Hormonal contraception and trophoblastic sequelae after hydatidiform mole (a Gynecologic Oncology Group Study).

A prospective randomized study was undertaken to determine whether the administration of oral contraceptives after the evacuation of a hydatidiform mole affects the human chorionic gonadotropin serum level in a way that leads to an increased frequency in the diagnosis of postmolar trophoblastic disease. Between 1981 and 1988, 266 patients were randomly assigned to either oral contraceptives or barrier contraception after evacuation of a hydatidiform mole. Patients were followed up until serum levels of human chorionic gonadotropin were normal or until specific criteria for the diagnosis of postmolar trophoblastic disease were met. Twenty-three percent of patients receiving oral contraceptives had postmolar trophoblastic disease, whereas those using a barrier method had a rate of 33%. The median time to spontaneous regression in the oral contraceptives group was 9 weeks, whereas the median time to regression in the barrier group was 10 weeks. Twice as many patients in the barrier group became pregnant in the immediate follow-up period. We conclude that oral contraceptives are the preferred method of contraception after evacuation of a hydatidiform mole.