Acupuncture-assisted embryo transfer techniques: Research frontiers and future directions

Table 1 Key indicators and analysis of clinical studies

Index	Unit	Sample size	Trial population	Acupoint selection	Controls	Results
Pregnancy rate	Ataturk University of Erzurum, Turkey	72	The mean age of infertile women undergoing IVF was 30.9 years ± 3.7 years	First stage: H7, GV20. Second stage: CV3, GV20, 1IV3, ST30, SP8. Third stage: LI4, SP6, ST36	Insert the needle to a depth of 1 to 2 inches. Keep it for 30 minutes	CPR increased. The pregnancy rate was 63.9% in the acupuncture group and 33.3% in the control group
Success rate of IVF	Medical University of Shiraz, Iran	186	Women undergoing IVF treatment	HT7, PC6, RN6, DU20, SP6, RN4	Electroacupuncture	Significantly increase the success rate of IVF and improve the CPR
Oocyte quality	Shandong University of Chinese Medicine	60	Elderly women undergoing IVF	RN12, RN4, DU20, KI3, BL23, SP6, LR3, ST25, BL32	Insert the needle 10-30 mm, once every ten minutes, and stay for 30 minutes before each removal	Effectively improve the quality of female oocytes and improve the pregnancy outcome of IVF-embryo transfer
Planting rate	Faculty of Medicine of ABC, Clinic for Human Reproduction, Santo André, São Paulo, Brazil	84	Infertile patients who have had at least two failed IVF treatment	BL18, BL22, BL23, BL52, CV3, CV4, CV5, CV7, GV4	Combine acupuncture with moxibustion	The pregnancy rate in the acupuncture group was 35.7%, significantly higher than the 71% in the control group and 10.7% in the sham acupuncture group
Mental state	Ataturk University of Erzurum, Turkey	72	Infertile women with an average age of 30.9 years ± 3.7 years who underwent IVF	First stage: H7, GV20. Second stage: CV3, GV20, 1IV3, ST30, SP-8. Third stage: LI4, SP6, ST-36	Insert the needle to a depth of 1 to 2 inches. Allow it to remain in place for 30 minutes	Relieve anxiety and stress before embryo transfer and improve the probability of embryo transfer success

CPR: Clinical pregnancy rate; IVF: In vitro fertilization.

Table 2 Basic information of included fundamental researches

Nature of acupuncture	Number of participants (intervention/control)	Age (intervention/control)	Control	Acupuncture points	Time of acupuncture/frequencies/cycles	Outcomes	Ref.
TA	40 (20/20)	32.65/31.20	No adjuvant treatment	LR3, SP6, CV4, SP10, ST36	30 minutes/2 days/between the time of menstruation and the simulated transplantation day	Endometrial thickness, ndometrial typing, Pulsatility index, Resistance index, Peak systolic velocity/diastolic velocity, expression of endometrial receptor-related factors, expression of key molecules and gene expression of the AMP-activated protein kinase/mammalian target of rapamycin pathway, CPR, embryo implantation rate	Qi et al[13]
TA	12 (6/6)	31/27.5	No adjuvant treatment	CV4, ST36, SP6, BL23, BL32	30 minutes/2 days/two menstrual cycles during in vitro fertilization and embryo transfer	CPR, endometrium thickness, identification, functional analysis and validation of differentially expressed genes, competing endogenous RNA network	Cheng et al[14]
TA	62 (20/20/22 in the young control group)	37.70/37.27/29.83	Routine ovulation induction combined with sham acupuncture	RN4, SP6, EX-CA1	30 minutes/3 times a week until the day of human chorionic gonadotropin injection	The score of kidney qi deficiency syndrome, the 2 pronuclei fertilization rate, HQER and CPR	Xia et al[8]
EA	76 (38/38)	28.4/29.2	Pseudo-acupuncture	RN12, ST25, SP15, GB26, CV6, CV4, SP10, ST40, ST36, SP9	25 minutes/twice a week until the day of oocyte collection/3 menstrual cycles	The phlegm-dampness syndrome. Score, the index of rigidity scores, the number of oocytes retrieved, CPR, transplantable embryo rate;, HQER, live birth rate, expression of insulin receptor substrate-1, PI3K and GLUT4 mRNA	Xiang et al[15]
EA	66 (33/33)	31.76/33.73	Placebo needle puncture	CV3, CV6, ST29, SP6, LI4/Th12–L2, S2–S4	25 minutes duration/2days/3 menstrual cycles	CPR, oocyte retrieval, Fertilization, HQER, expression of PI3K, protein kinase B, Forkhead box o3 mRNA	Wu et al[16]

