Final answer:
hCG is monitored after a hydatidiform mole to detect the possibility of recurrent molar pregnancies or the development of choriocarcinoma, a type of cancer.
Step-by-step explanation:
Human chorionic gonadotropin (hCG) is a hormone that is critical during early pregnancy. After a hydatidiform mole, which is an abnormal growth of trophoblasts (the cells that normally develop into the placenta), hCG is monitored to detect the possibility of recurrent molar pregnancies. If hCG levels remain high or increase after the removal of a molar pregnancy, it may suggest the presence of persistent trophoblastic disease or the development of choriocarcinoma, which is a type of cancer that can occur after a molar pregnancy. This makes monitoring hCG levels essential for the patient's health and management of potential complications associated with a hydatidiform mole.