Human chorionic gonadotropin of pituitary origin in Chinese postmenopausal women: A single-center retrospective study

Objective: We analyze the characteristics and related factors of human chorionic gonadotropin (hCG) of pituitary origin to establish the reference interval to resolve clinical confusion and avoid harmful therapy to Chinese postmenopausal women with “positive” hCG. Materials and methods: This retrospective cohort study identified individuals who underwent hCG measurements at an academic hospital. Three gonadotropins (hCG, follicle stimulating hormone (FSH), and luteinizing hormone (LH)) was drawn from medical records. The age-stratified analyses were performed first. Then the correlations of hCG and FSH, LH as well as age were analysed. Finally, characteristics and associations of hCG, LH, and FSH were evaluated to identify pituitary hCG in postmenopausal women in clinical settings. Results: In total, 9796 cases from 11172 records met inclusion criteria and contributed 9796 hCG, 7541 FSH, and 7536 LH values. The upper reference interval for our cohorts was 5.3 IU/L. HCG, FSH, and LH concentration had no significant correlations with age. HCG moderately correlated with FSH (r = 0.47) and LH level (r = 0.53). However, it was FSH but not LH that manifested good clinical applicability. Conclusion: The prevalence of hCG≥5.0 IU/L and 5.3 IU/L in women ≥55 years is 2.8% and 2.3% in the study population from China. The level of hCG 5.3 IU/L was suggested to be the positive threshold for postmenopausal women. FSH≥40IU/L helps to distinguish the pituitary source of hCG in postmenopausal women whose serum hCG concentrations were between 5.3 and 16 IU/L.