CPR: Clinical pregnancy rates; EA: Electroacupuncture; HQER: High-quality embryo rate; PI3K: Phosphatidylinositol-3-kinase; TA: Traditional acupuncture.

Table 3 Characteristics of included reviews and meta-analysis

Ref.	Number of studies (total sample)	Nature of acupuncture	Control	Time of acupuncture	Outcomes
Manheimer et al[17]	16 (4012)	TA/EA	No adjuvant treatment or sham acupuncture	Before and after ET	CPR/LBR
Wang et al[18]	7 (516)	MA/AA/TEAS/EA	No adjuvant treatment	During COH, during ET	CPR/ET
Gu et al[5]	31 (4450)	TA/EA/AA/TEAS/LA	No adjuvant treatment or sham acupuncture	During COH, during ET	CPR/BRP/OPR/MR
Zhu et al[19]	14 (1130)	TA/EA/TEAS	No adjuvant treatment or sham acupuncture	Before and after frozen-thawed embryo transfer	CPR/BRP/LBR/ET/endometrial pattern
Qian et al[20]	30 (6344)	TA/EA/LA/AA	No adjuvant treatment or sham acupuncture	During COH, during ET	BPR/CPR/LBR/OPR
Xie et al[21]	27 (6166)	MA/EA/AA/TA	No adjuvant treatment or sham acupuncture	Before and after ET	CPR/LBR
Smith et al[22]	20 (5130)	MA/EA/LA/TEAS/dry needling	No adjuvant treatment or sham acupuncture	Before and after ET	CPR/LBR/OPR/MR

AA: Auricular acupuncture; BRP: Biochemical pregnancy rate; CPR: Clinical pregnancy rate; COH: Controlled ovarian hyperstimulation; EA: Electrical acupuncture; ET: Endometrial thickness; LA: Laser acupuncture; LBR: Live birth rate; MA: Manual acupuncture; MR: Miscarriage rate; OPR: Ongoing pregnancy rate; TA: Traditional acupuncture; TEAS: Transcutaneous electrical acupoint stimulation.

Table 4 Patents relating to acupuncture treatment for embryo transfer

Category	Patent ID	Title	Assignee	Inventor	Priority date	Publication date	Grant date
Non-invasive Neurostimulation Category	US-11534600-B2	Non-invasive nerve stimulation to treat or prevent autism spectrum disorders and other disorders of psychological development	Electrovore, Inc	Simon BJ, Errico JP, Raffle JT	2009-03-20	2022-12-27	2022-12-27
Wearable Stimulation Device Category	US-11413294-B2	Monolithic intravaginal rings comprising progesterone and methods of making and uses thereof	Ferring BV	Ahmed SU, Tsao JX, Mahashabde A, Harrison DD	2020-01-31	2020-12-31	2022-08-16
Implantable Acupuncture Electrostimulation System Category	US-8965511-B2	Implantable electroacupuncture system and method for reducing hypertension	Valencia Technologies Corporation	Greiner JH, Peterson DKL, Thenuwara C	2011-08-30	2015-02-24	2015-02-24
Acupuncture Stimulation Device Category	CN-202376635-U	Acupoint stimulation apparatus used for increasing extracorporeal fertilization-embryo transplantation pregnancy rate	Han JS, Sun W, Zhang R	Han JS, Sun W, Zhang R, Ma XJ	2011-11-03	2012-08-15	2012-08-15