Human chorionic gonadotropin and free subunits' serum levels in patients with partial and complete hydatidiform moles.

Serum levels of hCG and its free subunits were measured in patients with partial and complete hydatidiform moles and in women with normal 10-week pregnancies. whereas complete moles had higher levels of percent-free beta-hCG than partial moles (2.4 versus 1.0; P less than or equal to .005), partial moles had higher levels of percent-free alpha-hCG than complete moles (0.85 versus 0.17; P less than or equal to .005). Normal 10-week pregnancies had lower levels of both percent-free beta-hCG and percent-free alpha-hCG than partial moles (0.40 versus 1.0, P less than or equal to .005 and 0.27 versus 0.85, P less than or equal to .005, respectively). Percent-free beta-hCG and beta-hCG levels did not distinguish which patients with complete mole were more likely to develop persistent post-molar tumor. The trophoblastic cells in complete and partial moles differ significantly in the manner in which they secrete the free subunits of hCG.