Objective: The aim of this study was to determine how often patients with complete hydatidiform mole (CHM) who spontaneously achieve normal human chorionic gonadotrophin (hCG) levels subsequently develop persistent or recurrent gestational trophoblast disease.
Methods: Four hundred and fourteen cases of CHM registered at the Hydatidiform Mole Registry of Victoria were reviewed retrospectively after molar evacuation. Maternal age, gestational age, gravidity and parity were determined for each patient, as well as the need for chemotherapy.
Results: Among the 414 patients, 55 (13.3%) required chemotherapy for persistent trophoblastic disease. None of the patients whose hCG levels spontaneously fell to normal subsequently developed persistent molar disease.
Conclusion: Weekly hCG measurements are recommended for all patients until normal levels are achieved. For patients who attain normal hCG levels within 2 months after evacuation, it seems safe to discontinue monitoring once normal levels are achieved. Patients who fail to achieve normal hCG levels by 2 months after evacuation should be monitored with monthly hCG measurements for 1 year after normalisation to assure sustained remission.