Does this test have other names?
Human chorionic gonadotropin hormone test, serum pregnancy test
What is this test?
Human chorionic gonadotropin (HCG) is a type of hormone. Both men and women have small amounts of HCG in their body at all times. When a woman is pregnant, her body produces much more HCG than usual. In a healthy pregnancy, the amount of HCG in the blood increases substantially throughout the first three months. This blood test measures how much HCG is in your blood.
This test is the gold standard for determining whether you are pregnant. It shows that you are pregnant before an imaging test, such as an ultrasound, can detect a fetus. Ultrasound can show you that you are pregnant when HCG rises to 1,000 IU/L or greater.
Why do I need this test?
You may need this test if you have vaginal bleeding or cramping. This might indicate 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 two or more times, several days apart.
What other tests might I have along with this test?
Your healthcare provider might also order an ultrasound to screen for certain birth defects. Your blood may also be checked for two 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.
What do my test results mean?
Test results may vary depending on your age, gender, 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.
How is this test done?
The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand.
Does this test pose any risks?
Having a blood test with a needle carries 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.
What might affect my test results?
This test is quite reliable, but false-positives can be caused by:
Certain tumors that make HCG
Medicines containing HCG, such as those used in fertility treatments
Recent loss of pregnancy; it can take 60 days for HCG levels to return to normal
How do I get ready for this test?
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 illicit drugs you may use.