Circulating inhibin forms in patients with hydatidiform mole.

Circulating inhibin forms have not been evaluated in patients with hydatidiform mole (HM) before evacuation of the mole. Serum inhibin A, inhibin B, pro-alphaC and hCG levels were determined by enzyme-linked immunosorbent assay in HM before and after evacuation of the mole (inhibin B only before evacuation). Before evacuation, inhibin B levels in HM were undetectable, and inhibin A levels were similar to those in normal women at the corresponding weeks of pregnancy. Pro-alphaC and hCG levels were higher in molar pregnancy than in normal pregnancy. After evacuation, pro-alphaC levels significantly fell in the patients with spontaneous resolution, but not in those who developed persistent trophoblastic disease (PTD). Both pro-alphaC and hCG levels were higher in the patients with PTD than in those with spontaneous resolution after evacuation, reflecting continued stimulation of the corpus luteum by lower, but still effective hCG levels, persistent trophoblastic tissues secreting pro-alphaC or both.