Quantitative hCG Blood Test
A quantitative human chorionic gonadotropin (HCG) test measures the specific level of HCG in the blood. HCG is a hormone produced in the body during pregnancy.
HCG can first be detected in a blood sample approximately 11 days after conception. Levels of hCG continue to double every 72 hours and reach their peak around eight to eleven weeks after conception. HCG levels then decline and level off, remaining steady for the rest of the pregnancy.
The hCG quantitative test is performed to:
determine the age of the fetus
diagnose abnormal pregnancies, such as ectopic pregnancy
diagnose a potential miscarriage
screen for Down syndrome
What are the risks?
Blood: During a blood draw, a hematoma (blood-filled bump under the skin) or slight bleeding from the puncture site may occur. After a blood draw, a bruise or infection may occur at the puncture site. The person doing this test may need to perform it more than once. Talk to your healthcare worker if you have any concerns about the risks of this test.
Normal ranges during 1st trimester:
=1 week: 5-50 milliInternational Units/mL (5-50 International Units/L)
2 weeks: 50-500 milliInternational Units/mL (50-500 International Units/L)
3 weeks: 100-10,000 milliInternational Units/mL (100-10,000 International Units/L)
4 weeks: 1,000-30,000 milliInternational Units/mL (1,000-30,000 International Units/L)
5 weeks: 3,500-115,000 milliInternational Units/mL (3,500-115,000 International Units/L)
6-8 weeks: 12,000-270,000 milliInternational Units/mL (12,000-270,000 International Units/L)
12 weeks: 15,000-220,000 milliInternational Units/mL (15,000-220,000 International Units/L)