Objective: To examine the effects and mechanisms of transcutaneous electrical acupoint stimulation (TEAS) on pregnancy outcomes in women undergoing in vitro fertilization (IVF)-embryo transfer (ET).
Design, setting, and participants: This efficacy study was a multicenter, randomized, controlled clinical trial (RCT) in women receiving IVF-ET. The mechanistic study was a single-center RCT.
Interventions: The participants received TEAS vs. no TEAS treatment.
Main outcome measures: In the efficacy study, the primary outcomes were the rates of clinical pregnancy, embryo implantation, and live birth. In the mechanistic study, sex hormones and endometrial protein expression were examined.
Results: Ultimately, 739 participants were enrolled (367 and 372 in the TEAS and control groups, respectively). The clinical pregnancy rate was higher in the TEAS group than in the controls (55.1% vs. 46.7%, P = 0.03). There were no significant differences in embryo implantation, biochemical pregnancy, and live birth rates between the two groups (all P > 0.05) in the study population. In women > 35 years, the clinical pregnancy rates, embryo implantation rates and live birth rates in the TEAS and control groups were 48.9% vs. 23.7% (P = 0.004),30.8 vs. 13.9% (P = 0.001) and 34.0% vs. 19.7% (P = 0.06) respectively. In the mechanistic study with 120 participants, on the theoretical embryo implantation day, better developed endometrial pinopodes, elevated endometrial integrin α1β1/αVβ3, leukemia inhibitory factor, and elevated serum progesterone levels were found in the TEAS group compared with controls.
Conclusion: TEAS significantly improved the clinical pregnancy rate in women undergoing IVF-ET, especially in women of older age. It might be due to improved endometrial receptivity.