a case-control study is currently under way in beijing , people 's republic of china , involving approximately 165 patients with invasive moles or choriocarcinoma , 165 with hydatidiform moles , and 330 population controls , who were matched to the patients with invasive moles or choriocarcinoma on age and interval since last pregnancy .
C0020217
hydatidiform moles
C0008493
invasive moles