At a Glance
Why Get Tested?
To confirm and monitor pregnancy or to diagnose trophoblastic disease or germ cell tumours
When to Get Tested?
As early as 10 days after a missed menstrual period (some methods can detect hCG even earlier, at one week after conception) or if a doctor thinks that your symptoms suggest ectopic pregnancy, a failing pregnancy, trophoblastic disease or germ cell tumours
A urine sample collected first thing in the morning or a blood sample taken from a vein in the arm
The Test Sample
What is being tested?
hCG is a protein produced in the placenta of a pregnant woman. A pregnancy test is a specific blood or urine test that can detect hCG and confirm pregnancy. This hormone can be detected 10 days after a missed menstrual period, the time period when the fertilised egg is implanted in the woman's uterus. With some methods, hCG can be detected even earlier, at one week after conception.
During the early weeks of pregnancy, hCG is important in maintaining function of the corpus luteum (the mass of cells that forms from a mature egg). Production of hCG increases steadily during the first trimester (8 - 10 weeks), peaking around the 10th week after the last menstrual cycle. Levels then fall slowly during the remainder of the pregnancy. hCG is no longer detectable within a few weeks after delivery. hCG is also produced by some germ cell tumours and increased levels are seen in trophoblastic disease.
How is the sample collected for testing?
hCG is commonly detected in urine. The preferred specimen is a random urine sample collected first thing in the morning. hCG can also be measured in blood taken from a vein in the arm.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Ask a Laboratory Scientist
NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.