Plasma human chorionic gonadotropin disappearance in hydatidiform mole: a central registry report from the Netherlands.

The disappearance time of serum human chorionic gonadotropin (hCG) after the evacuation of hydatidiform mole, partial mole, and hydropic degeneration was investigated. A statistically significant difference existed between the disappearance time of serum hCG after the evacuation of hydatidiform mole as compared with partial mole and hydropic degeneration. The average disappearance time of serum hCG after hydatidiform mole was 99.3 days, after partial mole 58.9 days, and after hydropic degeneration 50.7 days. It is not recommended to start chemotherapy for persistent trophoblastic disease before 100 days after the evacuation of hydatidiform mole, provided there is a steady downward course of the serum hCG level. It is advised to submit cases of supposed hydatidiform and partial moles to a tissue committee for a second opinion.