Effect of Bushen Antai Decoction on Clinical Pregnancy Rate in Frozen-Thawed Embryo Transfer Cycles for Patients with Polycystic Ovary Syndrome: A Multicenter, Randomized, Controlled Clinical Trial

INTERVENTION: Chinese Medicine Group:Bushen Antai Decoction Granules (Astragalus membranaceus 30g, Angelica sinensis 20g, Ligusticum chuanxiong 10g, Cuscuta chinensis 20g, Taxillus chinensis 15g, Dipsacus asper 15g) were administered starting from day 5 of the menstrual cycle in the frozen‐thawed embryo transfer cycle, twice daily, one sachet per dose, for a total of 4 weeks of intervention.;Placebo Chinese Medicine Group:Placebo Granules (containing 5% original herb, 10% bitter gourd granules, 5% Scutellaria barbata granules, 0.2% tartrazine, 20% gelatin, 15% soluble starch, 5% flour, 39.8% placebo No.10) were administered starting from day 5 of the menstrual cycle in the frozen‐thawed embryo transfer cycle, twice daily, one sachet per dose, for a total of 4 weeks of intervention.; CONDITION: Infertility PRIMARY OUTCOME: Clinical pregnancy rate; SECONDARY OUTCOME: Endometrial Thickness (on the day of endometrial transformation);Embryo implantation rate;Persistent pregnancy rate;Live birth rate;Early miscarriage rate;Late miscarriage rate;Uterine endometrial hemodynamic parameters (RI, PI, S/D); INCLUSION CRITERIA: 1. Met the Rotterdam diagnostic criteria for PCOS; 2. Patients who have undergone at least two consecutive transfer cycles (fresh or thawed transfer cycles) and have not achieved clinical pregnancy after transferring two high‐quality blastocysts or four high‐quality cleavage‐stage embryos, and are planning to undergo another thawed transfer (with available high‐quality blastocysts in storage); 3. Age < 40 years; 4. Patients agreed to receive the treatment of this group and signed informed consent forms.1) Meeting the Rotterdam PCOS diagnostic criteria;