Inhibin as a marker for hydatidiform mole: a comparative study with the determinations of intact human chorionic gonadotrophin and its free beta-subunit.

OBJECTIVE: The purpose of the study was to evaluate plasma inhibin as a marker of hydatidiform mole and to compare the results with intact human chorionic gonadotrophin (hCG) and its free beta-subunit. DESIGN: Serial determinations of the plasma concentrations of inhibin, intact human chorionic gonadotrophin and its free beta-subunit in cases of hydatidiform mole over an average period of 140 days. PATIENTS: Five cases of hydatidiform mole, including patients with spontaneous remission after evacuation or persistent trophoblastic disease. MEASUREMENTS: Immunoreactive inhibin, hCG and free hCG beta-subunit were measured using standard enzyme immunoassays. RESULTS: Inhibin and free hCG beta-subunit levels were greater than in normal pregnant women at the same gestational age. Only intact hCG could detect the persistence of trophoblastic tissue. CONCLUSIONS: Our data suggest that inhibin, intact human chorionic gonadotrophin and free beta-subunit might be useful as diagnostic markers of molar pregnancies. However, the original method of intact hCG determination is still superior for follow-up.