Objective  To investigate the clinical characteristics and significance of diagnosis and treatment associated with persistent real low-level elevation of human chorionic gonadotropin (hCG).

  Methods  Six patients diagnosed with persistent real low-level hCG elevation at Peking Union Medical College Hospital in the period from August 2011 to March 2015 were collected. Clinical records of the 6 patients were reviewed to retrospectively analyze clinical features, diagnosis and treatment approaches, and follow-up results.

  Results  Among the 6 patients, 3 were secondary to uterine curettage for hydatidiform moles, and the other 3 had received chemotherapy for invasive moles, in whom the median chemotherapy cycle number was 8 and all experienced failure of at least one chemotherapy regimen. The median follow-up time was 24 months. The median period between the termination of treatment and the initial low-level hCG elevation was 5.5 months. The median duration of low-level hCG elevation was 16.5 months. Four patients had no evidence of progression, 1 patient progressed to choriocarcinoma, and 1 presented with the hCG level decreasing to the normal range after spontaneous delivery.

  Conclusion  Persistent real low-level hCG elevation may persist for a long time and not respond to chemotherapy. Long-term close monitoring is necessary, but treatment is not recommended.