What is Beta Human Chorionic Gonadotrophin (Beta HCG) ?
A pregnancy test measures a hormone in the body called human chorionic gonadotropin (hCG). hCG is produced during pregnancy and found in the blood and urine.
Testing for hCG can be used as soon as 10 days after conception to help determine if a person is pregnant. Measuring hCG can also help identify complications during pregnancy.
Purpose of the test
The standard use for a pregnancy test is to evaluate if a person is pregnant.
Both urine and blood tests for hCG can be used for this purpose, and repeat testing may be done to confirm a pregnancy.
Very early in a pregnancy, tests that measure the amount of hCG may also help assess the age of a fetus.
Less often, HCG tests can be used to:
- Identify or rule out an ectopic pregnancy, which is when a fertilized egg attaches or implants in an abnormal area
- Check for pregnancy prior to surgery or other medical treatments
- Screen for Down syndrome in pregnant people as part of prenatal screening
- Monitor a pregnancy that may be at risk of a miscarriage
- Help diagnose gestational trophoblastic disease (GTD), which is a term for pregnancy-related tumors.
What does the test measure ?
A pregnancy test measures a hormone in the body called human chorionic gonadotropin (hCG).
hCG is created at higher levels during pregnancy.
There are two different ways hCG results are reported:
- Qualitative: Qualitative hCG tests give a positive or negative result depending on the presence or absence of hCG in the sample.
Qualitative tests can be done using either a blood or urine sample. This type of testing is done most often to confirm a pregnancy.
- Quantitative: Quantitative hCG testing measures the amount of hCG present in the blood.
These tests frequently use a blood sample, but some urine tests can provide a degree of quantitative measurement.
Along with confirming a pregnancy, quantitative hCG tests can also be used as part of the diagnostic process for abnormal pregnancies and
other health conditions not related to pregnancy that can raise hCG levels.
When should I get a pregnancy test ?
A pregnancy test is most commonly done when a person is believed to be pregnant.
Testing may detect a pregnancy as soon as 10 days after conception.
The accuracy of pregnancy tests usually increases if taken at least 1-2 weeks after a missed menstrual period.
It may also be done when there are signs and symptoms that suggest an ectopic pregnancy or a pregnancy that is failing.
Signs of an ectopic pregnancy may include:
- Abnormal vaginal bleeding
- Low back pain
- Pain in the lower abdomen or pelvic area
- Cramping on one side of the pelvis
Additional and more severe symptoms may develop if an ectopic pregnancy is not identified and treated, so it is important for females of childbearing age to talk with a doctor if they notice these symptoms.
Pregnancy testing may also be done as a routine test prior to some medical treatments, such as surgeries or chemotherapy, that could potentially harm a fetus.
For any specific patient, a doctor is in the best position to determine if a pregnancy test is appropriate.