Human Chorionic Gonadotropin Test (HCG)-Why am I having this test?

Human chorionic gonadotropin test is done to determine whether you are pregnant. It can also be used:

• To diagnose an abnormal pregnancy.
• To determine whether you have had a failed pregnancy (miscarriage) or are at risk of one.

What is being tested?

This test checks the level of the human chorionic gonadotropin (hCG) hormone in the blood. This hormone is produced during pregnancy by the cells that form the placenta. The placenta is the organ that grows inside your womb (uterus) to nourish a developing baby. When you are pregnant, hCG can be detected in your blood or urine 7 to 8 days before your missed period. It continues to go up for the first 8–10 weeks of pregnancy.

The presence of hCG in your blood can be measured with several different types of tests. You may have:

• A urine test.
  • Because this hormone is eliminated from your body by your kidneys, you may have a urine test to find out whether you are pregnant. A home pregnancy test detects whether there is hCG in your urine.
  • A urine test only shows whether there is hCG in your urine. It does not measure how much.
• A qualitative blood test.
  • You may have this type of blood test to find out if you are pregnant.
  • This blood test only shows whether there is hCG in your blood. It does not measure how much.
• A quantitative blood test.
  • This type of blood test measures the amount of hCG in your blood.
  • You may have this test to:
    • Diagnose an abnormal pregnancy.
    • Check whether you have had a miscarriage.
    • Determine whether you are at risk of a miscarriage.

What kind of sample is taken?

Two kinds of samples may be collected to test for the hCG hormone.

• Blood. It is usually collected by inserting a needle into a blood vessel.
• Urine. It is usually collected by urinating into a germ-free (sterile) specimen cup. It is best to collect the sample the first time you urinate in the morning.

How do I prepare for this test?

No preparation is needed for a blood test.

For the urine test:

• Let your health care provider know about:
  • All medicines you are taking, including vitamins, herbs, creams, and over-the-counter medicines.
  • Any blood in your urine. This may interfere with the result.
• Do not drink too much fluid. Drink as you normally would, or as directed by your health care provider.

How are the results reported?

Depending on the type of test that you have, your test results may be reported as values. Your health care provider will compare your results to normal ranges that were established after testing a large group of people (reference ranges). Reference ranges may vary among labs and hospitals. For this test, common reference ranges that show absence of pregnancy are:

• Quantitative hCG blood levels: less than 5 IU/L.

Other results will be reported as either positive or negative. For this test, normal results (meaning the absence of pregnancy) are:

• Negative for hCG in the urine test.
• Negative for hCG in the qualitative blood test.

What do the results mean?

Urine and qualitative blood test

• A negative result could mean:
  • That you are not pregnant.
  • That the test was done too early in your pregnancy to detect hCG in your blood or urine. If you still have other signs of pregnancy, the test will be repeated.
• A positive result means:
  • That you are most likely pregnant. Your health care provider may confirm your pregnancy with an imaging study (ultrasound) of your uterus, if needed.

Quantitative blood test

Results of the quantitative hCG blood test will be interpreted as follows:

• Less than 5 IU/L: You are most likely not pregnant.
• Greater than 25 IU/L: You are most likely pregnant.
• hCG levels that are higher than expected:
  • You are pregnant with twins.
  • You have abnormal growths in the uterus.
• hCG levels that are rising more slowly than expected:
  • You have an ectopic pregnancy (also called a tubal pregnancy).
• hCG levels that are falling:
  • You may be having a miscarriage.

Talk with your health care provider about what your results mean.

Questions to ask your health care provider

Ask your health care provider, or the department that is doing the test:

• When will my results be ready?
• How will I get my results?
• What are my treatment options?
• What other tests do I need?
• What are my next steps?

Summary

• A human chorionic gonadotropin test is done to determine whether you are pregnant.
• When you are pregnant, hCG can be detected in your blood or urine 7 to 8 days before your missed period. It continues to go up for the first 8–10 weeks of pregnancy.
• Your hCG level can be measured with different types of tests. You may have a urine test, a qualitative blood test, or a quantitative blood test.
• Talk with your health care provider about what your results mean.