Study of Time-restricted Eating (TRE) to Clinical Pregnancy Rate in PCOS Women With Glucose Metabolism Disorder Via IVF/ICSI

In this multicenter randomized controlled study, investigators plan to recruit 254 patients, aged 20-38, with PCOS and glucose metabolism disorder. PCOS diagnostic criteria based on Rotterdam 2003 criteria, glucose metabolism disorder are diagnosed by 1998 WHO diagnostic criteria, with HbA1c≤7%. Participants selected are overweight or obese (24Kg/m2 ≤ BMI ≤40Kg/m2), and are planned to start the 1st/ 2nd cycle of IVF/ ICSI. Investigators divide these patients randomly into 2 groups (each group with 127 patients): metformin only group (control group) and TRE with metformin group. Every participant receives the specific treatment according to the group for at least 6 weeks. During the intervention period, follow-ups, blood chemistry tests and examinations are recorded every 2 weeks. After the intervention period, IVF/ ICSI is carried out. GnRH-agonist- or/and hCG-triggered is used for ovarian stimulation. Ovum retrieval will be carried out 34-36h after ovarian stimulation. Blood hCG is tested after 12-14 days after embryonic transfer. For patients with positive hCG, clinical pregnancy is confirmed by observing gestational sac via transvaginal ultrasound after 4-5 weeks. Investigators compare the terminal pregnancy-related result and metabolic changes between 2 groups to determine the effect and the possible mechanisms of TRE on IVF/ ICSI clinical pregnancy rate of PCOS with glucose metabolism disorder patients.