Identification of patients with persistent trophoblastic disease after complete hydatidiform mole by using a normal 24-hour urine hCG regression curve.

Objective: The aim of this study was to establish a reference 24-hour urine human chorionic gonadotropin (hCG) regression curve in patients with complete hydatidiform mole (CHM) as diagnostic tool in the prediction of persistent trophoblastic disease (PTD).

Methods: From 2004 to 2011, 312 cases suitable for this study were registered at the Hydatidiform Mole Registry of the Royal Women's Hospital Melbourne, Australia. hCG levels of 61 patients diagnosed as having PTD according to FIGO 2000 criteria were compared with the 95th-percentile (p95) of the normal regression curve derived from hCG levels of 251 cases of uneventful CHM.