Final answer:
Serial hCG tests can be used to monitor pregnancy progression, diagnose medical conditions, and track treatment effectiveness.
Step-by-step explanation:
Serial hCG tests, which measure the levels of human chorionic gonadotropin (hCG) in the body over time, can be interpreted to monitor pregnancy progression or diagnose certain medical conditions. In pregnancy, a series of hCG tests can help determine if the pregnancy is progressing normally. Rising hCG levels indicate a healthy pregnancy, while decreasing or plateauing levels may suggest a problematic pregnancy such as an ectopic pregnancy or miscarriage. Outside of pregnancy, serial hCG tests can be used to monitor and diagnose medical conditions like certain tumors or track the effectiveness of treatment.