Effect of acupuncture on the opening time of implantation window and endometrial receptivity in controlled ovarian hyperstimulation rats during peri-implantation period

Dietary supplementation with N-acetyl-L-cysteine ameliorates hyperactivated ERK signaling in the endometrium that is linked to poor pregnancy outcomes following ovarian stimulation in pigs

BACKGROUND

Exogenous gonadotropin-controlled ovarian stimulation is the critical step in animal reproductive management, such as pig, sheep, bovine and other species. It helps synchronize ovulation or stimulate multiple ovulations. However, a number of evidence indicated an unexpected decrease in pregnancy outcomes following ovarian stimulation. This study aimed to explore the underlying mechanism of the pregnancy defect and develop a practical rescue strategy.

RESULTS

Compared with those in the control group, gilts that underwent ovarian stimulation showed a decrease in pregnancy rate, farrowing rate, and total number of piglets born. Stimulated gilts also showed an increase in estradiol (E2) levels. The supraphysiological E2 level was correlated with the decrease in the number of piglets born. Furthermore, we found that high levels of E2 impair uterine receptivity, as shown by the overproliferation of endometrial epithelial cells. In vitro mechanistic studies demonstrated that high levels of E2 hyperactivate FGF-FGFR-ERK signaling cascade in the uterine endometrium, and in turn induces overproliferation of endometrial epithelial cells. Of note, N-acetyl-L-cysteine (NAC) supplementation effectively inhibits ERK hyperphosphorylation and ameliorates endometrial epithelial overproliferation. Importantly, in vivo experiments indicated that dietary NAC supplementation, compared with ovarian stimulation group, improves the uterine receptivity in gilts, and significantly increases the pregnancy rate and total number of piglets born.

CONCLUSIONS

Ovarian stimulation-induced supraphysiological levels of E2 impairs uterine receptivity by hyperactivating FGF-FGFR-ERK signaling cascade, thereby reducing pregnancy rate and litter size. Supplementing NAC to a conventional diet for gilts ameliorates hyperactivated ERK signaling and improves uterine receptivity, thus rescuing adverse pregnancy outcomes following ovarian stimulation.

Feasibility of acupuncture as an adjunct intervention for ovulatory disorder infertility: A systematic review and meta-analysis

BACKGROUND

Acupuncture (AT) is widely used in treatment of ovulatory disorder infertility (ODI), but the safety and efficacy of AT for ODI still lack an evidence-based basis.

AIM

To evaluate the feasibility and effectiveness of AT as an adjunct intervention for ODI.

METHODS

The Cochrane Library, Embase, PubMed, VIP, China National Knowledge Infrastructure, WanFang Data, and Chinese biomedical literature databases were searched from inception to January 20, 2024. Two reviewers independently selected studies, collected data, and evaluated methodological quality through the Cochrane Risk of Bias tool. Revman 5.4 was used for meta-analysis, and the Grade system was performed to evaluate the level of evidence for the outcomes of the meta-analysis.

RESULTS

A total of 20 randomized controlled trials with 1677 ODI patients were included. Compared with the clomiphene citrate (CC) group, the AT plus CC group exhibited significant improvement of the pregnancy rate [relative risk (RR) = 1.68, 95% confidence interval (CI): 1.45-1.95, P < 0.00001, I² = 23%], ovulation rate (RR = 1.34, 95%CI: 1.22-1.47, P < 0.00001, I² = 32%), serum E₂ level [mean difference (MD) = 31.36, 95%CI: 21.83-40.88, P < 0.00001, I² = 97%], thickness of endometrium (MD = 1.76, 95%CI: 0.71-2.81, P = 0.001, I² = 98%) and decreasing miscarriage rate (RR = 0.25, 95%CI: 0.09-0.65, P = 0.005, I² = 0%), serum follicle-stimulating hormone level (MD = -2.10, 95%CI: -3.27 to -0.94, P = 0.0004, I² = 99%), serum luteinizing hormone level (MD = -6.94, 95%CI: -9.89 to -4.00, P < 0.00001, I² = 100%), and serum progesterone level (MD = -1.66, 95%CI: -2.98 to -0.34, P = 0.01, I² = 96%). The AT group had a more favorable effect than CC group for improving pregnancy rate (RR = 1.52, 95%CI: 1.33-1.73, P < 0.00001, I² = 0%), thickness of endometrium (MD = 2.48, 95%CI: 2.15-2.81, P < 0.00001, I² = 0%) and reducing miscarriage rate (RR = 0.23, 95%CI: 0.13-0.44, P < 0.00001, I² = 0%), serum follicle-stimulating hormone level (MD = -0.55, 95%CI: -0.86 to -0.24, P = 0.0005, I² = 0%), and serum progesterone level (MD = -0.24, 95%CI: -0.28 to -0.20, P < 0.00001). However, the level of evidence was predominantly assessed as very low to moderate.

CONCLUSION

AT can improve the pregnancy outcomes and sex hormone levels for patients with ODI. However, further studies are needed to confirm these findings.

Immediate Effect of Electro-acupuncture on Endometrial Blood Flow in Patients with Recurrent Implantation Failure: A Randomized Controlled Trial

OBJECTIVE

To investigate the immediate effects of electro-acupuncture (EA) on endometrial blood flow among recurrent implantation failure (RIF) patients.

METHODS

Eighty RIF patients, enrolled from March 2022 to December 2022, were randomly allocated into either the EA group (40 cases) or the waiting-list (WL) group (40 cases) by using a random number table. The EA group underwent acupuncture at points of Shenting (GV 24), Baihui (GV 4), Benshen (GB 13), bilateral Zigong (EX-CA 1), Huangshu (KI 16), Sanyinjiao (SP 6) and Xuehai (SP10), and electric acupuncture apparatus was connected to EX-CA 1, KI 16, SP 6, and SP 10 with disperse-dense waves at 4/20 Hz frequencies for 30 min after transvaginal ultrasound, while the WL group received no intervention. The primary outcome measured was the endometrial volume blood flow. The secondary outcomes included the bilateral uterine artery index, endometrial volume, endometrial blood flow type, vascular distribution index (VIMV) for endometrial and ovary, clinical pregnancy rate, and embryo implantation rate.

RESULTS

In the EA group, there was a notable decrease in the bilateral pulsatility index and a significant improvement in the endometrial blood flow type post-EA (P<0.05). Both the endometrial blood flow type and VIMV for the endometrium and right ovary were markedly higher in the EA group compared to the WL group post-treatment (P<0.05). Conversely, no significant disparities were observed in vascular index, flow index, vascular blood flow index, uterine arterial blood flow indices, endometrial volume, clinical pregnancy rate and embryo implantation rate between the two groups after treatment (P>0.05). Besides, no adverse events related to EA were observed.

CONCLUSIONS

EA can promptly ameliorate VIMV for the endometrial and right ovary, and endometrial blood flow type. Future randomized controlled trials are warranted to investigate the long-term effects of EA on blood flow of RIF patients and its implications for pregnancy outcomes. (Trial registration No. ChiCTR2200057377).