Clinical utility of human chorionic gonadotropin and alpha-subunit measurements.

Sensitive and quantitative radioimmunoassays of serum human chorionic gonadotropin (hCG) levels have expanded the utility of hCG measurements from a simple pregnancy test into a powerful tool applicable in an increasing number of clinical disorders. Proper management of gestational trophoblastic disease depends on reliable and sensitive hCG determinations. Information on the in vivo doubling time of hCG in early pregnancy can be used in more effective diagnosis of early pregnancy disorders such as ectopic pregnancy and spontaneous abortion. Serum hCG is an effective tumor marker in the staging and management of testicular cancer and potentially of nontrophoblastic cancers. Measurement of glycoprotein hormone alpha-subunit levels has clinical application in gestational trophoblastic disease, abnormal pregnancy, and some forms of nontrophoblastic malignancy.