Human chorionic gonadotropin hormone test, serum pregnancy test, quantitative HCG
Human chorionic gonadotropin (HCG) is a type of hormone. This test measures how much HCG is in your blood.
Both men and women have small amounts of HCG in their body at all times. When a woman is pregnant, her body makes much more HCG than usual. In a healthy pregnancy, the amount of HCG in the blood increases a lot throughout the first 3 months.
This test is the gold standard for finding out if a woman is pregnant. It shows that you are pregnant before an imaging test, such as an ultrasound, can detect a fetus. Ultrasound can show that you are pregnant when HCG rises to 1,000 IU/L or greater.
Your healthcare provider may want you to have this test to see if you may be pregnant. You may also need this test if you have vaginal bleeding or cramping. This might mean that you could have an ectopic pregnancy or could lose your unborn baby. Your healthcare provider might also want to know how your pregnancy is progressing over a few days, so he or she may order this test 2 or more times, several days apart.
Your healthcare provider might also order an ultrasound to screen for certain problems if you are pregnant. Your blood may also be checked for 2 other hormones, estradiol and progesterone. Your levels of estradiol, a form of estrogen, can show how well the placenta is working. Progesterone levels also rise during pregnancy and can help your healthcare provider figure out if you are at risk for miscarriage or ectopic pregnancy.
Test results may vary depending on your age, sex, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you.
Normal levels of HCG in men and premenopausal women range from 0.02 to 0.8 IU/L. In early pregnancy, HCG levels can double every few days, peaking by about 10 weeks. After that, levels can either hold steady or begin to decline. Normal HCG levels during pregnancy can range from 20,000 to 200,000 IU/L.
Sometimes, measuring change in HCG levels over time can provide useful information. If HCG levels do not change as expected, it may mean the pregnancy could be lost.
The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand.
Having a blood test with a needle has some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore.
This test is quite reliable, but a false-positive test result can be caused by:
Certain tumors that make HCG
Medicines containing HCG, such as those used in fertility treatments
Recent loss of pregnancy, because it can take 60 days for HCG levels to return to normal
You don't need to prepare for this test. Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.