Effectiveness of herb-partitioned moxibustion on the navel for pregnancy outcomes in patients with recurrent implantation failure undergoing in vitro fertilization and embryo transfer: a study protocol for a randomized controlled trial

BACKGROUND: Recurrent implantation failure (RIF) in the majority of patients undergoing in vitro fertilization and embryo transfer (IVF-ET) is caused by various factors such as maternal age, embryo quality, endometrial receptivity (ER), and immunity. The incidence of RIF is usually between 5 and 10%. Previous studies have shown that herb-partitioned moxibustion on the navel is one of the treatment methods of acupuncture with a positive effect on pregnancy. However, its application in the treatment of RIF has not been reported. Therefore, this study aims to evaluate the effectiveness and safeness of herb-partitioned moxibustion on the navel in improving the outcome of frozen embryo transfer (FET) in patients with RIF. METHODS: This study conducts a randomized controlled trial (RCT). It is planned to recruit 210 patients undergoing RIF for FET from Affiliated Hospital of Shandong University of Traditional Chinese Medicine and randomly divide them into the treatment group and the control group in a ratio of 1:1. The patient of the treatment group will be treated with herb-partitioned moxibustion on the navel once a week for three consecutive menstrual cycles. No intervention will be used in the control group for 3 menstrual cycles. In the fourth menstrual cycle, all patients will undergo artificial cycle to prepare the endometrium for FET. The pregnancy outcomes will be recorded after a 3-month follow-up. Primary outcome will be assessed as the ongoing pregnancy rate compared with the control group. Secondary outcomes include the endometrial type, resistance index (RI), pulsatility index (PI) of the bilateral uterine artery, endometrial blood flow, serum estradiol (E(2)), progesterone (P), biochemical pregnancy rate, implantation rate, and clinical pregnancy rate. DISCUSSION: If the results show that the herb-partitioned moxibustion on the navel can improve IVF-ET outcomes in patients with RIF, it will be recommended in clinical practice. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) ChiCTR2100043954. Registered on 8 July 2021. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-022-06156-5.