The Role of Erzhi Tiangui Formula in Expected POR Women Undergoing IVF-ET

In recent years, traditional Chinese medicine (TCM) has been involved with all aspects of assisted reproductive technology (ART), but it remains a long way from being applied to in vitro fertilization and embryo transfer (IVF-ET). Moreover, there is a lack of high-quality clinical research conducted on a large scale. The Erzhi Tiangui formula, which originated from Gui-Cheng Xia, a national TCM master, was composed and established by Professor Fang Lian, who was a national famous TCM practitioner and "Qi Huang scholar," based on her professional experience of more than 40 years. After more than 20 years of basic and clinical investigation, it has demonstrated its effectiveness in optimizing female reproductive function. We therefore adopt Erzhi Tiangui Fang as a pretreatment for IVF-ET in patients with expected poor ovarian response in order to improve their reproductive outcomes. Outpatient clinics at 10 public tertiary hospitals in the country are involved in the study. It is planned to enroll 480 elderly patients with poor ovarian response between January 2023 and December 2025. The Erzhi Tiangui formula group and placebo group will be randomly assigned in a 1:1 ratio through stratified block randomization. Both groups will use a fixed gonadotrophin releasing hormone (GnRH) antagonist protocol for controlled ovarian hyperstimulation. In IVF cycles, Erzhi tiangui formula and placebo will be administered from day 2 or 3 of the previous menstrual cycle to the trigger day. Approximately 5 to 6 weeks will be required for the intervention to be completed. The primary outcome is the number of retrieved oocytes, i.e., the number of oocytes observed under a microscope after oocyte retrieval monitored by transvaginal ultrasound. Secondary outcomes are the ovarian stimulation outcomes, embryonic laboratory outcomes, pregnancy outcomes, obstetric and neonatal outcomes.

Women aged 35 to 43 years with POR who were scheduled for IVF or intracytoplasmic sperm injection (ICSI) treatment were eligible for enrollment. The diagnosis of POR was based on the Bologna criteria.

Women were excluded if they: (i) had a body mass index (BMI) ≥ 35 kg/m2; (ii) failed to obtain clinical pregnancy after three or more IVF/ICSI cycles; (iii) had a history of two or more recurrent pregnancy losses; (iv) were diagnosed with uterine abnormalities using hysteroscopy or diagnosed with hydrosalpinx using hysterosalpingography; (v) had a history of chemotherapy with cytotoxic agents, pelvic radiotherapy, or severe systemic diseases; (vi) had taken Chinese herbal medicines or other therapies affecting ovarian function within three months before study enrollment; or (vii) were allergic to the ingredients of EZTG granules or placebo.