Patients
In the present study, a total of 104 PCOS patients (PCOS group) and 112 control women (control group) younger than 40 years old who were undergoing their in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles were retrospectively recruited in reproductive hospital affiliated with Shandong University from 2019 to 2021.To diagnose the polycystic ovary syndrome, we referred to the modified Rotterdam criteria11,12, including oligo- or anovulation combined with either hyperandrogenism or polycystic ovaries. Other causes of hyperandrogenism and ovulation dysfunction were excluded. Inclusion criteria for patients in control group were as follows: normal menstrual cycle, no endocrine abnormalities and normal ovarian and uterine morphology confirmed by either ultrasound or histological examination. The study was approved by the Ethics Committee of Reproductive Medicine of Shandong University with approval number 58, and signed informed consent was obtained from all participants.