Blood based Pregnancy Test

What are pregnancy tests?

Pregnancy tests usually help us to measure the hormone level in the body. As you know there is a change in the hormonal level as the placenta produces a hormone called HCG or human chorionic gonadotropin which is also referred to as pregnancy hormone. If this hormone is detected in the urine sample then this test reveals that you are pregnant.

Difference between urine and blood tests for detecting pregnancy?

There are two ways to detect pregnancy and both these ways give you an accurate test result. There are urine pregnancy test kits that are sold over the counter to confirm pregnancy and these tests measure the amount of HCG level in the body.

Blood samples taken to confirm pregnancy is used to measure the HCG level in your body. In spite of getting the confirmation about the impending pregnancy using home pregnancy test kit the doctor recommends a blood test as this test picks up the level of hormone in your body even before the urine test can confirm your pregnancy.

Blood test and its working

Blood tests to confirm pregnancy are done in two ways i.e. quality and quantity. Quality of the blood sample shows the level or amount of HCG that is present in the body to prove pregnancy while quantity tests reports show the increase in the level of HCG in the body and to help detect any abnormality in the level so as to prevent any unwanted complications at a later stage.

How are the test performed?

The blood sample is drawn from your forearm vein, and collected in a vial the blood is then tested in a lab under the supervision of a medical professional and the results are passed on to your doctor. Most of the time the test results are given on the same day but in certain cases the results may take a few days.

What are the chances of the blood test going wrong?

Most of the time the pregnancy test reports are accurate but then sometimes due to unforeseen reasons the test results may be incorrect. The reasons can be varied like:

• Use of fertility drugs sometimes can give a false test report
• Sometimes the blood test is conducted too early leading to the non-detection of HCG hormone level.

What is the necessity of undergoing a blood test?

Though the home pregnancy test kit has shown positive results you yet need to undergo a pregnancy blood test and the reasons are:

• Your doctor can confirm your pregnancy and can start with prenatal care
• To check out the progress of the fetus and incase of any health related problems.
• To join in WIC related public funded pregnancy programs.

Which are the other pregnancy blood tests that are performed?

PAPP-A (Pregnancy Associated Plasma Protein Screening) tests is done to check the level of protein and identify any chromosome abnormalities.

AFP (Alpha-Fetoprotein Screening) usually blood test is done in the second trimester to
a) Check the presence of multiple pregnancy
b) Give more precise due date
c) Neural tube defects and Down’s Syndrome

Hereditary and any family history of genetic disorders are usually found in genetic screening.

Blood group of the mother, anemia, diabetes, sexually transmitted diseases etc.