HCG test is done to measure the human chorionic gonadotropin hormone level and presence in urine and blood. HCG test is commonly used to determine the pregnancy but also it can be used for birth defects screening. HCG hormone is produced during ovarian cancer too and also HCG test is used to determine the testicular cancer presence in men.
HCG production in body
HCG is produced by placenta cells. After the fertilizated egg attaches to the uterine wall, placenta starts developing and producing HCG. Secreted HCG can be found in both urine and blood. HCG can be determined in blood earlier than urine, it can be detected 6-12 days after the egg attached to the placenta wall.
How the HCG test is performed ?
HCG test is usually done in a tube of blood or urine sample. HCG blood test is a quantitative test and detects the spesific level of the HCG, but urine HCG test is done to determine the HCG presence as positive or negative. A tube of blood is needed for HCG blood test. Nurse/technician (phlebotomist) will insert a needle into your arm vein and collect a tube of blood. You may feel a little pain for a few seconds during the blood collection process.
If your doctor requests a HCG urine test, you’ll be given a urine sample cup. At most, half cup of urine sample would be necessary for HCG test. A sample from the first urine of the day would be more appropriate for HCG test because first morning urine is more concentrated and contains the highest level of HCG.
Preparation for HCG Test
If you use some medications please inform your doctor about this because your medicines may affect to your test results
If you will have a HCG in urine test don’t drink so much water before the test because this can make the urine so diluted and cause wrong negative results
Having the HCG test in very early days of pregnancy or wrong calculation of last menstrual period may cause decreased or wrong negative HCG results.So HCG test should be repeated a few days after.
Why the HCG Test is performed/ Purpose of HCG Test
- Determination of pregnancy
- Before a surgical operation (that may harm to the pregnancy)
- Determination of birth defects with the help of the other laboratory tests and screening tests
- Determination of ovarian and testicle cancers and monitoring treatment
- Detecting the ectopic pregnancy
- Diagnosing of other diseases that may raise HCG level
- Monitoring the development of pregnancy in first 2 months
The factors that may affect HCG Test result
- Heparin usage
- Antipsychotic medicines
- Hypnotic medicines
- Having HCG treatment for infertility
- Having a miscarriage a short time ago
HCG Test normal values
These values may change according to the laboratory, test method and the analyser
Blood HCG values
Men: Less than 5 U/L
Nonpregnant women: Less than 5 U/L
1 week pregnant: 5-50 U/L
2 week pregnant: 5-500 U/L
3 week pregnant: 100-10.000 U/L
4 week pregnant:1080-30.000 U/L
6-8 week pregnant: 3500-115.000 U/L
12 week pregnant: 12.000-270.000 U/L
Urine HCG values
Nonpregnant women: Negative
Pregnant women: Positive
High HCG values causes
- Very high values mean multiple pregnancy; more than one fetus like twins or triplets
- Birth defects like down syndrome
- Ovarian cancer
- Testicular cancer
- Stomach, pancreas, large intestine, lung, liver cancers may also increase the HCG level
Low HCG values causes
- Ectopic pregnancy
- Death of baby (fetal death)