Clinical features of early-stage nonhydropic mole for diagnosis of persistent trophoblastic disease.

Objectives: To characterize the clinical features of "nonhydropic" hydatidiform mole and to investigate regression of serum human chorionic gonadotropin (hCG) as an aid in detecting persistent trophoblastic disease after nonhydropic hydatidiform mole.

Methods: Our study included women with histologically diagnosed nonhydropic molar pregnancies. Women did not exhibit macroscopic or characteristic ultrasonographic appearances specific to hydatidiform mole. Regression of serum hCG levels was compared with abortions of nonmolar pregnancies, which were histologically confirmed.

Results: Among 34 nonhydropic molar pregnancies, 32 complete hydatidiform moles were analyzed, excluding two partial hydatidiform moles. Compared with nonmolar aborted pregnancies, pre-evacuation hCG levels were significantly higher in the 32 complete hydatidiform moles. The 32 molar pregnancies progressed to 24 cases of spontaneous remission and eight cases of persistent trophoblastic disease. Among patients with spontaneous remission, the time at which serum hCG levels became undetectable and the onset of first postabortion menstruation were similar to those in patients who had nonmolar abortions. In all patients who experienced regression, serum hCG was undetectable after the third postabortion menstruation. In all patients with persistent trophoblastic disease, serum hCG levels exceeded 25 milli-international units/mL 4 weeks after evacuation.

Conclusion: Without histological confirmation, it is difficult to diagnose nonhydropic molar pregnancy based solely on clinical presentation. Follow-up studies of serum hCG levels 4 weeks after abortion and after the third postabortion menstruation may aid in detecting impending persistent trophoblastic disease.

Level Of Evidence: II.