Elevated serum human chorionic gonadotropin is diagnostic of choriocarcinoma.^[1][2]

• Human chorionic gonadotropin (HCG or b-HCG) is the most common tumor marker test used to diagnose GTD^[1]
• HCG is markedly elevated (usu. >10,000 IU)^[2]
• HCG is a very sensitive test for diagnosing most gestational trophoblastic tumors
• HCG is usually measured in the blood, but it can also be measured in the urine
• HCG levels are much higher in women with complete hydatidiform moles and gestational choriocarcinoma compared to HCG levels in women with a normal pregnancy
• With partial moles, the HCG level is higher than normal, but it is not as high as with other types of GTD
• With placental site tumors, the HCG level may be slightly higher than normal, but it is not considered a good marker for this type of tumor
• An HCG test can help find GTD after pregnancy or miscarriage as this hormone should not be present in the blood or urine soon afterward

• Human placental lactogen (hPL) is a tumor marker that may be used to follow women with placental site trophoblastic tumors
• Elevated hPL levels are found in women with some types of GTD

• Complete blood count can check for anemia from long-term (chronic) vaginal bleeding