Natural history of hydatidiform mole after primary evacuation.

From 1962 to 1978, 738 patients with hydatidiform mole were referred to the John I. Brewer Trophoblastic Disease Center of Northwestern University for follow-up and human chorionic gonadotropin (hCG) testing after evacuation. There was spontaneous regression of trophoblastic disease in 596 (80.8%) of the 738 patients. Of these 596 patients, regression occurred in 11 (1.8%) by day 10 after evacuation, in 124 (20.8%) between days 11 and 30, in 255 (42.8%) between days 31 and 60, and in 206 (34.6%) between days 61 and 170. Treatment with chemotherapeutic agents was required in 142 (19.2%) of the 738 patients; 125 (16.9%) of these had invasive mole (107 nonmetastatic and 18 metastatic) and 17 (2.3%) had choriocarcinoma (13 nonmetastatic and four metastatic). All 596 patients whose hCG titers declined spontaneously to normal levels have remained well and free of disease. All 142 treated patients experienced permanent remission. Thus, all 738 patients are well and free of disease 4 to 18 years after evacuation of the hydatidiform mole. The follow-up regimen described in this report furnishes information on natural history of molar pregnancies after evacuation and provides an excellent means by which all patients can be safely managed following termination of a hydatidiform mole.