hCG (Pregnancy Test), Quantitative
CPT Code(s):
84703
Turnaround Time:
4 hours
Specimen Requirements
Preferred Specimen:
Serum
Minimum Volume:
1.0 mL
Transport Container:
Serum Separator Tube (SST) or Red Top Tube
Transport Temperature:
Room Temperature
Collection Instructions:
Allow blood to clot completely prior to centrifugation. Separate serum from cells within 45 minutes of collection.
Rejection Criteria:
Plasma specimen; gross hemolysis; lipemia; improper labeling
Stability Criteria
Room Temperature:
8 hours
Refrigerated:
3 days
Frozen:
30 days
Clinical Significance
The hCG (Human Chorionic Gonadotropin), Quantitative test holds specific clinical significance and diagnostic use in determining and monitoring pregnancy, assessing the viability of the pregnancy, and diagnosing certain medical conditions.
The specific clinical significance and diagnostic use of the hCG, Quantitative test include:
1. Pregnancy Confirmation: The hCG, Quantitative test is commonly used to confirm the presence of pregnancy. Human chorionic gonadotropin is a hormone produced by the developing placenta after implantation occurs. Detecting hCG in the blood or urine helps confirm pregnancy and differentiate it from other conditions that may cause similar symptoms.
2. Monitoring Pregnancy Progression: The hCG, Quantitative test is useful for monitoring the progression of pregnancy. In normal pregnancies, hCG levels increase significantly during the early weeks and then gradually decline. Serial measurements of hCG levels can help healthcare providers assess the viability and progress of pregnancy. Abnormal hCG trends may indicate potential complications, such as ectopic pregnancy or miscarriage.
3. Evaluation of Pregnancy Viability: The hCG, Quantitative test is also utilized to assess the viability of a pregnancy. Comparing the rate of hCG rise or fall to expected patterns can provide insights into the likelihood of a viable pregnancy. Abnormally low or plateauing hCG levels may indicate a nonviable or ectopic pregnancy, while appropriate hCG rise suggests a potentially viable intrauterine pregnancy.
4. Monitoring Treatment for Trophoblastic Diseases: The hCG, Quantitative test is essential in monitoring and managing trophoblastic diseases, such as gestational trophoblastic neoplasia (GTN) and choriocarcinoma. Serial hCG measurements guide treatment decisions, evaluate response to chemotherapy or surgical interventions, and assess the effectiveness of disease management.
5. Diagnosis and Monitoring of Germ Cell Tumors: Certain germ cell tumors, such as testicular or ovarian tumors, can produce hCG. The hCG, Quantitative test aids in diagnosing and monitoring these tumors by measuring hCG levels. It helps assess tumor response to treatment and provides valuable information for disease staging and management.
6. Assessment of Certain Medical Conditions: The hCG, Quantitative test is occasionally used to evaluate specific medical conditions unrelated to pregnancy. In males, elevated hCG levels may indicate certain testicular cancers or hormone-secreting tumors. In females, elevated hCG levels may be observed in certain ovarian conditions or as a side effect of certain medications.
It is important to note that the interpretation of hCG, Quantitative test results should consider the gestational age, clinical context, and specific reference ranges used by the laboratory performing the test. Additionally, hCG levels alone cannot provide a definitive diagnosis, and further diagnostic tests and clinical evaluation may be required for accurate assessment and management.
In summary, the hCG, Quantitative test has specific clinical significance in confirming pregnancy, monitoring pregnancy progression, evaluating pregnancy viability, monitoring treatment for trophoblastic diseases, diagnosing and monitoring germ cell tumors, and assessing certain medical conditions. By measuring hCG levels in the blood, this test provides valuable information for clinical decision-making, optimizing patient care, and improving outcomes related to pregnancy and certain medical conditions.