Measurements
Patient data were obtained from our centre records, included age, BMI,
systolic blood pressure (SBP), diastolic blood pressure (DBP), duration
and type of infertility, past medical history, a basic vaginal
ultrasound, a basal hormone profile evaluation and outcomes of
controlled ovarian hyperstimulation (COH), as well as laboratory and
clinical features of FET cycles. Blood samples of a basal hormone
profile were collected for assessment on days 2–5 of a spontaneous or
progestin-induced menstrual cycle in all women. All the hormonal assays
were performed in the laboratories of the Center for Reproductive
Medicine, Cheeloo College of Medicine, Shandong University.