. Hum Reprod 1999; 14(10): 2480–2484.
Google Scholar | Crossref | Medline10. Ndubisi, C, Danvers, A, Gold, MA, et al. Auricular acupuncture as an adjunct for pain management during first trimester abortion: a randomized, double-blinded, three arm trial. Contraception 2019; 99(3): 143–147.
Google Scholar | Crossref | Medline11. World Health Organization Regional Office for the Western Pacific . Standard acupuncture nomenclature. 2nd ed. Manila: World Health Organization Regional Publications, 1993.
Google Scholar12. Han, Z, Jiang, YH, Wan, Y, et al. Endomorphin-1 mediates 2 Hz but not 100 Hz electroacupuncture analgesia in the rat. Neurosci Lett 1999; 274: 76–78.
Google Scholar | Crossref13. Han, JS . Acupuncture: neuropeptide release produced by electrical stimulation of different frequencies. Trends Neurosci 2003; 26(1): 17–22.
Google Scholar | Crossref | Medline14. Ramsay, MA, Savege, TM, Simpson, BR, et al. Controlled sedation with alphaxalone-alphadolone. Br Med J 1974; 920: 656–659.
Google Scholar | Crossref15. Shek, DTL . The Chinese version of the state-trait anxiety inventory: its relationship to different measures of psychological well-being. J Clin Psychol 1993; 49(3): 349–358.
Google Scholar | Crossref | Medline16. Li, HW, Wong, CY, Lo, SS, et al. Effect of local lignocaine gel application for pain relief during suction termination of first-trimester pregnancy: a randomized controlled trial. Hum Reprod 2006; 21(6): 1461–1466.
Google Scholar | Crossref | Medline17. Lin, YC, Hsu, ES. Acupuncture for pain management. New York: Springer, 2014.
Google Scholar | Crossref18. Andersson, S, Lundeberg, T. Acupuncture – from empiricism to science – functional background to acupuncture effects in pain and disease. Med Hypotheses 1995; 45(3): 271–281.
Google Scholar | Crossref | Medline19. Wang, H, Xie, Y, Zhang, Q, et al. Transcutaneous electric acupoint stimulation reduces intra-operative remifentanil consumption and alleviates postoperative side-effects in patients undergoing sinusotomy: a prospective, randomized, placebo-controlled trial. Br J Anaesth 2014; 112(6): 1075–1082.
Google Scholar | Crossref | Medline20. Peng, LC, Jiang, KQ, Wu, GL, et al. Mechanism of acupuncture anesthesia for analgesia of the operative region of thyroid gland. Zhongguo Zhen Jiu 2008; 28(12): 910–912.
Google Scholar | Medline21. Melzack, R, Wall, PD. Pain mechanisms: a new theory. Science 1965; 150: 971–978.
Google Scholar | Crossref | Medline22. Zhang, R, Lao, L, Ren, K, et al. Mechanisms of acupuncture-electroacupuncture on persistent pain. Anesthesiology 2014; 120(2): 482–503.
Google Scholar | Crossref | Medline23. Belanger, E, Melzack, R, Lauzon, P. Pain of first-trimester abortion: a study of psychosocial and medical predictors. Pain 1989; 36(3): 339–350.
Google Scholar | Crossref | Medline24. Kan, A, Ng, E, Ho, PC. The role and comparison of two techniques of paracervical block for pain relief during suction evacuation for first-trimester pregnancy termination. Contraception 2004; 70(2): 159–163.
Google Scholar | Crossref | Medline25. Zhang, J, Cao, X. Neuronal specificity of needling acupoints at same meridian: a control functional magnetic resonance imaging study with electroacupuncture. Acupunct Electrother Res 2007; 32(3–4): 179–193.
Google Scholar | Crossref | Medline26. Han, J . Acupuncture analgesia: areas of consensus and controversy. Pain 2011; 152(3): S41–S48.
Google Scholar | Crossref | Medline27. Medoff, ZM, Colloca, L. Placebo analgesia: understanding the mechanisms. Pain Manag 2015; 5(2): 89–96.
Google Scholar | Crossref | Medline