Aim: We evaluated the reproducibility of an elevated luteinizing hormone (LH) level or elevated LH/follicle-stimulating hormone (FSH) ratio in different phases of the menstrual cycle in patients with polycystic ovary syndrome (PCOS). Furthermore, we evaluated the influence of cycle days and body mass index on LH levels using different days from menses or withdrawal bleeding.
Methods: Forty-three patients with PCOS and 37 controls were enrolled. All patients with PCOS had elevated LH levels and LH/FSH ratio, polycystic ovarian morphology and chronic anovulation at diagnosis. After their diagnoses, we measured serum LH and FSH in the early period and/or late period of the follicular phase.
Results: The rate of patients with elevated LH levels and LH/FSH ratio were significantly higher in the late phase than in the early phase in PCOS. In the early phase, only 52% of patients had elevated LH levels and LH/FSH ratio. We failed to demonstrate an inverse relationship between the LH level and BMI.
Conclusions: LH levels of patients with PCOS were strongly influenced by the days from menses or withdrawal bleeding. In the early period, the reproducibility of elevated LH levels or LH/FSH ratio was poor even in patients previously diagnosed with them.