Home > Health Library > Human Chorionic Gonadotropin (HCG)
The human chorionic gonadotropin (hCG) test is
done to check for the
hormone hCG in blood or urine. Some hCG tests measure
the exact amount. Some just check to see if the hormone is present. HCG is
made by the
placenta during pregnancy. The test can be used to
see if a woman is pregnant. Or it can be done as part of a screening test for birth
HCG may also be made by certain tumors, especially those that come from an egg or sperm. (These are called germ cell tumors.) HCG levels
are often tested in a woman who may have tissue that is not normal growing in her uterus.
The test also may be done to look for
molar pregnancy or a cancer inside the uterus. Several hCG tests may be done
after a miscarriage to be sure a molar pregnancy is not present. In a man, hCG
levels may be measured to help see if he has cancer of the
An egg is normally fertilized by
a sperm cell in a
fallopian tube. Within 9 days the fertilized egg moves down the
fallopian tube into the uterus. It then attaches (implants) to the wall of the uterus.
After the fertilized egg implants, the growing placenta starts releasing hCG
into your blood. Some hCG also gets passed in your urine. HCG can be found in
the blood before the first missed menstrual period. This can be as early as 6 days after
the egg implants.
HCG helps to keep your pregnancy going. It also affects the
development of your
baby (fetus). Levels of hCG go up fast in the
first 14 to 16 weeks after your last menstrual period. They are the highest around
the 14th week following your last period. They then go down gradually. The amount that
hCG goes up early in pregnancy can give information about your pregnancy and
the health of your baby. Soon after delivery, hCG can no longer be found in
More hCG is released in a multiple pregnancy, such as
twins or triplets, than in a single pregnancy. Less hCG is released if the
fertilized egg implants in a place other than the uterus, such as in a
fallopian tube. This is called an
The level of hCG in the blood is often used as part of a screening for
birth defects in a maternal serum triple or quadruple screening test. These tests are usually done between 15 and 20 weeks of pregnancy to check the levels of three or four
substances in a pregnant woman's blood. The triple screen checks
hCG, alpha-fetoprotein (AFP), and a type of
estrogen (unconjugated estriol, or uE3). The quad screen checks these
substances and the level of the hormone inhibin A. The levels of these
substances—along with a woman's age and other factors—help the doctor figure out
the chance that the baby may have certain problems or birth defects.
In some cases, screening tests are combined in the first
trimester to look for Down syndrome. This screening
test uses an ultrasound to measure the thickness of the skin at the back of
the fetus's neck (nuchal translucency). It also includes a blood test for the levels hCG and a protein called pregnancy-associated plasma protein
A (PAPP-A). This test works about as well as the second-trimester maternal
serum quad screening.footnote 1
HCG urine tests are usually used
for regular pregnancy testing. The test does not measure the exact amount of
hCG, but it shows if hCG is present. Home versions of this test are easy to find and buy.
Health Tools help you make wise health decisions or take action to improve your health.
A test for human chorionic gonadotropin
(hCG) is done to:
If a blood sample is collected, you do
not need to do anything before you have this test.
If a urine test
is done, the first urine of the day is generally the best to use because it has
the highest level of hCG. A urine sample collected at least 4 hours after
you last urinated will also have high amounts of hCG.
Human chorionic gonadotropin (hCG) may
be measured in a sample of blood or urine.
The health professional
drawing blood will:
If possible, collect a sample
from the first urine of the day.
The blood sample is taken from a vein
in your arm. An elastic band is wrapped around your upper arm. It may feel
tight. You may feel nothing at all from the needle, or you may feel a quick
sting or pinch.
You may feel anxious while you wait for results of an
hCG test done to check the health of your baby.
In most cases, there is no pain with
collecting a urine sample.
There is very little chance
of a problem from having a blood sample taken from a vein.
Collecting a urine sample does not cause problems.
The human chorionic gonadotropin (hCG)
test is done to measure the amount of the
hormone hCG in blood or urine to see if a woman
is pregnant. HCG may also be measured to see if cancer of the ovaries or
testicles is present.
These numbers are just a guide. The range for "normal" varies from lab to lab. Your lab may have a different range. Your lab report should show what range your lab uses for "normal." Also, your doctor will evaluate your results based on your health and other factors. So a number that is outside the normal range here may still be normal for you.
international units per liter (IU/L)
Pregnant women, 1 week of gestation (about 3 weeks after
the last menstrual period):
Pregnant women, 2 weeks of gestation (about 4 weeks after the
Pregnant women, 3 weeks of gestation (about 5 weeks after the
Pregnant women, 4 weeks of gestation (about 6 weeks after the
Pregnant women, 6–8 weeks of gestation (about 8–10 weeks after the
Pregnant women, 12 weeks of gestation (about 14 weeks after
Pregnant women, 13–16 weeks of gestation (about 15–18 weeks after
Up to 200,000
You may not be able to have the test, or the results may not be helpful, if:
American College of Obstetricians and Gynecologists (2007, reaffirmed 2008). Screening for fetal chromosomal abnormalities. ACOG Practice Bulletin No. 77. Obstetrics and Gynecology, 109(1): 217–227.
Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Other Works Consulted
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
Wapner RJ, et al. (2009). Prenatal diagnosis of congenital disorders. In RK Creasy et al., eds., Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice, 6th ed., pp. 221–274. Philadelphia: Saunders Elsevier.
ByHealthwise StaffPrimary Medical ReviewerSarah Marshall, MD - Family MedicineE. Gregory Thompson, MD - Internal MedicineAdam Husney, MD - Family MedicineSpecialist Medical ReviewerSiobhan M. Dolan, MD, MPH - Reproductive Genetics
Current as ofJune 15, 2016
Current as of:
June 15, 2016
Sarah Marshall, MD - Family Medicine & E. Gregory Thompson, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Siobhan M. Dolan, MD, MPH - Reproductive Genetics
To learn more about Healthwise, visit Healthwise.org.
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