HCG Test - A Qualitative Test To Confirm Pregnancy

Submitted on March 27, 2012

An hCG test, more commonly known as the hCG pregnancy test, is a qualitative test done to confirm pregnancy. This test is done to find out the actual amount of hCG present in the blood. This is also often known as beta testing.

Reasons for HCG Test

The hCG blood test may be ordered for many different reasons. This test may be used to determine whether a pregnancy is ectopic. It is also used to monitor the pregnancy of women whose pregnancy is failing or those who have had a miscarriage in the past. If there is a suspicion of germ cell tumors or diseases like the trophoblastic disease, then too the hCG test is ordered. hCG tests can also determine anomalies in the testicles and the ovaries. If a germ cell tumor has been diagnosed, the hCG test is ordered at regular intervals to determine the effectiveness of the treatment.

The serum hCG test can be ordered immediately after a woman has missed her periods. However, it is recommended that the test be ordered about ten days after the period has been missed.

HCG Levels

For women who are not pregnant or do not have germ cell tumors, the hCG levels are not detectable. However, immediately with the onset of pregnancy, the hCG levels begin to rise significantly. In fact, every two to three days, the levels of hCG double in the blood serum. For pregnancies that are ectopic or are failing, the increase is much slower and therefore detection becomes easier. After miscarriage, the hCG levels fall down drastically. In such a case, the hCG levels should completely disappear from the blood stream. However, if that doesn’t happen, if is an indication of some leftover tissue which is producing hCG. In such a case, a surgery to remove the tissue may be necessary.

For patients who are being treated for trophoblastic disease, the test is ordered to detect any recurrence. The falling hCG levels are an indication of success in the treatment. However, if the hCG levels continue to rise, it means that the cancer is not responding to therapy and there needs to be a change in the treatment. If the levels fall down and then rise again, it is an indication of recurrence of the cancer.

Results for HCG Test

If the tests are performed very early in the pregnancy, they may not register the accurate levels of hCG, therefore giving a false report. If there is presence of protein or blood in the urine, that too could interfere with the reports. The results are also affected if the urine is very dilute, therefore the person who’s taking the test should not drink a lot of water before the test.